Jupiter’s moons: How to see and enjoy them

The shadow of Io, one of Jupiter’s moons, is cast on the giant planet’s cloud tops. This image was captured by the JunoCam camera aboard NASA’s Juno spacecraft, currently orbiting Jupiter. The image was acquired on September 19, 2019. Image via NASA/ JPL-Caltech/ SwRI/ MSSS/ Kevin M. Gill (public domain).

Jupiter will be brightest in early December, so now is a good time to look for its 4 largest moons. For more events, visit EarthSky’s night sky guide.

Exciting news, EarthSky family! The 2025 Lunar Calendar Presale is live!

How to see Jupiter’s moons

All you need is a good pair of binoculars (or a telescope) to see the four largest moons of the biggest planet in our solar system, Jupiter.

Three of the four moons are bigger than Earth’s moon. And one – Ganymede – is the largest moon in the solar system. These four satellites are collectively called the Galilean moons to honor the Italian astronomer Galileo, who discovered them in 1610. November 2024 is a great month to look for Jupiter’s four large moons. That’s because the king of planets is nearing opposition – when Earth will sweep between it and the sun – in early December. So the distance between Earth and Jupiter is now less than usual. And Jupiter is bright!

From Earth, through a small telescope or strong binoculars, the moons of Jupiter look like tiny starlike pinpricks of light. But you’ll know they’re not stars because you’ll see them stretched out in a line that bisects the giant planet.

Depending on what sort of optical aid you use, you might glimpse just one moon or see all four. If you see fewer than four moons, that might be because a moon is behind – or in front of – Jupiter. If a moon is in front of the planet, you probably can’t see it. The moon is too tiny and gets lost from our view. But observers do sometimes see a moon shadow crossing Jupiter’s cloud-tops. That event is called a transit.

Going from the moon closest to Jupiter to the outermost, their order going outward from Jupiter is Io, Europa, Ganymede and Callisto.

What you’ll see

Writing at SkyandTelescope.com, Bob King has said:

Etched in my brain cells is an image of a sharp, gleaming disk striped with two dark belts and accompanied by four starlike moons through my 2.4-inch [6 cm] refractor in the winter of 1966. A 6-inch [15 cm] reflector will make you privy to nearly all of the planet’s secrets …

When magnified at 150x or higher [Jupiter’s 4 largest moons] lose their starlike appearance and show disks that range in size from 1.0″ to 1.7″ (arcseconds). Europa is the smallest and Ganymede the largest.

Ganymede also casts the largest shadow on the planet’s cloud tops when it transits in front of Jupiter. Shadow transits are visible at least once a week with ‘double transits’ – two moons casting shadows simultaneously – occurring once or twice a month. Ganymede’s shadow looks like a bullet hole, while little Europa’s more resembles a pinprick. Moons also fade away and then reappear over several minutes when they enter and exit Jupiter’s shadow during eclipse. Or a moon may be occulted by the Jovian disk and hover at the planet’s edge like a pearl before fading from sight.

Images of Jupiter’s moons from the EarthSky community

View at EarthSky Community Photos. | Nanci McCraine at Finger Lakes, New York, took this photo on September 30, 2023, and wrote: “I noticed craggy edges around Jupiter. Zooming in, I spotted this line of 4 straight lights across the planet that I assume are satellites.” That is correct! Binoculars or a small telescope will show Jupiter’s moons.

View at EarthSky Community Photos. | Cathy Adams in St. Stephen, New Brunswick, Canada, captured 2 of Jupiter’s moons and giant Jupiter itself on September 3, 2022. Cathy wrote: “After so many cloudy nights I was fortunate to get a beautiful clear one! And it was absolutely wonderful to enjoy a night out observing, and imaging our neighboring planets!!” Thank you, Cathy!

View at EarthSky Community Photos. | Around the time of its yearly opposition, Jupiter is brightest in our sky, best through a telescope, and visible all night. Michael Terhune in Lunenburg, Massachusetts, captured Jupiter in August 2021. He wrote: “My sharpest image of Jupiter! Showing 2 of its Galilean satellites, Io and Europa. The Great Red Spot is also visible.” Thank you, Michael.

More images

View at EarthSky Community Photos. | Meiying Lee in Taipei, Taiwan, took these images of Jupiter’s 4 largest moons over the course of a single night. She wrote: “I always thought that to see obvious changes in the 4 major satellites of Jupiter would take several nights of continuous observation. Later, I discovered that the Galilean satellites move very fast around Jupiter.” See the volcanic moon Io move behind Jupiter and emerge on the other side just a few hours later? Amazing! Thanks, Meiying.

Meiying Lee in Taipei, Taiwan, shared this chart with us on October 6, 2023, and wrote: “From the evening of August 15 to the early morning of August 16, 2021, the Galilean satellites experienced very exciting changes. Callisto, Ganymede, and Europa passed through the surface of Jupiter one after another, while Io was occulted by Jupiter. This resulted in the rare phenomenon that there were no Galilean satellites around Jupiter for 20 minutes late at night on August 16th. Finally, before dawn, the 4 satellites appeared around Jupiter one after another. I watched the Galilean satellites show all night, it was really exciting!” Thank you, Meiying.

View at EarthSky Community Photos. | Sona Shahani Shukla in New Delhi, India, caught a transit of the innermost Galilean moon, Io, across the face of Jupiter on July 7, 2021, and wrote: “Io appears to be skimming Jupiter’s cloud tops, but it’s actually 310,000 miles (500,000 km) from Jupiter. Io zips around Jupiter in 1.8 days, whereas our moon circles Earth every 28 days. The conspicuous black spot on Jupiter is Io’s shadow and is about the size of the moon itself (2,262 miles or 3,640 km across). This shadow sails across the face of Jupiter at 38,000 mph (17 km per second).” Thank you, Sona!

Special viewings of Jupiter’s moons

As with most moons and planets, the Galilean moons orbit Jupiter around its equator. We do see their orbits almost exactly edge-on, but, as with so much in astronomy, there’s a cycle for viewing the edge-on-ness of Jupiter’s moons. This particular cycle is six years long. So every six years we view Jupiter’s equator – and the moons orbiting above its equator – at the most edge-on. During these special times, we can see the moons eclipse and cast shadows on not just giant Jupiter but on each other.

In 2021 we were able to view a number of mutual events (eclipses and shadow transits) involving Jupiter’s moons. The next cycle of mutual events will be in 2027.

Another special event, a rare triple transit, occurs on October 18, 2025, when three of Jupiter’s moons will pass in front of the giant planet at once. The last time Earth could witness a triple transit was in 2021. Triple transits are not visible from all parts of the globe, however.

You can find information here for dates and times to observe the Galilean moons

Composite image of Jupiter and its 4 Galilean moons. From left to right the moons are Io, Europa, Ganymede and Callisto. The Galileo spacecraft obtained the images to make this composite in 1996. Image via NASA Photojournal.

Jupiter at opposition in December 2024

On December 7, 2024, Jupiter is at opposition, when the planet is opposite the sun in the sky as seen from Earth. When Earth passes directly between Jupiter and the sun, we’ll see Jupiter rise at sunset and set at sunrise. Opposition is the middle of the best time of the year to see a planet, since that’s when the planet is up and viewable all night and is generally closest for the year. But any time Jupiter is visible in your sky, you can view Jupiter’s four major moons.

So if you get a chance, grab some binoculars or a small telescope and go see Jupiter’s Galilean moons with your own eyes!

Click here for recommended sky almanacs; they can tell you Jupiter’s rising time in your sky.

Opposition – when Earth is directly between Jupiter and the sun – is the best time to observe the largest planet and its 4 Galilean moons. In 2024, Jupiter’s opposition is December 7. Image via EarthSky.

Bottom line: November and December 2024 are great months for seeing Jupiter’s moons Io, Europa, Ganymede and Callisto with binoculars or a small telescope.

Check here for dates and times to observe the Great Red Spot

The post Jupiter’s moons: How to see and enjoy them first appeared on EarthSky.

from EarthSky https://ift.tt/ZEqRD8v

The shadow of Io, one of Jupiter’s moons, is cast on the giant planet’s cloud tops. This image was captured by the JunoCam camera aboard NASA’s Juno spacecraft, currently orbiting Jupiter. The image was acquired on September 19, 2019. Image via NASA/ JPL-Caltech/ SwRI/ MSSS/ Kevin M. Gill (public domain).

Jupiter will be brightest in early December, so now is a good time to look for its 4 largest moons. For more events, visit EarthSky’s night sky guide.

Exciting news, EarthSky family! The 2025 Lunar Calendar Presale is live!

How to see Jupiter’s moons

All you need is a good pair of binoculars (or a telescope) to see the four largest moons of the biggest planet in our solar system, Jupiter.

Three of the four moons are bigger than Earth’s moon. And one – Ganymede – is the largest moon in the solar system. These four satellites are collectively called the Galilean moons to honor the Italian astronomer Galileo, who discovered them in 1610. November 2024 is a great month to look for Jupiter’s four large moons. That’s because the king of planets is nearing opposition – when Earth will sweep between it and the sun – in early December. So the distance between Earth and Jupiter is now less than usual. And Jupiter is bright!

From Earth, through a small telescope or strong binoculars, the moons of Jupiter look like tiny starlike pinpricks of light. But you’ll know they’re not stars because you’ll see them stretched out in a line that bisects the giant planet.

Depending on what sort of optical aid you use, you might glimpse just one moon or see all four. If you see fewer than four moons, that might be because a moon is behind – or in front of – Jupiter. If a moon is in front of the planet, you probably can’t see it. The moon is too tiny and gets lost from our view. But observers do sometimes see a moon shadow crossing Jupiter’s cloud-tops. That event is called a transit.

Going from the moon closest to Jupiter to the outermost, their order going outward from Jupiter is Io, Europa, Ganymede and Callisto.

What you’ll see

Writing at SkyandTelescope.com, Bob King has said:

Etched in my brain cells is an image of a sharp, gleaming disk striped with two dark belts and accompanied by four starlike moons through my 2.4-inch [6 cm] refractor in the winter of 1966. A 6-inch [15 cm] reflector will make you privy to nearly all of the planet’s secrets …

When magnified at 150x or higher [Jupiter’s 4 largest moons] lose their starlike appearance and show disks that range in size from 1.0″ to 1.7″ (arcseconds). Europa is the smallest and Ganymede the largest.

Ganymede also casts the largest shadow on the planet’s cloud tops when it transits in front of Jupiter. Shadow transits are visible at least once a week with ‘double transits’ – two moons casting shadows simultaneously – occurring once or twice a month. Ganymede’s shadow looks like a bullet hole, while little Europa’s more resembles a pinprick. Moons also fade away and then reappear over several minutes when they enter and exit Jupiter’s shadow during eclipse. Or a moon may be occulted by the Jovian disk and hover at the planet’s edge like a pearl before fading from sight.

Images of Jupiter’s moons from the EarthSky community

View at EarthSky Community Photos. | Nanci McCraine at Finger Lakes, New York, took this photo on September 30, 2023, and wrote: “I noticed craggy edges around Jupiter. Zooming in, I spotted this line of 4 straight lights across the planet that I assume are satellites.” That is correct! Binoculars or a small telescope will show Jupiter’s moons.

View at EarthSky Community Photos. | Cathy Adams in St. Stephen, New Brunswick, Canada, captured 2 of Jupiter’s moons and giant Jupiter itself on September 3, 2022. Cathy wrote: “After so many cloudy nights I was fortunate to get a beautiful clear one! And it was absolutely wonderful to enjoy a night out observing, and imaging our neighboring planets!!” Thank you, Cathy!

View at EarthSky Community Photos. | Around the time of its yearly opposition, Jupiter is brightest in our sky, best through a telescope, and visible all night. Michael Terhune in Lunenburg, Massachusetts, captured Jupiter in August 2021. He wrote: “My sharpest image of Jupiter! Showing 2 of its Galilean satellites, Io and Europa. The Great Red Spot is also visible.” Thank you, Michael.

More images

View at EarthSky Community Photos. | Meiying Lee in Taipei, Taiwan, took these images of Jupiter’s 4 largest moons over the course of a single night. She wrote: “I always thought that to see obvious changes in the 4 major satellites of Jupiter would take several nights of continuous observation. Later, I discovered that the Galilean satellites move very fast around Jupiter.” See the volcanic moon Io move behind Jupiter and emerge on the other side just a few hours later? Amazing! Thanks, Meiying.

Meiying Lee in Taipei, Taiwan, shared this chart with us on October 6, 2023, and wrote: “From the evening of August 15 to the early morning of August 16, 2021, the Galilean satellites experienced very exciting changes. Callisto, Ganymede, and Europa passed through the surface of Jupiter one after another, while Io was occulted by Jupiter. This resulted in the rare phenomenon that there were no Galilean satellites around Jupiter for 20 minutes late at night on August 16th. Finally, before dawn, the 4 satellites appeared around Jupiter one after another. I watched the Galilean satellites show all night, it was really exciting!” Thank you, Meiying.

View at EarthSky Community Photos. | Sona Shahani Shukla in New Delhi, India, caught a transit of the innermost Galilean moon, Io, across the face of Jupiter on July 7, 2021, and wrote: “Io appears to be skimming Jupiter’s cloud tops, but it’s actually 310,000 miles (500,000 km) from Jupiter. Io zips around Jupiter in 1.8 days, whereas our moon circles Earth every 28 days. The conspicuous black spot on Jupiter is Io’s shadow and is about the size of the moon itself (2,262 miles or 3,640 km across). This shadow sails across the face of Jupiter at 38,000 mph (17 km per second).” Thank you, Sona!

Special viewings of Jupiter’s moons

As with most moons and planets, the Galilean moons orbit Jupiter around its equator. We do see their orbits almost exactly edge-on, but, as with so much in astronomy, there’s a cycle for viewing the edge-on-ness of Jupiter’s moons. This particular cycle is six years long. So every six years we view Jupiter’s equator – and the moons orbiting above its equator – at the most edge-on. During these special times, we can see the moons eclipse and cast shadows on not just giant Jupiter but on each other.

In 2021 we were able to view a number of mutual events (eclipses and shadow transits) involving Jupiter’s moons. The next cycle of mutual events will be in 2027.

Another special event, a rare triple transit, occurs on October 18, 2025, when three of Jupiter’s moons will pass in front of the giant planet at once. The last time Earth could witness a triple transit was in 2021. Triple transits are not visible from all parts of the globe, however.

You can find information here for dates and times to observe the Galilean moons

Composite image of Jupiter and its 4 Galilean moons. From left to right the moons are Io, Europa, Ganymede and Callisto. The Galileo spacecraft obtained the images to make this composite in 1996. Image via NASA Photojournal.

Jupiter at opposition in December 2024

On December 7, 2024, Jupiter is at opposition, when the planet is opposite the sun in the sky as seen from Earth. When Earth passes directly between Jupiter and the sun, we’ll see Jupiter rise at sunset and set at sunrise. Opposition is the middle of the best time of the year to see a planet, since that’s when the planet is up and viewable all night and is generally closest for the year. But any time Jupiter is visible in your sky, you can view Jupiter’s four major moons.

So if you get a chance, grab some binoculars or a small telescope and go see Jupiter’s Galilean moons with your own eyes!

Click here for recommended sky almanacs; they can tell you Jupiter’s rising time in your sky.

Opposition – when Earth is directly between Jupiter and the sun – is the best time to observe the largest planet and its 4 Galilean moons. In 2024, Jupiter’s opposition is December 7. Image via EarthSky.

Bottom line: November and December 2024 are great months for seeing Jupiter’s moons Io, Europa, Ganymede and Callisto with binoculars or a small telescope.

Check here for dates and times to observe the Great Red Spot

The post Jupiter’s moons: How to see and enjoy them first appeared on EarthSky.

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Final Parker Solar Probe flyby of Venus today

The Parker Solar Probe has been studying the sun since its launch in 2018. The mission has used a series of 7 flybys of Venus to get it in the proper positions. This view of Venus is from the July 2020 Venus flyby. It shows the closest planet to Earth with streaking cosmic rays, dust and background stars. The final Parker Solar Probe flyby of Venus is today, November 6, 2024. Image via NASA.

• Parker Solar Probe is a mission to study the sun. In 2021 it became the first spacecraft to “touch” the sun, when it flew though our sun’s wispy atmosphere.
• Parker will flyby Venus today, November 6, 2024, in order to get it into position for its final studies of the sun.
• The flyby will also allow Parker to see Venus’ surface, even through the thick cloud cover. Previous flybys have shown differences in the Venusian surface from the Magellan mission in the 1990s.

Miles Hatfield wrote this original article for NASA on November 4, 2024. Edits by EarthSky.

Join the 2025 Lunar Calendar presale today to snag a copy signed by the visionary Deborah Byrd herself.

Final Parker Solar Probe flyby of Venus

Today, November 6, 2024, NASA’s Parker Solar Probe will complete its final Venus gravity assist maneuver, passing within 233 miles (375 km) of Venus’ surface. The flyby will adjust Parker’s trajectory into its final orbital configuration, bringing the spacecraft to within an unprecedented 3.8 million miles (6.2 million km) of the solar surface on December 24, 2024. It will be the closest any human-made object has been to the sun.

Parker’s Venus flybys have become boons for new Venus science, thanks to a chance discovery from its Wide-Field Imager for Parker Solar Probe, or WISPR. The instrument peers out from Parker and away from the sun to see fine details in the solar wind. But on July 11, 2020, during Parker’s third Venus flyby, scientists turned WISPR toward Venus in hopes of tracking changes in the planet’s thick cloud cover. The images revealed a surprise: A portion of WISPR’s data, which captures visible and near infrared light, seemed to see all the way through the clouds to the Venusian surface below.

Noam Izenberg, a space scientist at the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland, said:

The WISPR cameras can see through the clouds to the surface of Venus, which glows in the near-infrared because it’s so hot.

Venus, sizzling at approximately 869 degrees Fahrenheit (about 465 C), was radiating through the clouds.

The WISPR images from the 2020 flyby, as well as the next flyby in 2021, revealed Venus’ surface in a new light. But they also raised puzzling questions, and scientists have devised the November 6 flyby to help answer them.

Seeing Venus’ surface

The Venus images correspond well with data from the Magellan spacecraft. The images show dark and light patterns that line up with surface regions Magellan captured when it mapped Venus’ surface using radar from 1990 to 1994. Yet some parts of the WISPR images appear brighter than expected, hinting at extra information captured by WISPR’s data. Is WISPR picking up on chemical differences on the surface, where the ground is made of different material? Perhaps it’s seeing variations in age, where more recent lava flows added a fresh coat to the Venusian surface.

Izenberg said:

Because it flies over a number of similar and different landforms than the previous Venus flybys, the November 6 flyby will give us more context to evaluate whether WISPR can help us distinguish physical or even chemical properties of Venus’ surface.

WISPR images from the Parker Solar Probe show the surface of Venus with features in the same places where the Magellan mission from the 1990s revealed topography with its radar. However, some parts of the WISPR images appear brighter than expected. The November 6 flyby will offer more details. Image via NASA.

Next up: Parker’s final explorations of the sun

After the November 6 flyby, Parker will be on course to swoop within 3.8 million miles (6.2 million km) of the solar surface, the final objective of the historic mission first conceived over 65 years ago. No human-made object has ever passed this close to a star, so Parker’s data will be charting as-yet uncharted territory. In this hyper-close regime, Parker will cut through plumes of plasma still connected to the sun. It is close enough to pass inside a solar eruption, like a surfer diving under a crashing ocean wave.

Adam Szabo, project scientist for Parker Solar Probe at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, said:

This is a major engineering accomplishment.

The closest approach to the sun, or perihelion, will occur on December 24, 2024. At that time, mission control will be out of contact with the spacecraft. Parker will send a beacon tone on December 27, 2024, to confirm its success and the spacecraft’s health. Parker will remain in this orbit for the remainder of its mission, completing two more perihelia at the same distance.

Bottom line: The final Parker Solar Probe flyby of Venus happens on November 6, 2024. Previous flybys of Venus have shown surface features beneath the planet’s thick clouds. What will the final flyby reveal?

Via NASA

Read more: Parker Solar Probe: 1st spacecraft to touch sun

Read more: Parker Solar Probe captures a glimpse of Venus

The post Final Parker Solar Probe flyby of Venus today first appeared on EarthSky.

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The Parker Solar Probe has been studying the sun since its launch in 2018. The mission has used a series of 7 flybys of Venus to get it in the proper positions. This view of Venus is from the July 2020 Venus flyby. It shows the closest planet to Earth with streaking cosmic rays, dust and background stars. The final Parker Solar Probe flyby of Venus is today, November 6, 2024. Image via NASA.

• Parker Solar Probe is a mission to study the sun. In 2021 it became the first spacecraft to “touch” the sun, when it flew though our sun’s wispy atmosphere.
• Parker will flyby Venus today, November 6, 2024, in order to get it into position for its final studies of the sun.
• The flyby will also allow Parker to see Venus’ surface, even through the thick cloud cover. Previous flybys have shown differences in the Venusian surface from the Magellan mission in the 1990s.

Miles Hatfield wrote this original article for NASA on November 4, 2024. Edits by EarthSky.

Join the 2025 Lunar Calendar presale today to snag a copy signed by the visionary Deborah Byrd herself.

Final Parker Solar Probe flyby of Venus

Today, November 6, 2024, NASA’s Parker Solar Probe will complete its final Venus gravity assist maneuver, passing within 233 miles (375 km) of Venus’ surface. The flyby will adjust Parker’s trajectory into its final orbital configuration, bringing the spacecraft to within an unprecedented 3.8 million miles (6.2 million km) of the solar surface on December 24, 2024. It will be the closest any human-made object has been to the sun.

Parker’s Venus flybys have become boons for new Venus science, thanks to a chance discovery from its Wide-Field Imager for Parker Solar Probe, or WISPR. The instrument peers out from Parker and away from the sun to see fine details in the solar wind. But on July 11, 2020, during Parker’s third Venus flyby, scientists turned WISPR toward Venus in hopes of tracking changes in the planet’s thick cloud cover. The images revealed a surprise: A portion of WISPR’s data, which captures visible and near infrared light, seemed to see all the way through the clouds to the Venusian surface below.

Noam Izenberg, a space scientist at the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland, said:

The WISPR cameras can see through the clouds to the surface of Venus, which glows in the near-infrared because it’s so hot.

Venus, sizzling at approximately 869 degrees Fahrenheit (about 465 C), was radiating through the clouds.

The WISPR images from the 2020 flyby, as well as the next flyby in 2021, revealed Venus’ surface in a new light. But they also raised puzzling questions, and scientists have devised the November 6 flyby to help answer them.

Seeing Venus’ surface

The Venus images correspond well with data from the Magellan spacecraft. The images show dark and light patterns that line up with surface regions Magellan captured when it mapped Venus’ surface using radar from 1990 to 1994. Yet some parts of the WISPR images appear brighter than expected, hinting at extra information captured by WISPR’s data. Is WISPR picking up on chemical differences on the surface, where the ground is made of different material? Perhaps it’s seeing variations in age, where more recent lava flows added a fresh coat to the Venusian surface.

Izenberg said:

Because it flies over a number of similar and different landforms than the previous Venus flybys, the November 6 flyby will give us more context to evaluate whether WISPR can help us distinguish physical or even chemical properties of Venus’ surface.

WISPR images from the Parker Solar Probe show the surface of Venus with features in the same places where the Magellan mission from the 1990s revealed topography with its radar. However, some parts of the WISPR images appear brighter than expected. The November 6 flyby will offer more details. Image via NASA.

Next up: Parker’s final explorations of the sun

After the November 6 flyby, Parker will be on course to swoop within 3.8 million miles (6.2 million km) of the solar surface, the final objective of the historic mission first conceived over 65 years ago. No human-made object has ever passed this close to a star, so Parker’s data will be charting as-yet uncharted territory. In this hyper-close regime, Parker will cut through plumes of plasma still connected to the sun. It is close enough to pass inside a solar eruption, like a surfer diving under a crashing ocean wave.

Adam Szabo, project scientist for Parker Solar Probe at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, said:

This is a major engineering accomplishment.

The closest approach to the sun, or perihelion, will occur on December 24, 2024. At that time, mission control will be out of contact with the spacecraft. Parker will send a beacon tone on December 27, 2024, to confirm its success and the spacecraft’s health. Parker will remain in this orbit for the remainder of its mission, completing two more perihelia at the same distance.

Bottom line: The final Parker Solar Probe flyby of Venus happens on November 6, 2024. Previous flybys of Venus have shown surface features beneath the planet’s thick clouds. What will the final flyby reveal?

Via NASA

Read more: Parker Solar Probe: 1st spacecraft to touch sun

Read more: Parker Solar Probe captures a glimpse of Venus

The post Final Parker Solar Probe flyby of Venus today first appeared on EarthSky.

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First 3D view of globular cluster formation and evolution

Scientists analyzed the motion of how stars move inside these 16 globular clusters that orbit our Milky Way galaxy. The result was the first 3D view of globular cluster formation and evolution. Image via ESA/ Hubble/ ESO/ SDSS/ INAF.

First 3D view of globular cluster formation and evolution

Globular clusters are giant balls of millions of stars held together by gravity and orbiting in the halo of our Milky Way galaxy. On November 5, 2024, scientists from the National Institute for Astrophysics (INAF), the University of Bologna and Indiana University said they’ve conducted the first 3D analysis of how stars move within 16 globular clusters. Their study adds to the understanding of the formation and evolution of these massive stellar groups.

The scientists published their study in the peer-reviewed journal Astronomy & Astrophysics on November 5, 2024.

Lead author Emanuele Dalessandro of INAF said:

Understanding the physical processes behind the formation and early evolution of globular clusters is one of the most fascinating and debated astrophysical questions of the past 20 to 25 years. The results of our study provide the first solid evidence that globular clusters formed through multiple star formation events. And it places fundamental constraints on the dynamical path followed by the clusters throughout their evolution. These results were possible thanks to a multi-diagnostic approach and the combination of state-of-the-art observations and dynamic simulations.

Understanding globular clusters

Globular clusters contain the most ancient stars in our Milky Way. They can be 12 to 13 billion years old. And stars in globular clusters probably formed first, as our galaxy was forming. But globular clusters aren’t just residents of our galaxy. We’ve seen them even in distant galaxies. In fact, globular clusters were probably some of the first systems to evolve as the universe began. But how they came to be is still a mystery.

Dalessandro said:

Their astrophysical significance is huge because they not only help us to test cosmological models of the formation of the universe due to their age but also provide natural laboratories for studying the formation, evolution and chemical enrichment of galaxies.

Co-author Mario Cadelano of the University of Bologna and INAF associate added:

Results obtained in the last two decades have unexpectedly shown that globular clusters consist of more than one stellar population: a primordial one, with chemical properties similar to other stars in the galaxy, and another with anomalous chemical abundances of light elements such as helium, oxygen, sodium and nitrogen. Despite the large number of observations and theoretical models aimed at characterizing these populations, the mechanisms regulating their formation are still not understood.

ESA’s Gaia mapping the stars of the Milky Way. Image via ESA/ ATG medialab. Background ESO/ S. Brunier.

Obtaining the 3D view of globular cluster motions

The scientists looked at the proper motion of stars in globular clusters, along with their radial velocities. To do so, they used data from telescopes such as ESA’s Gaia and ESO’s VLT. Co-author Alessandro Della Croce of INAF said:

In this work, we analyzed in detail the motion of thousands of stars within each cluster. It quickly became clear that stars belonging to different populations have distinct kinematic properties [or movements]: stars with anomalous chemical composition tend to rotate faster than the others within the cluster and progressively spread from the central regions to the outer ones.

Croce added:

These results are consistent with the long-term dynamical evolution of stellar systems, in which stars with anomalous chemical abundances form more centrally concentrated and rotate more rapidly than the standard ones. This, in turn, suggests that globular clusters formed through multiple star formation episodes and provides an important piece of information in defining the physical processes and timescales underlying the formation and evolution of massive stellar clusters.

These new insights help astronomers better understand how these ancient globular clusters formed and evolved and fit into the history of our galaxy and the wider universe.

The ESO Very Large Telescope (VLT) during observations. Image via ESO/ S. Brunier.

Bottom line: For the first time, astronomers have analyzed a 3D view of globular cluster formation and evolution by tracking the motions of the star systems within.

Source: A 3D view of multiple populations kinematics in Galactic globular clusters

Via INAF

The post First 3D view of globular cluster formation and evolution first appeared on EarthSky.

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Scientists analyzed the motion of how stars move inside these 16 globular clusters that orbit our Milky Way galaxy. The result was the first 3D view of globular cluster formation and evolution. Image via ESA/ Hubble/ ESO/ SDSS/ INAF.

First 3D view of globular cluster formation and evolution

Globular clusters are giant balls of millions of stars held together by gravity and orbiting in the halo of our Milky Way galaxy. On November 5, 2024, scientists from the National Institute for Astrophysics (INAF), the University of Bologna and Indiana University said they’ve conducted the first 3D analysis of how stars move within 16 globular clusters. Their study adds to the understanding of the formation and evolution of these massive stellar groups.

The scientists published their study in the peer-reviewed journal Astronomy & Astrophysics on November 5, 2024.

Lead author Emanuele Dalessandro of INAF said:

Understanding the physical processes behind the formation and early evolution of globular clusters is one of the most fascinating and debated astrophysical questions of the past 20 to 25 years. The results of our study provide the first solid evidence that globular clusters formed through multiple star formation events. And it places fundamental constraints on the dynamical path followed by the clusters throughout their evolution. These results were possible thanks to a multi-diagnostic approach and the combination of state-of-the-art observations and dynamic simulations.

Understanding globular clusters

Globular clusters contain the most ancient stars in our Milky Way. They can be 12 to 13 billion years old. And stars in globular clusters probably formed first, as our galaxy was forming. But globular clusters aren’t just residents of our galaxy. We’ve seen them even in distant galaxies. In fact, globular clusters were probably some of the first systems to evolve as the universe began. But how they came to be is still a mystery.

Dalessandro said:

Their astrophysical significance is huge because they not only help us to test cosmological models of the formation of the universe due to their age but also provide natural laboratories for studying the formation, evolution and chemical enrichment of galaxies.

Co-author Mario Cadelano of the University of Bologna and INAF associate added:

Results obtained in the last two decades have unexpectedly shown that globular clusters consist of more than one stellar population: a primordial one, with chemical properties similar to other stars in the galaxy, and another with anomalous chemical abundances of light elements such as helium, oxygen, sodium and nitrogen. Despite the large number of observations and theoretical models aimed at characterizing these populations, the mechanisms regulating their formation are still not understood.

ESA’s Gaia mapping the stars of the Milky Way. Image via ESA/ ATG medialab. Background ESO/ S. Brunier.

Obtaining the 3D view of globular cluster motions

The scientists looked at the proper motion of stars in globular clusters, along with their radial velocities. To do so, they used data from telescopes such as ESA’s Gaia and ESO’s VLT. Co-author Alessandro Della Croce of INAF said:

In this work, we analyzed in detail the motion of thousands of stars within each cluster. It quickly became clear that stars belonging to different populations have distinct kinematic properties [or movements]: stars with anomalous chemical composition tend to rotate faster than the others within the cluster and progressively spread from the central regions to the outer ones.

Croce added:

These results are consistent with the long-term dynamical evolution of stellar systems, in which stars with anomalous chemical abundances form more centrally concentrated and rotate more rapidly than the standard ones. This, in turn, suggests that globular clusters formed through multiple star formation episodes and provides an important piece of information in defining the physical processes and timescales underlying the formation and evolution of massive stellar clusters.

These new insights help astronomers better understand how these ancient globular clusters formed and evolved and fit into the history of our galaxy and the wider universe.

The ESO Very Large Telescope (VLT) during observations. Image via ESO/ S. Brunier.

Bottom line: For the first time, astronomers have analyzed a 3D view of globular cluster formation and evolution by tracking the motions of the star systems within.

Source: A 3D view of multiple populations kinematics in Galactic globular clusters

Via INAF

The post First 3D view of globular cluster formation and evolution first appeared on EarthSky.

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Could we find dark matter in clouds around neutron stars?

Artist’s concept of dark matter, as if we could easily see it. A new study says we might be able to see dark matter in the form of axions – hypothetical subatomic particles – clouding around neutron stars. Image via United States Department of Energy/ Wikimedia Commons (public domain).

The 2025 EarthSky Lunar Calendar presale is here! First 100 purchases signed by the legendary Deborah Byrd as a thank you. Get yours today!

Looking for dark matter

It’s thought that around 85% of all matter in the universe is dark matter. We can’t see this mysterious substance, or detect it with any currently known method … but we think it exists because we can measure its gravitational effects on normal matter. A leading theory says that dark matter could be composed of axions: hypothetical subatomic particles that have not yet been detected.

On October 17, 2024, a team of physicists from the universities of Amsterdam, Princeton and Oxford said that axions should form dense clouds around neutron stars. And if so, we might be able to observe these dark matter candidates through today’s telescopes.

In October 2023, the same researchers theorized that it’s possible to detect axions that have escaped from a neutron star. Now, their followup study focuses on the axions that wouldn’t be able to escape the star’s gravity. They published their peer-reviewed findings in the journal Physical Review X on October 17, 2024.

A hypothetical axion cloud around a neutron star. The team’s previous study focused on the axions leaving the neutron star, but now they’re considering the axions that would be stuck within the star’s intense magnetic field. Image via D. Noordhuis et al./ University of Amsterdam.

Dark matter: A missing piece

When faced with a gap in our theories about how the universe works, physicists sometimes come up with something entirely new to fill the hole. In the early 20th century, various astronomers found that the universe must contain more mass than we can see. And in the 1960s, astronomer Vera Rubin discovered that galaxies rotate so fast their mass shouldn’t prevent them from flying apart.

The only way to explain these discrepancies was to hypothesize the existence of a new, unseen form of matter: dark matter. This unknown and strange substance has not yet been found, but if it is discovered, it would solve a long list of problems.

In the 1970s, scientists came up with axions to explain an inconsistency in the way neutrons should function according to the Standard Model of particle physics. The Standard Model is our best guess at how the universe works at a fundamental level, but it’s not perfect. And the existence of axions would help clean up one of its mysteries, which is why they were named after a brand of soap!

Another intriguing thing about axions is that they might also solve the conundrum of what is dark matter. Dark matter is seemingly invisible because it doesn’t interact with light or matter. But there’s a chance it does interact with axions, just incredibly weakly. And axions also seem to be invisible and would also interact incredibly weakly with other particles. Coincidence? Some scientists think not. So they believe axions could be an explanation for dark matter.

Observing axions

If axions do exist, how can scientists observe them? The solution, according to the researchers, lies with neutron stars.

Neutron stars are some of the most bizarre phenomena in the known universe. They’re the small, super-dense objects left over when massive stars explode as supernovae and their cores collapse. They typically have about 1.4 times our sun’s mass that’s squeezed into a sphere roughly 12-25 miles (20-40 kilometers) across. So they’re incredibly dense. In fact, a teaspoon of neutron star material weighs more than Mount Everest.

When a star’s core collapses down to form a neutron star, its magnetic field lines compress. That makes its magnetism stronger. A neutron star’s magnetic field is one of the strongest in the universe, billions of times stronger than any on Earth.

That’s important, because scientists believe axions should transform into light particles when exposed to a strong-enough magnetic field. The amount of light that a single axion could produce would barely register. But a huge amount of axions – in contact with a hugely powerful magnetic field – should produce enough light that today’s radio telescopes could see it.

This illustration compares the size of a neutron star to Manhattan Island in New York, which is about 13 miles (21 km) long. Image via NASA/ Goddard Space Flight Center.

Clouds of dark matter?

And it turns out neutron stars could produce a lot of axions. In their original October 2023 study, the researchers found that pulsars – rapidly spinning neutron stars – could produce a 50-digit number of axions every second. They went on to explore the possibility of detecting some of these axions as they escape the neutron star.

Their new study focuses on the axions that stay behind. This idea relies on another extreme property of neutron stars: their immense gravity. As you might expect given their density, neutron stars have an incredibly strong gravitational pull. And, since axions interact with gravity, that makes neutron stars excellent axion traps.

For the same reason, black holes are also thought to collect huge numbers of axions. But the gravity of black holes is so much that they would also absorb what they capture. Neutron stars are thought to have just the right gravitational force to capture and hold axions around them. And since axions interact very weakly with other particles, the researchers think they would simply accumulate around the neutron star. Over millions of years, they would theoretically form a dense cloud, providing the perfect opportunity for scientists to detect them.

Making the detection

There are two main ways that scientists could detect light from axion clouds. It could be visible as a continuous signal emitted during much of a neutron star’s lifetime. Or it could appear as a one-time burst of light at the end of the neutron star’s life.

Importantly, the researchers said that axion clouds would be generic and should theoretically occur around any neutron star.

So far, axion clouds have not been observed. But the researchers now know what they’re looking for. And if they find direct evidence of axions, it will be a major step in answering several of physics’ biggest problems.

Bottom line: Researchers say that we might be able to detect dark matter clouding around neutron stars in the form of axions, a hypothetical subatomic particle.

Source: Axion Clouds around Neutron Stars

Via University of Amsterdam

Read more: Can we detect dark matter using light from pulsars?

Dark matter black holes could make Mars wobble

The post Could we find dark matter in clouds around neutron stars? first appeared on EarthSky.

from EarthSky https://ift.tt/WJgdUc4

Artist’s concept of dark matter, as if we could easily see it. A new study says we might be able to see dark matter in the form of axions – hypothetical subatomic particles – clouding around neutron stars. Image via United States Department of Energy/ Wikimedia Commons (public domain).

The 2025 EarthSky Lunar Calendar presale is here! First 100 purchases signed by the legendary Deborah Byrd as a thank you. Get yours today!

Looking for dark matter

It’s thought that around 85% of all matter in the universe is dark matter. We can’t see this mysterious substance, or detect it with any currently known method … but we think it exists because we can measure its gravitational effects on normal matter. A leading theory says that dark matter could be composed of axions: hypothetical subatomic particles that have not yet been detected.

On October 17, 2024, a team of physicists from the universities of Amsterdam, Princeton and Oxford said that axions should form dense clouds around neutron stars. And if so, we might be able to observe these dark matter candidates through today’s telescopes.

In October 2023, the same researchers theorized that it’s possible to detect axions that have escaped from a neutron star. Now, their followup study focuses on the axions that wouldn’t be able to escape the star’s gravity. They published their peer-reviewed findings in the journal Physical Review X on October 17, 2024.

A hypothetical axion cloud around a neutron star. The team’s previous study focused on the axions leaving the neutron star, but now they’re considering the axions that would be stuck within the star’s intense magnetic field. Image via D. Noordhuis et al./ University of Amsterdam.

Dark matter: A missing piece

When faced with a gap in our theories about how the universe works, physicists sometimes come up with something entirely new to fill the hole. In the early 20th century, various astronomers found that the universe must contain more mass than we can see. And in the 1960s, astronomer Vera Rubin discovered that galaxies rotate so fast their mass shouldn’t prevent them from flying apart.

The only way to explain these discrepancies was to hypothesize the existence of a new, unseen form of matter: dark matter. This unknown and strange substance has not yet been found, but if it is discovered, it would solve a long list of problems.

In the 1970s, scientists came up with axions to explain an inconsistency in the way neutrons should function according to the Standard Model of particle physics. The Standard Model is our best guess at how the universe works at a fundamental level, but it’s not perfect. And the existence of axions would help clean up one of its mysteries, which is why they were named after a brand of soap!

Another intriguing thing about axions is that they might also solve the conundrum of what is dark matter. Dark matter is seemingly invisible because it doesn’t interact with light or matter. But there’s a chance it does interact with axions, just incredibly weakly. And axions also seem to be invisible and would also interact incredibly weakly with other particles. Coincidence? Some scientists think not. So they believe axions could be an explanation for dark matter.

Observing axions

If axions do exist, how can scientists observe them? The solution, according to the researchers, lies with neutron stars.

Neutron stars are some of the most bizarre phenomena in the known universe. They’re the small, super-dense objects left over when massive stars explode as supernovae and their cores collapse. They typically have about 1.4 times our sun’s mass that’s squeezed into a sphere roughly 12-25 miles (20-40 kilometers) across. So they’re incredibly dense. In fact, a teaspoon of neutron star material weighs more than Mount Everest.

When a star’s core collapses down to form a neutron star, its magnetic field lines compress. That makes its magnetism stronger. A neutron star’s magnetic field is one of the strongest in the universe, billions of times stronger than any on Earth.

That’s important, because scientists believe axions should transform into light particles when exposed to a strong-enough magnetic field. The amount of light that a single axion could produce would barely register. But a huge amount of axions – in contact with a hugely powerful magnetic field – should produce enough light that today’s radio telescopes could see it.

This illustration compares the size of a neutron star to Manhattan Island in New York, which is about 13 miles (21 km) long. Image via NASA/ Goddard Space Flight Center.

Clouds of dark matter?

And it turns out neutron stars could produce a lot of axions. In their original October 2023 study, the researchers found that pulsars – rapidly spinning neutron stars – could produce a 50-digit number of axions every second. They went on to explore the possibility of detecting some of these axions as they escape the neutron star.

Their new study focuses on the axions that stay behind. This idea relies on another extreme property of neutron stars: their immense gravity. As you might expect given their density, neutron stars have an incredibly strong gravitational pull. And, since axions interact with gravity, that makes neutron stars excellent axion traps.

For the same reason, black holes are also thought to collect huge numbers of axions. But the gravity of black holes is so much that they would also absorb what they capture. Neutron stars are thought to have just the right gravitational force to capture and hold axions around them. And since axions interact very weakly with other particles, the researchers think they would simply accumulate around the neutron star. Over millions of years, they would theoretically form a dense cloud, providing the perfect opportunity for scientists to detect them.

Making the detection

There are two main ways that scientists could detect light from axion clouds. It could be visible as a continuous signal emitted during much of a neutron star’s lifetime. Or it could appear as a one-time burst of light at the end of the neutron star’s life.

Importantly, the researchers said that axion clouds would be generic and should theoretically occur around any neutron star.

So far, axion clouds have not been observed. But the researchers now know what they’re looking for. And if they find direct evidence of axions, it will be a major step in answering several of physics’ biggest problems.

Bottom line: Researchers say that we might be able to detect dark matter clouding around neutron stars in the form of axions, a hypothetical subatomic particle.

Source: Axion Clouds around Neutron Stars

Via University of Amsterdam

Read more: Can we detect dark matter using light from pulsars?

Dark matter black holes could make Mars wobble

The post Could we find dark matter in clouds around neutron stars? first appeared on EarthSky.

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Open star clusters are loose groups of stars

View at EarthSky Community Photos. | Jeremy Likness in Newport, Oregon, captured the Pleiades star cluster on January 16, 2024. Jeremy wrote: “Can’t get enough of these winter sapphires.” Thank you, Jeremy! Reflection nebulae around the hot blue luminous stars of the Pleiades give them an eerie and spectacular glow. Read more about open star clusters below.

The 2025 EarthSky Lunar Calendar presale is here! First 100 purchases signed by the legendary Deborah Byrd as a thank you. Get yours today!

Open star clusters

Open star clusters are young, loosely bound gatherings of stars. The stars in these clusters were born together. They’re still sometimes moving within the nebula, or cosmic cloud, of their creation. They’re occasionally called galactic clusters. Scientists have discovered more than 1,100 open clusters around us in space. They may contain a handful of stars or thousands of stars. Most likely won’t survive more than several orbits around our galaxy’s center before being disrupted and dispersed. You can see many open star clusters with the eye alone! Or you can aim binoculars or telescopes their way …

Pleiades is a gem among open star clusters

The Pleiades cluster (M45) is a wonderful open cluster in the constellation Taurus the Bull. A favorite observing target, the Pleiades stands out to the eye alone as a fuzzy patch that resembles a tiny dipper. About six stars are visible with the unaided eye. Through binoculars, the view explodes into dozens of stars.

The Pleiades – aka the Seven Sisters – may have dimmed enough since its naming, because only six stars are now readily visible. The word Pleiades translates to Subaru in Japanese, and you might recognize the grouping of six stars from the car-maker’s logo. The stars in the Pleiades were born together about 100 million years ago. And the open cluster itself lies about 440 light-years away.

What about globular star clusters?

By the way, open star clusters are not to be confused with tightly bound globular star clusters. Globular clusters are ancient and far away, orbiting in the halo of the Milky Way. In fact, globular clusters formed about 13 billion years, when the Milky Way was forming. In contrast, open clusters are typically only millions of years old.

One of the best-known globular clusters seen from the Northern Hemisphere is the Great Cluster in Hercules (M13). It’s about 25,000 light-years away. Contrast the M13’s large distance to that of the relatively nearby Pleiades (444 light-years).

Read more: The Pleiades or 7 Sisters

Not an open cluster. View at EarthSky Community Photos. | Mario Rana in Hampton, Virginia, captured globular cluster M13 on June 10, 2023. He wrote: “Globular cluster M13 in the constellation Hercules. The object at the bottom left corner is spiral galaxy NGC 6207.” Thank you, Mario!

Distance to open star clusters makes a difference

The distance to a star cluster will affect its appearance to us on Earth. Open star clusters are recognizable as a concentration of stars in one area of the sky. These conglomerations of light – such as the Pleiades or the Wild Duck Cluster (M11) – are obvious to telescope and binocular users. Many are obvious through binoculars when you are skimming along the Milky Way.

But what about star clusters that are closer to Earth?

Some Big Dipper stars are members of an open cluster

The familiar Big Dipper asterism is part of an open cluster. These stars are all about 80 light-years away and belong to a loosely assembled open star cluster known as the Ursa Major Moving Group. The Big Dipper is an example of a cluster that’s so close that it wasn’t immediately identifiable as a cluster. First, astronomers had to learn about the motions of stars in various parts of the sky. Then, they understood the Ursa Major Moving Group was an open cluster.

The Big Dipper, just like other open clusters, will grow apart as it ages. Alkaid and Dubhe, two stars in the Big Dipper, are not part of the Ursa Major Moving Group. Those two stars will stretch away from the rest and the dipper shape will become obscured, forming a new shape, just as many thousands of years ago the stars looked more like a kite with a long tail than its current dipper shape.

View at EarthSky Community Photos. | Some of the stars of the Big Dipper are part of an open cluster called the Ursa Major Moving Group. Susan Jensen captured this image on September 6, 2024, and wrote: “Right place, right time! Standing on a gravel road in the middle of nowhere, looking across a stubble field. This slow-moving, vibrant meteor stopped me in my tracks! I was shooting the Big Dipper with the shutter locked to catch multiple frames for stacking when this monster did a slow flyby. How lucky that I was able to capture it!” Thank you, Susan!

Watch how the Big Dipper changes over time

Hyades is another star cluster in Taurus

The V-shaped Hyades star cluster in the constellation Taurus the Bull is another excellent open cluster to target with the eye alone. The Hyades is so large you could not hope to capture the entire cluster within the field of view of binoculars or a telescope. Instead, binocular and telescope-users examine the cluster bit by bit.

The Hyades marks the head of Taurus the Bull. It is a large open star cluster in the shape of the letter V and is visible during northern winter (southern summer). This open star cluster is a group of 300 to 400 stars that lie about 151 light-years away from us, thus making it one of the nearest open clusters to Earth. With the unaided eye under moderately good seeing conditions, an observer should be able to see five stars that mark the two sides and juncture of the V.

The stars of Hyades

The five brightest stars in the Hyades are all red giants, but you’ll notice one shines much more brightly than the others. The brightest star in Hyades – and in the constellation Taurus – is Aldebaran. Aldebaran marks the top left side of the bull’s head. If Aldebaran is also a red giant star, why does it look so much brighter than the rest of the group? The reason is that it’s not a member of the Hyades cluster. It just happens to lie in the same line of sight. At 65 light-years distant, Aldebaran is 2 1/2 times closer than the rest of the cluster.

The Hyades open star cluster forms the V-shaped face of the Bull in Taurus. The bright red star Aldebaran isn’t a true cluster member. Another open star cluster, the Pleiades, is nearby. Image via EarthSky.

The busy Beehive cluster

The Beehive star cluster is another famous example of an easy-to-see open star cluster. The Beehive lies at the center of the constellation Cancer the Crab and is also known by the names M44 or Praesepe, which is Latin for manger.

At magnitude 3.7, the Beehive Cluster can be tricky to spot from a light-polluted area because of how diffuse it is; it’s spread out more than twice the size of a full moon. Using only your eyes, the open cluster will appear as a misty patch of light. Binoculars will help you focus in on a handful of stars. If you’re using a telescope, make sure to use a low-power eyepiece because the stars will spill out of your field of view.

Astronomers have found that the Beehive Cluster contains at least 1,000 stars, but only a fraction of them are visible with amateur equipment. By the way, Galileo saw 40 with his rudimentary telescope. Also, at least two planets are now known to be orbiting stars in the Beehive Cluster.

The cluster is about 730 million years old and lies approximately 577 light-years away from us. The Beehive’s age and direction of proper motion through space are similar to the Hyades cluster. This suggests that these two clusters probably had a common origin in a nebula that existed 800 million years ago.

The Beehive finder chart

Look for the Beehive open star cluster between the 2 brightest stars of the constellation Gemini the Twins, Castor and Pollux, and the star Regulus in the constellation Leo. Image via EarthSky.

View at EarthSky Community Photos. | David Hoskin in Halifax, Nova Scotia, Canada, captured the star cluster Messier 44 in the constellation Cancer on December 9, 2023. David wrote: “The Beehive is an open star cluster in the constellation Cancer. It consists of about 1,000 stars and is one of the nearest open clusters to Earth.” Thank you, David!

Bottom line: Open clusters are loosely bound gatherings of stars that may be so young that the nebulae they were born in is still visible. The Pleiades, Hyades, and the Beehive are well-known examples of open clusters.

A different kind of cluster: What’s a globular cluster?

The post Open star clusters are loose groups of stars first appeared on EarthSky.

from EarthSky https://ift.tt/2P4cERf

View at EarthSky Community Photos. | Jeremy Likness in Newport, Oregon, captured the Pleiades star cluster on January 16, 2024. Jeremy wrote: “Can’t get enough of these winter sapphires.” Thank you, Jeremy! Reflection nebulae around the hot blue luminous stars of the Pleiades give them an eerie and spectacular glow. Read more about open star clusters below.

The 2025 EarthSky Lunar Calendar presale is here! First 100 purchases signed by the legendary Deborah Byrd as a thank you. Get yours today!

Open star clusters

Open star clusters are young, loosely bound gatherings of stars. The stars in these clusters were born together. They’re still sometimes moving within the nebula, or cosmic cloud, of their creation. They’re occasionally called galactic clusters. Scientists have discovered more than 1,100 open clusters around us in space. They may contain a handful of stars or thousands of stars. Most likely won’t survive more than several orbits around our galaxy’s center before being disrupted and dispersed. You can see many open star clusters with the eye alone! Or you can aim binoculars or telescopes their way …

Pleiades is a gem among open star clusters

The Pleiades cluster (M45) is a wonderful open cluster in the constellation Taurus the Bull. A favorite observing target, the Pleiades stands out to the eye alone as a fuzzy patch that resembles a tiny dipper. About six stars are visible with the unaided eye. Through binoculars, the view explodes into dozens of stars.

The Pleiades – aka the Seven Sisters – may have dimmed enough since its naming, because only six stars are now readily visible. The word Pleiades translates to Subaru in Japanese, and you might recognize the grouping of six stars from the car-maker’s logo. The stars in the Pleiades were born together about 100 million years ago. And the open cluster itself lies about 440 light-years away.

What about globular star clusters?

By the way, open star clusters are not to be confused with tightly bound globular star clusters. Globular clusters are ancient and far away, orbiting in the halo of the Milky Way. In fact, globular clusters formed about 13 billion years, when the Milky Way was forming. In contrast, open clusters are typically only millions of years old.

One of the best-known globular clusters seen from the Northern Hemisphere is the Great Cluster in Hercules (M13). It’s about 25,000 light-years away. Contrast the M13’s large distance to that of the relatively nearby Pleiades (444 light-years).

Read more: The Pleiades or 7 Sisters

Not an open cluster. View at EarthSky Community Photos. | Mario Rana in Hampton, Virginia, captured globular cluster M13 on June 10, 2023. He wrote: “Globular cluster M13 in the constellation Hercules. The object at the bottom left corner is spiral galaxy NGC 6207.” Thank you, Mario!

Distance to open star clusters makes a difference

The distance to a star cluster will affect its appearance to us on Earth. Open star clusters are recognizable as a concentration of stars in one area of the sky. These conglomerations of light – such as the Pleiades or the Wild Duck Cluster (M11) – are obvious to telescope and binocular users. Many are obvious through binoculars when you are skimming along the Milky Way.

But what about star clusters that are closer to Earth?

Some Big Dipper stars are members of an open cluster

The familiar Big Dipper asterism is part of an open cluster. These stars are all about 80 light-years away and belong to a loosely assembled open star cluster known as the Ursa Major Moving Group. The Big Dipper is an example of a cluster that’s so close that it wasn’t immediately identifiable as a cluster. First, astronomers had to learn about the motions of stars in various parts of the sky. Then, they understood the Ursa Major Moving Group was an open cluster.

The Big Dipper, just like other open clusters, will grow apart as it ages. Alkaid and Dubhe, two stars in the Big Dipper, are not part of the Ursa Major Moving Group. Those two stars will stretch away from the rest and the dipper shape will become obscured, forming a new shape, just as many thousands of years ago the stars looked more like a kite with a long tail than its current dipper shape.

View at EarthSky Community Photos. | Some of the stars of the Big Dipper are part of an open cluster called the Ursa Major Moving Group. Susan Jensen captured this image on September 6, 2024, and wrote: “Right place, right time! Standing on a gravel road in the middle of nowhere, looking across a stubble field. This slow-moving, vibrant meteor stopped me in my tracks! I was shooting the Big Dipper with the shutter locked to catch multiple frames for stacking when this monster did a slow flyby. How lucky that I was able to capture it!” Thank you, Susan!

Watch how the Big Dipper changes over time

Hyades is another star cluster in Taurus

The V-shaped Hyades star cluster in the constellation Taurus the Bull is another excellent open cluster to target with the eye alone. The Hyades is so large you could not hope to capture the entire cluster within the field of view of binoculars or a telescope. Instead, binocular and telescope-users examine the cluster bit by bit.

The Hyades marks the head of Taurus the Bull. It is a large open star cluster in the shape of the letter V and is visible during northern winter (southern summer). This open star cluster is a group of 300 to 400 stars that lie about 151 light-years away from us, thus making it one of the nearest open clusters to Earth. With the unaided eye under moderately good seeing conditions, an observer should be able to see five stars that mark the two sides and juncture of the V.

The stars of Hyades

The five brightest stars in the Hyades are all red giants, but you’ll notice one shines much more brightly than the others. The brightest star in Hyades – and in the constellation Taurus – is Aldebaran. Aldebaran marks the top left side of the bull’s head. If Aldebaran is also a red giant star, why does it look so much brighter than the rest of the group? The reason is that it’s not a member of the Hyades cluster. It just happens to lie in the same line of sight. At 65 light-years distant, Aldebaran is 2 1/2 times closer than the rest of the cluster.

The Hyades open star cluster forms the V-shaped face of the Bull in Taurus. The bright red star Aldebaran isn’t a true cluster member. Another open star cluster, the Pleiades, is nearby. Image via EarthSky.

The busy Beehive cluster

The Beehive star cluster is another famous example of an easy-to-see open star cluster. The Beehive lies at the center of the constellation Cancer the Crab and is also known by the names M44 or Praesepe, which is Latin for manger.

At magnitude 3.7, the Beehive Cluster can be tricky to spot from a light-polluted area because of how diffuse it is; it’s spread out more than twice the size of a full moon. Using only your eyes, the open cluster will appear as a misty patch of light. Binoculars will help you focus in on a handful of stars. If you’re using a telescope, make sure to use a low-power eyepiece because the stars will spill out of your field of view.

Astronomers have found that the Beehive Cluster contains at least 1,000 stars, but only a fraction of them are visible with amateur equipment. By the way, Galileo saw 40 with his rudimentary telescope. Also, at least two planets are now known to be orbiting stars in the Beehive Cluster.

The cluster is about 730 million years old and lies approximately 577 light-years away from us. The Beehive’s age and direction of proper motion through space are similar to the Hyades cluster. This suggests that these two clusters probably had a common origin in a nebula that existed 800 million years ago.

The Beehive finder chart

Look for the Beehive open star cluster between the 2 brightest stars of the constellation Gemini the Twins, Castor and Pollux, and the star Regulus in the constellation Leo. Image via EarthSky.

View at EarthSky Community Photos. | David Hoskin in Halifax, Nova Scotia, Canada, captured the star cluster Messier 44 in the constellation Cancer on December 9, 2023. David wrote: “The Beehive is an open star cluster in the constellation Cancer. It consists of about 1,000 stars and is one of the nearest open clusters to Earth.” Thank you, David!

Bottom line: Open clusters are loosely bound gatherings of stars that may be so young that the nebulae they were born in is still visible. The Pleiades, Hyades, and the Beehive are well-known examples of open clusters.

A different kind of cluster: What’s a globular cluster?

The post Open star clusters are loose groups of stars first appeared on EarthSky.

from EarthSky https://ift.tt/2P4cERf

Pufferfish are cool but deadly: Lifeform of the week

Image via Jeffry Surianto/ Pexels.

The 2025 EarthSky Lunar Calendar presale is here! First 100 purchases signed by the legendary Deborah Byrd as a thank you. Get yours today!

Pufferfish may be used as comic relief in cartoons, swelling to three times their size when scared. But pufferfish are deadly. The poison in a single pufferfish can kill up to 30 humans. Yet in some countries, the careful preparation of this fish makes it a delicacy.

What do pufferfish look like?

Pufferfish have the shape of an ordinary fish when calm, but when they feel attacked, their extremely flexible stomachs swell with air or water. Additionally, most pufferfish have sharp spines all over their bodies, except for the eyes and mouth.

There are more than 120 species of pufferfish worldwide, and each has different morphological characteristics. But in general, you can observe patterns such as stripes and dots. As for color, pufferfish can be gray, blue, yellow, brown and white. It is curious to see the large number of interesting combinations they present.

The size of these fish varies depending on the species. The smallest in the world is the dwarf or pygmy pufferfish, which does not even reach 1.2 inches (3 cm) in length. The largest is the giant freshwater pufferfish, which is approximately 26 inches (67 cm) long.

Another distinctive feature is their four teeth, located right at the end of the mouth, two above and two below. These teeth never stop growing, so they must wear them down. To do so, they have a hard diet.

Pufferfish show stunning patterns such as stripes and dots. They can be gray, blue, yellow, brown and white. Image via Jeffry Surianto/ Pexels.

Where do they live?

You will never find them in cold waters. Pufferfish live in tropical and temperate waters around the world, and generally in shallow waters, no deeper than 980 feet (300 meters). Most species are saltwater, although there are some freshwater species.

These fish live near the coast, and their habitat consists of areas covered with algae, aquatic plants and coral reefs. In the case of freshwater species, you can find them in rivers, streams and swamps.

Pufferfish live in tropical and temperate waters around the world. Image via Jeffry Surianto/ Pexels.

How do pufferfish swell?

Pufferfish live in places frequented by larger animals. Unfortunately, pufferfish are neither agile nor fast, which is why they developed a good defense.

Pufferfish change considerably when they’re in a state of alert. At rest, they have a rounded and elongated body with a slight bulge in the lower or ventral area. When they are scared, their stomachs inflate with water if they are submerged, or with air if someone has taken them outside. They form a balloon that in most cases is protected by pointed spines. They can reach 3.3 times their resting body volume.

The pufferfish does not have scales, but it does have rough and flexible skin so that it can inflate easily. In addition, depending on the species, they are covered in different sized spikes. However, not all pufferfish have protective spines, and if they do, sometimes they are not that noticeable.

It is normal for these fish to flee when they feel threatened. They only resort to this strategy when there is no other choice, because swelling expends a lot of energy. They can remain inflated for around 15 minutes.

When they are scared, their stomachs inflate with water or air, forming a balloon protected by spines. They can reach 3.3 times their resting body volume. Image via Kevin Yi/ Pixabay.

Pufferfish are extremely poisonous

Pufferfish have two lines of defense. They can swell up to look bigger, and in many cases possess sharp spikes, but most pufferfish are also extremely poisonous. Plus, the deadly poison has an unpleasant taste. So, the pufferfish is unappetizing both to the eye and to the taste of its predators.

They are poisonous because they contain tetrodotoxin, a deadly neurotoxin that’s much stronger and faster-acting than cyanide. In fact, pufferfish are one of the most dangerous fish on the planet with this toxin that is 1,200 times more powerful than cyanide. Thus, they can kill not only animals but humans as well. One pufferfish contains enough poison to kill up to 30 adult humans.

Pufferfish are extremely poisonous. Their toxin is more powerful and faster than cyanide. Pufferfish are one of the most dangerous fish on the planet. One pufferfish contains enough poison to kill up to 30 adult humans. Image via Jack Davis/ Pexels.

Poisonous but edible?

Despite being extremely dangerous, there are humans who find its meat a delicacy. This poisonous fish is popular in Japan. But it’s only prepared by specialists. Chefs possess a special license that is difficult to obtain, after five years of experience. A slight error in its cutting and handling, and this dish could cause the death of the diners.

The poisonous parts vary depending on the type of fugu (Japanese for the pufferfish dish). For some species the skin and many parts of the meat are poisonous too!

In general, the most poisonous parts are the ovaries, liver and intestines, but an untrained chef can contaminate the entire interior during preparation. The symptoms of poisoning begin with a burning sensation in the mouth, then dizziness, numbness, body itching, rapid heart rate, low blood pressure, vomiting and, finally, muscle paralysis.

The toxin acts on the diaphragm muscle, paralyzing breathing, which leads to death. And in case you were wondering: No, there is no antidote, nor does the poison disappear after boiling or cooking the fish. You can only resort to supportive treatment when the damage has already been done. Due to its deadly nature, it is illegal to eat this fish in many countries.

Pufferfish are deadly. Even after dying and being ingested, the pufferfish is still poisonous. Only specialists can manipulate it. Image via Anastasia Pirri/ Unsplash.

What does a puffer fish feed on?

We have already talked about what happens if you try to eat pufferfish, but what does this fish feed on? Well, it feeds at night on anything it finds. However, its favorite food is small invertebrates, such as snails, clams, mussels and urchins.

The pufferfish’s four teeth are fused together and are used to break through hard surfaces. So while they can also eat algae, sponges and corals, they need hard objects to wear down their teeth. So foods like shellfish, shrimp and snails are key.

These fish feed at night and eat mostly small invertebrates, such as snails, clams, mussels and urchins. Image via Francesco Ungaro/ Pexels.

Males build sandcastles

Another interesting fact about these fish is that males are capable of building “sand castles” on the seabed to impress females. Thus, the males dig with their fins and bodies until they build beautiful geometric rings that are true works of art. To do this, the pufferfish works tirelessly for more than a week.

When the female approaches the circle, she is attracted by the spectacular drawing and decides to deposit her eggs in the center of the structure, at which time the male will be able to fertilize them.

In some pufferfish species it is the males who protect their eggs. Their job is to keep them in good condition and protected from predators until they hatch and the babies are born, after about four days. How romantic!

Conservation status of pufferfish

The International Union for Conservation of Nature Endangered lists some pufferfish species are endangered or critically endangered due to overfishing, habitat loss and pollution.

Sometimes people take these fish out of the water and leave them on the beach to die and dry, just to earn a souvenir. Remember that no matter how entertaining these animals look, they are not toys or ornaments.

What if people just want to touch them and then put them back into water? It’s dangerous to us, but also – when we touch them – we scare and stress them. When they inflate, they use up a lot of energy and become exhausted. So please, respect wildlife.

Some species are endangered or critically endangered. Image via Michael Arvedlund/ Pixabay.

Remember that no matter how entertaining these animals look, they are not toys or ornaments. Please, respect wildlife. Image via Jeffry Surianto/ Pexels.

Bottom line: Pufferfish have a cool but deadly defense. When threatened, they swell with air or water and most are covered in sharp spines. They also contain a toxin much stronger and faster-acting than cyanide.

Read more: Sea urchins are colorful and resistant: Lifeform of the week

Read more: Anglerfish are our mysterious, deep-sea lifeform of the week

The post Pufferfish are cool but deadly: Lifeform of the week first appeared on EarthSky.

from EarthSky https://ift.tt/J5cepAV

Image via Jeffry Surianto/ Pexels.

The 2025 EarthSky Lunar Calendar presale is here! First 100 purchases signed by the legendary Deborah Byrd as a thank you. Get yours today!

Pufferfish may be used as comic relief in cartoons, swelling to three times their size when scared. But pufferfish are deadly. The poison in a single pufferfish can kill up to 30 humans. Yet in some countries, the careful preparation of this fish makes it a delicacy.

What do pufferfish look like?

Pufferfish have the shape of an ordinary fish when calm, but when they feel attacked, their extremely flexible stomachs swell with air or water. Additionally, most pufferfish have sharp spines all over their bodies, except for the eyes and mouth.

There are more than 120 species of pufferfish worldwide, and each has different morphological characteristics. But in general, you can observe patterns such as stripes and dots. As for color, pufferfish can be gray, blue, yellow, brown and white. It is curious to see the large number of interesting combinations they present.

The size of these fish varies depending on the species. The smallest in the world is the dwarf or pygmy pufferfish, which does not even reach 1.2 inches (3 cm) in length. The largest is the giant freshwater pufferfish, which is approximately 26 inches (67 cm) long.

Another distinctive feature is their four teeth, located right at the end of the mouth, two above and two below. These teeth never stop growing, so they must wear them down. To do so, they have a hard diet.

Pufferfish show stunning patterns such as stripes and dots. They can be gray, blue, yellow, brown and white. Image via Jeffry Surianto/ Pexels.

Where do they live?

You will never find them in cold waters. Pufferfish live in tropical and temperate waters around the world, and generally in shallow waters, no deeper than 980 feet (300 meters). Most species are saltwater, although there are some freshwater species.

These fish live near the coast, and their habitat consists of areas covered with algae, aquatic plants and coral reefs. In the case of freshwater species, you can find them in rivers, streams and swamps.

Pufferfish live in tropical and temperate waters around the world. Image via Jeffry Surianto/ Pexels.

How do pufferfish swell?

Pufferfish live in places frequented by larger animals. Unfortunately, pufferfish are neither agile nor fast, which is why they developed a good defense.

Pufferfish change considerably when they’re in a state of alert. At rest, they have a rounded and elongated body with a slight bulge in the lower or ventral area. When they are scared, their stomachs inflate with water if they are submerged, or with air if someone has taken them outside. They form a balloon that in most cases is protected by pointed spines. They can reach 3.3 times their resting body volume.

The pufferfish does not have scales, but it does have rough and flexible skin so that it can inflate easily. In addition, depending on the species, they are covered in different sized spikes. However, not all pufferfish have protective spines, and if they do, sometimes they are not that noticeable.

It is normal for these fish to flee when they feel threatened. They only resort to this strategy when there is no other choice, because swelling expends a lot of energy. They can remain inflated for around 15 minutes.

When they are scared, their stomachs inflate with water or air, forming a balloon protected by spines. They can reach 3.3 times their resting body volume. Image via Kevin Yi/ Pixabay.

Pufferfish are extremely poisonous

Pufferfish have two lines of defense. They can swell up to look bigger, and in many cases possess sharp spikes, but most pufferfish are also extremely poisonous. Plus, the deadly poison has an unpleasant taste. So, the pufferfish is unappetizing both to the eye and to the taste of its predators.

They are poisonous because they contain tetrodotoxin, a deadly neurotoxin that’s much stronger and faster-acting than cyanide. In fact, pufferfish are one of the most dangerous fish on the planet with this toxin that is 1,200 times more powerful than cyanide. Thus, they can kill not only animals but humans as well. One pufferfish contains enough poison to kill up to 30 adult humans.

Pufferfish are extremely poisonous. Their toxin is more powerful and faster than cyanide. Pufferfish are one of the most dangerous fish on the planet. One pufferfish contains enough poison to kill up to 30 adult humans. Image via Jack Davis/ Pexels.

Poisonous but edible?

Despite being extremely dangerous, there are humans who find its meat a delicacy. This poisonous fish is popular in Japan. But it’s only prepared by specialists. Chefs possess a special license that is difficult to obtain, after five years of experience. A slight error in its cutting and handling, and this dish could cause the death of the diners.

The poisonous parts vary depending on the type of fugu (Japanese for the pufferfish dish). For some species the skin and many parts of the meat are poisonous too!

In general, the most poisonous parts are the ovaries, liver and intestines, but an untrained chef can contaminate the entire interior during preparation. The symptoms of poisoning begin with a burning sensation in the mouth, then dizziness, numbness, body itching, rapid heart rate, low blood pressure, vomiting and, finally, muscle paralysis.

The toxin acts on the diaphragm muscle, paralyzing breathing, which leads to death. And in case you were wondering: No, there is no antidote, nor does the poison disappear after boiling or cooking the fish. You can only resort to supportive treatment when the damage has already been done. Due to its deadly nature, it is illegal to eat this fish in many countries.

Pufferfish are deadly. Even after dying and being ingested, the pufferfish is still poisonous. Only specialists can manipulate it. Image via Anastasia Pirri/ Unsplash.

What does a puffer fish feed on?

We have already talked about what happens if you try to eat pufferfish, but what does this fish feed on? Well, it feeds at night on anything it finds. However, its favorite food is small invertebrates, such as snails, clams, mussels and urchins.

The pufferfish’s four teeth are fused together and are used to break through hard surfaces. So while they can also eat algae, sponges and corals, they need hard objects to wear down their teeth. So foods like shellfish, shrimp and snails are key.

These fish feed at night and eat mostly small invertebrates, such as snails, clams, mussels and urchins. Image via Francesco Ungaro/ Pexels.

Males build sandcastles

Another interesting fact about these fish is that males are capable of building “sand castles” on the seabed to impress females. Thus, the males dig with their fins and bodies until they build beautiful geometric rings that are true works of art. To do this, the pufferfish works tirelessly for more than a week.

When the female approaches the circle, she is attracted by the spectacular drawing and decides to deposit her eggs in the center of the structure, at which time the male will be able to fertilize them.

In some pufferfish species it is the males who protect their eggs. Their job is to keep them in good condition and protected from predators until they hatch and the babies are born, after about four days. How romantic!

Conservation status of pufferfish

The International Union for Conservation of Nature Endangered lists some pufferfish species are endangered or critically endangered due to overfishing, habitat loss and pollution.

Sometimes people take these fish out of the water and leave them on the beach to die and dry, just to earn a souvenir. Remember that no matter how entertaining these animals look, they are not toys or ornaments.

What if people just want to touch them and then put them back into water? It’s dangerous to us, but also – when we touch them – we scare and stress them. When they inflate, they use up a lot of energy and become exhausted. So please, respect wildlife.

Some species are endangered or critically endangered. Image via Michael Arvedlund/ Pixabay.

Remember that no matter how entertaining these animals look, they are not toys or ornaments. Please, respect wildlife. Image via Jeffry Surianto/ Pexels.

Bottom line: Pufferfish have a cool but deadly defense. When threatened, they swell with air or water and most are covered in sharp spines. They also contain a toxin much stronger and faster-acting than cyanide.

Read more: Sea urchins are colorful and resistant: Lifeform of the week

Read more: Anglerfish are our mysterious, deep-sea lifeform of the week

The post Pufferfish are cool but deadly: Lifeform of the week first appeared on EarthSky.

from EarthSky https://ift.tt/J5cepAV

Giant rats could help detect illegal wildlife trade

A new study shows that African giant pouched rats can detect illegally trafficked wildlife, even when it has been concealed among other substances. Giant rats could be a new line of defense against the illegal wildlife trade. Image via APOPO/ Frontiers. Used with permission.

The 2025 EarthSky Lunar Calendar presale is here! First 100 purchases signed by the legendary Deborah Byrd as a thank you. Get yours today!

• African giant pouched rats have a keen sense of smell. They’ve been used in the past to sniff out explosives and more.
• Now giant rats are learning to sniff out illegally trafficked wildlife, such as pangolin scales, elephant tusks, rhino horn and rare wood.
• Smugglers who deal in illegal wildlife are also often involved in other illegal activities, including human, drug and arms trafficking. So the rats could assist with the global fight against networks that exploit humans and nature.

Frontiers published this original article on October 29, 2024. Edits by EarthSky.

Giant rats could help detect illegal wildlife trade

Pangolin scales, elephant tusks, rhino horn and a rare wood are preferred objects in the illegal wildlife trade. African giant pouched rats, with their keen sense of smell, however, could soon help to intercept this trade. Researchers showed the rats can successfully sniff out parts of endangered animals and remember the scent months after training. Employing them in the field could increase pressure on wildlife smugglers and add a flexibly deployable tool to screen cargo, the researchers said.

In the past, African giant pouched rats have learned to detect explosives and the tuberculosis-causing pathogen. Now, a team of researchers have trained these rats to pick up the scent of pangolin scales, elephant ivory, rhino horn and African blackwood. These animals and plants are threatened and at high danger of extinction.

Isabelle Szott, a researcher at the Okeanos Foundation, is the first co-author of the study published in Frontiers in Conservation Science. Szott said:

Our study shows that we can train African giant pouched rats to detect illegally trafficked wildlife, even when it has been concealed among other substances.

First co-author Kate Webb, an assistant professor at Duke University, added:

The rats also continued to detect the wildlife targets after not encountering that species for a long period.

The researchers conducted their study at APOPO, a Tanzania-based, non-profit organization that provides a low-tech, cost-efficient solutions to pressing humanitarian challenges.

Ratting out wildlife trafficking

The rats – Kirsty, Marty, Attenborough, Irwin, Betty, Teddy, Ivory, Ebony, Desmond, Thoreau and Fossey, some of them named after conservationists and advocates against wildlife trafficking – underwent several training stages. During indication training, the rats learned to hold their noses for several seconds in a hole where the target was. When they correctly performed this ‘nose poke,’ they received a reward with flavored rodent pellets.

In the next step, researchers introduced the rats to non-target odors. These included electric cables, coffee beans and washing powder. Smugglers frequently use these objects to mask the scent of wildlife in real-life trafficking operations. Szott said:

During the discrimination stage, rats learn to only signal the odors of the wildlife targets, while ignoring non-targets.

Researchers also trained the rats to remember smells. At the end of their retention training, they were reintroduced to scents they’d not encountered for five and eight months, respectively. Despite months of non-exposure, the rats showed perfect retention scores, suggesting that their cognitive retention performance resembles that of dogs.

By the end of the training, eight rats were able to identify four commonly smuggled wildlife species among 146 non-target substances.

Good giant rats!

During indication training, rats received rewards when they correctly performed a ‘nose poke’ in a hole containing a target. Image via APOPO/ Frontiers. Used with permission.

During their training, the rats received rewards with flavored rodent pellets. Image via APOPO/ Frontiers. Used with permission.

The researchers used a custom-built semi-automated line cage to train the rats. It has 10 holes along the floor, spaced 4 inches (10 cm) apart. Scent samples, in aluminum cassettes, were underneath the floor. Metal sliding plates in the floor can open and close for access to scent samples. Pictured here is the similar fully automated cage. Image via APOPO/ Frontiers. Used with permission.

Rats in action

Szott explained:

Existing screening tools are expensive and time intensive, and there is an urgent need to increase cargo screening. APOPO’s rats are cost-efficient scent detection tools. They can easily access tight spaces like cargo in packed shipping containers or be lifted up high to screen the ventilation systems of sealed containers.

The next step, the scientists said, is to develop ways for the rats to work within ports through which smugglers trafficked wildlife. For this purpose, researchers will outfit the rats with custom-made vests. With their front paws, they will be able to pull a small ball attached at the chest of their vest, which emits a beeping sound. This way rats will be able to alert their handlers when they detect a target. Webb said:

The vests are a great example of developing hardware that could be useful across different settings and tasks, including at a shipping port to detect smuggled wildlife.

This proof-of-principle study demonstrates that rats can successfully identify trafficked wildlife. This does not mean that it comes without limitations, the researchers said. For example, they conducted the study in a controlled environment, which is not reflective of the settings in which wildlife is commonly trafficked or screened by scent-detection animals. To deploy rats for this task, the researchers said they would need to develop new methods.

Webb concluded:

Wildlife smuggling is often conducted by individuals engaged in other illegal activities, including human, drug and arms trafficking. Therefore, deploying rats to combat wildlife trafficking may assist with the global fight against networks that exploit humans and nature.

Giant rats learning their roles

In real-life settings, rats will be able to pull a small ball attached at the chest of their vest, which emits a beeping sound. This way rats will be able to alert their handlers when they detect a target. Image via APOPO/ Frontiers. Used with permission.

The rats learned to identify and remember the scent of 4 wildlife samples. These are samples of pangolin scales. All pangolin species are on the threatened tier of the IUCN Red List. Image via APOPO/ Frontiers. Used with permission.

Giant African pouched rat with trainer. Image via APOPO/ Frontiers. Used with permission.

Bottom line: Researchers are training giant rats to sniff out illegal wildlife samples in an effort to curb the trade of these materials.

Via Frontiers

Read more: Kangaroo rats are desert dwellers: Lifeform of the week

Read more: How naked mole rats stay cancer-free

The post Giant rats could help detect illegal wildlife trade first appeared on EarthSky.

from EarthSky https://ift.tt/YIxPn8i

A new study shows that African giant pouched rats can detect illegally trafficked wildlife, even when it has been concealed among other substances. Giant rats could be a new line of defense against the illegal wildlife trade. Image via APOPO/ Frontiers. Used with permission.

The 2025 EarthSky Lunar Calendar presale is here! First 100 purchases signed by the legendary Deborah Byrd as a thank you. Get yours today!

• African giant pouched rats have a keen sense of smell. They’ve been used in the past to sniff out explosives and more.
• Now giant rats are learning to sniff out illegally trafficked wildlife, such as pangolin scales, elephant tusks, rhino horn and rare wood.
• Smugglers who deal in illegal wildlife are also often involved in other illegal activities, including human, drug and arms trafficking. So the rats could assist with the global fight against networks that exploit humans and nature.

Frontiers published this original article on October 29, 2024. Edits by EarthSky.

Giant rats could help detect illegal wildlife trade

Pangolin scales, elephant tusks, rhino horn and a rare wood are preferred objects in the illegal wildlife trade. African giant pouched rats, with their keen sense of smell, however, could soon help to intercept this trade. Researchers showed the rats can successfully sniff out parts of endangered animals and remember the scent months after training. Employing them in the field could increase pressure on wildlife smugglers and add a flexibly deployable tool to screen cargo, the researchers said.

In the past, African giant pouched rats have learned to detect explosives and the tuberculosis-causing pathogen. Now, a team of researchers have trained these rats to pick up the scent of pangolin scales, elephant ivory, rhino horn and African blackwood. These animals and plants are threatened and at high danger of extinction.

Isabelle Szott, a researcher at the Okeanos Foundation, is the first co-author of the study published in Frontiers in Conservation Science. Szott said:

Our study shows that we can train African giant pouched rats to detect illegally trafficked wildlife, even when it has been concealed among other substances.

First co-author Kate Webb, an assistant professor at Duke University, added:

The rats also continued to detect the wildlife targets after not encountering that species for a long period.

The researchers conducted their study at APOPO, a Tanzania-based, non-profit organization that provides a low-tech, cost-efficient solutions to pressing humanitarian challenges.

Ratting out wildlife trafficking

The rats – Kirsty, Marty, Attenborough, Irwin, Betty, Teddy, Ivory, Ebony, Desmond, Thoreau and Fossey, some of them named after conservationists and advocates against wildlife trafficking – underwent several training stages. During indication training, the rats learned to hold their noses for several seconds in a hole where the target was. When they correctly performed this ‘nose poke,’ they received a reward with flavored rodent pellets.

In the next step, researchers introduced the rats to non-target odors. These included electric cables, coffee beans and washing powder. Smugglers frequently use these objects to mask the scent of wildlife in real-life trafficking operations. Szott said:

During the discrimination stage, rats learn to only signal the odors of the wildlife targets, while ignoring non-targets.

Researchers also trained the rats to remember smells. At the end of their retention training, they were reintroduced to scents they’d not encountered for five and eight months, respectively. Despite months of non-exposure, the rats showed perfect retention scores, suggesting that their cognitive retention performance resembles that of dogs.

By the end of the training, eight rats were able to identify four commonly smuggled wildlife species among 146 non-target substances.

Good giant rats!

During indication training, rats received rewards when they correctly performed a ‘nose poke’ in a hole containing a target. Image via APOPO/ Frontiers. Used with permission.

During their training, the rats received rewards with flavored rodent pellets. Image via APOPO/ Frontiers. Used with permission.

The researchers used a custom-built semi-automated line cage to train the rats. It has 10 holes along the floor, spaced 4 inches (10 cm) apart. Scent samples, in aluminum cassettes, were underneath the floor. Metal sliding plates in the floor can open and close for access to scent samples. Pictured here is the similar fully automated cage. Image via APOPO/ Frontiers. Used with permission.

Rats in action

Szott explained:

Existing screening tools are expensive and time intensive, and there is an urgent need to increase cargo screening. APOPO’s rats are cost-efficient scent detection tools. They can easily access tight spaces like cargo in packed shipping containers or be lifted up high to screen the ventilation systems of sealed containers.

The next step, the scientists said, is to develop ways for the rats to work within ports through which smugglers trafficked wildlife. For this purpose, researchers will outfit the rats with custom-made vests. With their front paws, they will be able to pull a small ball attached at the chest of their vest, which emits a beeping sound. This way rats will be able to alert their handlers when they detect a target. Webb said:

The vests are a great example of developing hardware that could be useful across different settings and tasks, including at a shipping port to detect smuggled wildlife.

This proof-of-principle study demonstrates that rats can successfully identify trafficked wildlife. This does not mean that it comes without limitations, the researchers said. For example, they conducted the study in a controlled environment, which is not reflective of the settings in which wildlife is commonly trafficked or screened by scent-detection animals. To deploy rats for this task, the researchers said they would need to develop new methods.

Webb concluded:

Wildlife smuggling is often conducted by individuals engaged in other illegal activities, including human, drug and arms trafficking. Therefore, deploying rats to combat wildlife trafficking may assist with the global fight against networks that exploit humans and nature.

Giant rats learning their roles

In real-life settings, rats will be able to pull a small ball attached at the chest of their vest, which emits a beeping sound. This way rats will be able to alert their handlers when they detect a target. Image via APOPO/ Frontiers. Used with permission.

The rats learned to identify and remember the scent of 4 wildlife samples. These are samples of pangolin scales. All pangolin species are on the threatened tier of the IUCN Red List. Image via APOPO/ Frontiers. Used with permission.

Giant African pouched rat with trainer. Image via APOPO/ Frontiers. Used with permission.

Bottom line: Researchers are training giant rats to sniff out illegal wildlife samples in an effort to curb the trade of these materials.

Via Frontiers

Read more: Kangaroo rats are desert dwellers: Lifeform of the week

Read more: How naked mole rats stay cancer-free

The post Giant rats could help detect illegal wildlife trade first appeared on EarthSky.

from EarthSky https://ift.tt/YIxPn8i