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La Niña is here! Here’s what that means for our weather

La Niña: Map of North America with a thick blue line dipping through the states and other colors in different regions.
La Niña is here! Read on to find out more about this weather pattern and what it means for our winter weather. Image via NOAA.

La Niña is here!

Meteorologists have been expecting it for months, and now La Niña conditions have finally emerged in the tropical Pacific Ocean. A La Niña Advisory is currently in place with a 59% chance of continuing through April 2025. According to the Climate Prediction Center, the La Niña will be weak and eventually transition into a neutral phase.

What is La Niña and El Niño?

La Niña is one phase of the climate pattern called the El Niño Southern Oscillation (ENSO), which forms in the tropical Pacific. La Niña is the “cool” phase of ENSO, since the waters in this part of the Pacific are cooler than average. El Niño is the “warm” phase of ENSO, as the waters in the tropical Pacific are warmer than average. While the focus is typically on El Niño and La Niña, there is also a neutral phase. The neutral phase of ENSO basically means everything in this part of the Pacific Ocean is at or near their averages.

During La Niña, the phase we’re in now, the trade winds over the tropical Pacific Ocean are stronger than average, which creates upwelling. Upwelling brings up cooler water from deep in the ocean, causing water temperatures to drop. Also over this part of the ocean, the air sinks, leading to less rainfall. There is rising air and therefore more rain over places like Indonesia, however.

Flat map of the world with arrows showing where air rises and sinks along with ocean currents.
During La Niña, air sinks over areas such as the eastern Pacific Ocean and rises over the western Pacific Ocean, such as in Indonesia. Image via NOAA.

It’s the opposite during El Niño: The winds over the tropical Pacific Ocean are weaker, and so waters stay warmer. This leads to rising motion and more active, rainy weather over this part of the ocean, while sinking air leads to calm, drier weather in other places, such as Indonesia.

Flat map of world with arrows going up and down and across the oceans.
El Nino leads to wetter conditions in places like the southern United States. Image via NOAA.

Walker Circulation

ENSO plays an important role in the Walker Circulation. The Walker Circulation is a cycle of rising and sinking air between the typically warmer waters of the western Pacific Ocean and the cooler waters of the eastern Pacific Ocean. It’s this Walker Circulation that helps drive the rising motion and, therefore, rain and storm activity.

What does this mean for the rest of winter?

This large circulation pattern has more of an impact on the United States in the winter, as the overall circulation can influence the location of the jet stream, a major driver for weather. So a La Niña winter for the United States (and parts of their neighbors to the north in Canada) typically features cooler weather from Alaska down to the northern Plains. It also means drier, warmer conditions from the desert southwest to the southeast. (See the map at the top of this post.)

In other parts of the world, especially for those near the western Pacific Ocean (in the Northern Hemisphere), meteorologists expect a more active, rainy trend through March.

Will La Niña impact summer and the Atlantic hurricane season?

La Niña in its current phase is not expected to last into the summer. The Climate Prediction Center anticipates the ENSO phase to become neutral sometime between March and May.

If La Niña were to remain in place for the upcoming Atlantic hurricane season, it would have had an influence on how active it could be. La Niña supports rising motion in the tropical Atlantic. And that would allow any forming tropical system to develop quickly. (Also, wind shear – the strong upper-level winds – are lower in the tropical Atlantic during La Niña. Wind shear can weaken or tear apart tropical systems, so lower wind shear would also allow for more easy tropical development.)

Map of the Western Hemisphere showing colorful patches and text explanations.
If La Niña were to remain in place for the upcoming Atlantic hurricane season, here’s what to expect. Image via NOAA.

The forecast and outcome

The Climate Prediction Center issued a La Niña Watch during the summer of 2024 in anticipation of the development of this ENSO phase. A La Niña Watch gets issued when a La Niña is expected to develop within the next six months. At the time, meteorologists expected La Niña would develop during the summer, impacting the already active Atlantic hurricane season. But La Niña ended up not developing until December. The National Oceanic and Atmospheric Administration speculates that because the oceans have been running well above average for more than a year, it delayed the onset of the cool phase, La Niña.

Bottom line: After being expected for months, La Niña conditions have finally emerged in the tropical Pacific Ocean. Here’s what that means for our weather.

Via NOAA and National Weather Service

The post La Niña is here! Here’s what that means for our weather first appeared on EarthSky.



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La Niña: Map of North America with a thick blue line dipping through the states and other colors in different regions.
La Niña is here! Read on to find out more about this weather pattern and what it means for our winter weather. Image via NOAA.

La Niña is here!

Meteorologists have been expecting it for months, and now La Niña conditions have finally emerged in the tropical Pacific Ocean. A La Niña Advisory is currently in place with a 59% chance of continuing through April 2025. According to the Climate Prediction Center, the La Niña will be weak and eventually transition into a neutral phase.

What is La Niña and El Niño?

La Niña is one phase of the climate pattern called the El Niño Southern Oscillation (ENSO), which forms in the tropical Pacific. La Niña is the “cool” phase of ENSO, since the waters in this part of the Pacific are cooler than average. El Niño is the “warm” phase of ENSO, as the waters in the tropical Pacific are warmer than average. While the focus is typically on El Niño and La Niña, there is also a neutral phase. The neutral phase of ENSO basically means everything in this part of the Pacific Ocean is at or near their averages.

During La Niña, the phase we’re in now, the trade winds over the tropical Pacific Ocean are stronger than average, which creates upwelling. Upwelling brings up cooler water from deep in the ocean, causing water temperatures to drop. Also over this part of the ocean, the air sinks, leading to less rainfall. There is rising air and therefore more rain over places like Indonesia, however.

Flat map of the world with arrows showing where air rises and sinks along with ocean currents.
During La Niña, air sinks over areas such as the eastern Pacific Ocean and rises over the western Pacific Ocean, such as in Indonesia. Image via NOAA.

It’s the opposite during El Niño: The winds over the tropical Pacific Ocean are weaker, and so waters stay warmer. This leads to rising motion and more active, rainy weather over this part of the ocean, while sinking air leads to calm, drier weather in other places, such as Indonesia.

Flat map of world with arrows going up and down and across the oceans.
El Nino leads to wetter conditions in places like the southern United States. Image via NOAA.

Walker Circulation

ENSO plays an important role in the Walker Circulation. The Walker Circulation is a cycle of rising and sinking air between the typically warmer waters of the western Pacific Ocean and the cooler waters of the eastern Pacific Ocean. It’s this Walker Circulation that helps drive the rising motion and, therefore, rain and storm activity.

What does this mean for the rest of winter?

This large circulation pattern has more of an impact on the United States in the winter, as the overall circulation can influence the location of the jet stream, a major driver for weather. So a La Niña winter for the United States (and parts of their neighbors to the north in Canada) typically features cooler weather from Alaska down to the northern Plains. It also means drier, warmer conditions from the desert southwest to the southeast. (See the map at the top of this post.)

In other parts of the world, especially for those near the western Pacific Ocean (in the Northern Hemisphere), meteorologists expect a more active, rainy trend through March.

Will La Niña impact summer and the Atlantic hurricane season?

La Niña in its current phase is not expected to last into the summer. The Climate Prediction Center anticipates the ENSO phase to become neutral sometime between March and May.

If La Niña were to remain in place for the upcoming Atlantic hurricane season, it would have had an influence on how active it could be. La Niña supports rising motion in the tropical Atlantic. And that would allow any forming tropical system to develop quickly. (Also, wind shear – the strong upper-level winds – are lower in the tropical Atlantic during La Niña. Wind shear can weaken or tear apart tropical systems, so lower wind shear would also allow for more easy tropical development.)

Map of the Western Hemisphere showing colorful patches and text explanations.
If La Niña were to remain in place for the upcoming Atlantic hurricane season, here’s what to expect. Image via NOAA.

The forecast and outcome

The Climate Prediction Center issued a La Niña Watch during the summer of 2024 in anticipation of the development of this ENSO phase. A La Niña Watch gets issued when a La Niña is expected to develop within the next six months. At the time, meteorologists expected La Niña would develop during the summer, impacting the already active Atlantic hurricane season. But La Niña ended up not developing until December. The National Oceanic and Atmospheric Administration speculates that because the oceans have been running well above average for more than a year, it delayed the onset of the cool phase, La Niña.

Bottom line: After being expected for months, La Niña conditions have finally emerged in the tropical Pacific Ocean. Here’s what that means for our weather.

Via NOAA and National Weather Service

The post La Niña is here! Here’s what that means for our weather first appeared on EarthSky.



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Beloved Gaia spacecraft ending its observations

Gaia: Glowing band of stars in space and spacecraft with square body set in the center of a dish-shaped antenna.
Artist’s concept of ESA’s Gaia spacecraft mapping the stars of the Milky Way. Gaia’s observations will come to an end on January 15, 2025. Image via ESA/ ATG medialab. Background ESO/ S. Brunier.

The 2025 EarthSky lunar calendar available now. Moon phases every day on a poster-sized calendar. Get yours today!

Beloved spacecraft ending its operations

Today, Wednesday, January 15, 2025, the Gaia spacecraft will take its final measurements of our Milky Way galaxy. Gaia – a mission of the European Space Agency – launched in 2013 and has been expanding our view of our home galaxy since its arrival at Lagrange Point 2 in 2014. Lagrangian points are locations in space where gravitational forces and the orbital motion of a body balance each other. The goal of Gaia was to make a precise 3D map of the Milky Way. Over the past decade, it has tracked and measured the motions, luminosity, temperature and composition of nearly 2 billion objects.

But ESA said that the cold gas propellant that keeps the mission working is running out. While Gaia will cease taking measurements of our galaxy, the data releases from the project will continue for some years yet. Gaia’s first three data releases came in 2016, 2018 and 2022. The 4th data release should be ready in 2026. And the 5th and final data release covering all 10 1/2 years of data will be around the end of the decade. The massive amounts of data take quite a long time to process!

What will happen to Gaia next?

Gaia will not float out at the Lagrange Point 2 forever. Engineers have planned to remove Gaia from its current orbit. ESA said:

Gaia will be inserted into an orbit that makes sure it does not come too close to the Earth-moon system in the near future. The Gaia spacecraft will be fully passivated when it moves to its final orbit, to avoid any harm or interference with other spacecraft.

After January 15, Gaia will undergo some testing, which will make it temporarily brighter in the sky. Normally, Gaia has been a very faint magnitude 21 as it orbits the sun out at Lagrange Point 2. But for while it will brighten to magnitude 15. That’s still incredibly faint for the casual observer. You’d need quite a large telescope to track it down. But if that’s your kind of fun, here’s information on how to find it.

What has Gaia already shown us?

Astronomers have used the data from Gaia to make all sorts of new discoveries about our galaxy. Here are some highlights:

Also, Gaia has made discoveries outside of the Milky Way, including spotting stars flying between galaxies and the discovery of an enormous ghost galaxy on the Milky Way’s outskirts.

Watch what Phil Plait had to say about Gaia during a recent livestream with Deborah Byrd.

Bottom line: ESA’s Gaia spacecraft has spent more than a decade measuring nearly 2 billion objects in our Milky Way galaxy. Its measurements end on January 15, 2025.

Via ESA

The post Beloved Gaia spacecraft ending its observations first appeared on EarthSky.



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Gaia: Glowing band of stars in space and spacecraft with square body set in the center of a dish-shaped antenna.
Artist’s concept of ESA’s Gaia spacecraft mapping the stars of the Milky Way. Gaia’s observations will come to an end on January 15, 2025. Image via ESA/ ATG medialab. Background ESO/ S. Brunier.

The 2025 EarthSky lunar calendar available now. Moon phases every day on a poster-sized calendar. Get yours today!

Beloved spacecraft ending its operations

Today, Wednesday, January 15, 2025, the Gaia spacecraft will take its final measurements of our Milky Way galaxy. Gaia – a mission of the European Space Agency – launched in 2013 and has been expanding our view of our home galaxy since its arrival at Lagrange Point 2 in 2014. Lagrangian points are locations in space where gravitational forces and the orbital motion of a body balance each other. The goal of Gaia was to make a precise 3D map of the Milky Way. Over the past decade, it has tracked and measured the motions, luminosity, temperature and composition of nearly 2 billion objects.

But ESA said that the cold gas propellant that keeps the mission working is running out. While Gaia will cease taking measurements of our galaxy, the data releases from the project will continue for some years yet. Gaia’s first three data releases came in 2016, 2018 and 2022. The 4th data release should be ready in 2026. And the 5th and final data release covering all 10 1/2 years of data will be around the end of the decade. The massive amounts of data take quite a long time to process!

What will happen to Gaia next?

Gaia will not float out at the Lagrange Point 2 forever. Engineers have planned to remove Gaia from its current orbit. ESA said:

Gaia will be inserted into an orbit that makes sure it does not come too close to the Earth-moon system in the near future. The Gaia spacecraft will be fully passivated when it moves to its final orbit, to avoid any harm or interference with other spacecraft.

After January 15, Gaia will undergo some testing, which will make it temporarily brighter in the sky. Normally, Gaia has been a very faint magnitude 21 as it orbits the sun out at Lagrange Point 2. But for while it will brighten to magnitude 15. That’s still incredibly faint for the casual observer. You’d need quite a large telescope to track it down. But if that’s your kind of fun, here’s information on how to find it.

What has Gaia already shown us?

Astronomers have used the data from Gaia to make all sorts of new discoveries about our galaxy. Here are some highlights:

Also, Gaia has made discoveries outside of the Milky Way, including spotting stars flying between galaxies and the discovery of an enormous ghost galaxy on the Milky Way’s outskirts.

Watch what Phil Plait had to say about Gaia during a recent livestream with Deborah Byrd.

Bottom line: ESA’s Gaia spacecraft has spent more than a decade measuring nearly 2 billion objects in our Milky Way galaxy. Its measurements end on January 15, 2025.

Via ESA

The post Beloved Gaia spacecraft ending its observations first appeared on EarthSky.



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Huygens landed on Saturn’s moon Titan 20 years ago


Watch as Huygens descends through the atmosphere of Saturn’s moon Titan and lands on its surface on January 14, 2005.

Huygens landed on Saturn’s moon Titan 20 years ago

Right now, space probes are speeding toward the moons in the outer solar system, ready to explore these icy ocean worlds. JUICE is headed toward Jupiter’s icy moons, while Europa Clipper is zeroing in on one of Jupiter’s moons, Europa, where there’s already scientific evidence for the ingredients of life. But did you know we’ve already landed on a moon of a gas giant? On January 14, 2005, ESA’s Huygens spacecraft descended through the atmosphere of Saturn’s moon Titan, to what astronomers thought might be a wet world, but in reality it looked a bit like … Mars?

Huygens made the trip to Saturn aboard NASA’s Cassini spacecraft. After Huygens patiently waited its turn aboard Cassini for seven years, Cassini released Huygens on its trip toward Titan on December 25, 2004. On January 14, Huygens entered the moon’s atmosphere and took two hours to reach the surface. And on the surface it continued to record and send information for about 90 minutes.

The 2025 EarthSky Lunar Calendar is now available! A unique and beautiful poster-sized calendar. Get yours today!

The descent and landing

Here’s NASA’s description of the event:

Huygens entered Titan’s atmosphere at 09:05:56 UTC on January 14, 2005, and within four minutes had deployed its 28-foot (8.5-meter) diameter main parachute.

A minute later, Huygens began transmitting a wealth of information back to Cassini for more than two hours before impacting on the surface of Titan at 11:38:11 UTC at a velocity of 15 feet per second (4.54 meters per second). Landing coordinates were 192.32 degrees west longitude and 10.25 degrees south latitude, about 4 miles (7 kilometers) from its target point.

A problem in the communications program limited the number of images that Huygens transmitted to Cassini, from about 700 to 376. Yet, to the excitement of planetary scientists back on Earth, it continued its transmissions for another three hours and 10 minutes. During this time it transmitted a view of its surroundings (224 images of the same view).

Huygens appears to have landed on a surface resembling sand made of ice grains. Surface pictures showed a flat plain littered with pebbles as well as evidence of liquid acting on the terrain in the recent past. Subsequent data confirmed the existence of liquid hydrocarbon lakes in the polar regions of Titan.

Huygens images of Titan’s surface

Check out these views from Huygens as the spacecraft descended through Titan’s hazy atmosphere and then made out the varied terrain below.

Huygens: 6 panels showing a rugged landscape in increasing detail from blurry to crisp.
Here are 6 fisheye views that Huygens captured on its descent through Titan’s atmosphere and to the surface. Image via ESA/ NASA/ JPL/ University of Arizona.
4 panels showing mountainous landforms seen from above and then increasingly from the side as the lander descends.
Here’s another collection of 4 images from Huygens on January 14, 2005. The spacecraft broke out of the haze in Titan’s atmosphere and got a view of the rugged terrain below. Image via ESA/ NASA/ JPL/ University of Arizona.

And here was the view from Titan’s surface.

Yellowish ground with many rounded rocks of the same color under a yellow sky.
Huygens captured this view of Titan’s surface on January 14, 2005. It shows pebble-sized rocks or ice blocks. Image via ESA/ NASA/ JPL/ University of Arizona.

Next up, Europa Clipper and JUICE

How different – or similar – will our views of Jupiter’s moons be? Europa Clipper will arrive at Europa in 2030 and JUICE will reach the Jovian moons in 2031. The Europa Clipper mission will only perform flybys of Europa, no landing. But, interestingly, both Europa Clipper and JUICE will end their missions by deliberately crashing into Ganymede. ESA said:

… there is the possibility that – depending on the missions’ end dates – one spacecraft might have the chance to observe the effects of the other’s impact.

Bottom line: On January 14, 2005, the Huygens spacecraft descended through the atmosphere of Saturn’s moon Titan and landed on its surface. See the 20th anniversary images of Titan here.

The post Huygens landed on Saturn’s moon Titan 20 years ago first appeared on EarthSky.



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Watch as Huygens descends through the atmosphere of Saturn’s moon Titan and lands on its surface on January 14, 2005.

Huygens landed on Saturn’s moon Titan 20 years ago

Right now, space probes are speeding toward the moons in the outer solar system, ready to explore these icy ocean worlds. JUICE is headed toward Jupiter’s icy moons, while Europa Clipper is zeroing in on one of Jupiter’s moons, Europa, where there’s already scientific evidence for the ingredients of life. But did you know we’ve already landed on a moon of a gas giant? On January 14, 2005, ESA’s Huygens spacecraft descended through the atmosphere of Saturn’s moon Titan, to what astronomers thought might be a wet world, but in reality it looked a bit like … Mars?

Huygens made the trip to Saturn aboard NASA’s Cassini spacecraft. After Huygens patiently waited its turn aboard Cassini for seven years, Cassini released Huygens on its trip toward Titan on December 25, 2004. On January 14, Huygens entered the moon’s atmosphere and took two hours to reach the surface. And on the surface it continued to record and send information for about 90 minutes.

The 2025 EarthSky Lunar Calendar is now available! A unique and beautiful poster-sized calendar. Get yours today!

The descent and landing

Here’s NASA’s description of the event:

Huygens entered Titan’s atmosphere at 09:05:56 UTC on January 14, 2005, and within four minutes had deployed its 28-foot (8.5-meter) diameter main parachute.

A minute later, Huygens began transmitting a wealth of information back to Cassini for more than two hours before impacting on the surface of Titan at 11:38:11 UTC at a velocity of 15 feet per second (4.54 meters per second). Landing coordinates were 192.32 degrees west longitude and 10.25 degrees south latitude, about 4 miles (7 kilometers) from its target point.

A problem in the communications program limited the number of images that Huygens transmitted to Cassini, from about 700 to 376. Yet, to the excitement of planetary scientists back on Earth, it continued its transmissions for another three hours and 10 minutes. During this time it transmitted a view of its surroundings (224 images of the same view).

Huygens appears to have landed on a surface resembling sand made of ice grains. Surface pictures showed a flat plain littered with pebbles as well as evidence of liquid acting on the terrain in the recent past. Subsequent data confirmed the existence of liquid hydrocarbon lakes in the polar regions of Titan.

Huygens images of Titan’s surface

Check out these views from Huygens as the spacecraft descended through Titan’s hazy atmosphere and then made out the varied terrain below.

Huygens: 6 panels showing a rugged landscape in increasing detail from blurry to crisp.
Here are 6 fisheye views that Huygens captured on its descent through Titan’s atmosphere and to the surface. Image via ESA/ NASA/ JPL/ University of Arizona.
4 panels showing mountainous landforms seen from above and then increasingly from the side as the lander descends.
Here’s another collection of 4 images from Huygens on January 14, 2005. The spacecraft broke out of the haze in Titan’s atmosphere and got a view of the rugged terrain below. Image via ESA/ NASA/ JPL/ University of Arizona.

And here was the view from Titan’s surface.

Yellowish ground with many rounded rocks of the same color under a yellow sky.
Huygens captured this view of Titan’s surface on January 14, 2005. It shows pebble-sized rocks or ice blocks. Image via ESA/ NASA/ JPL/ University of Arizona.

Next up, Europa Clipper and JUICE

How different – or similar – will our views of Jupiter’s moons be? Europa Clipper will arrive at Europa in 2030 and JUICE will reach the Jovian moons in 2031. The Europa Clipper mission will only perform flybys of Europa, no landing. But, interestingly, both Europa Clipper and JUICE will end their missions by deliberately crashing into Ganymede. ESA said:

… there is the possibility that – depending on the missions’ end dates – one spacecraft might have the chance to observe the effects of the other’s impact.

Bottom line: On January 14, 2005, the Huygens spacecraft descended through the atmosphere of Saturn’s moon Titan and landed on its surface. See the 20th anniversary images of Titan here.

The post Huygens landed on Saturn’s moon Titan 20 years ago first appeared on EarthSky.



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Surprising spiral galaxy hosting quasar jet

Spiral galaxy hosting quasar: Quasar-jet-in-spiral-galaxy-Jan-13-2025-Hubble
This image from the Hubble Space Telescope indicates a spiral galaxy hosting quasar. Hubble captured hints of interaction, if not full merging, between galaxies including quasar J0742+2704. There is evidence of a distorted tidal tail, or a streamer of gas, pulled out by the gravity of a nearby galaxy. Also, astronomers believe ring galaxies form when one galaxy passes through another, redistributing its contents into a central core circled by stars and gas. Image via NASA/ ESA/ Kristina Nyland (U.S. Naval Research Laboratory).
  • Hubble discovered a young quasar jet in a spiral galaxy.
  • Quasar jets are typically found in elliptical galaxies.
  • This discovery challenges the idea that quasars form only in merging galaxies.

Young quasar jet in spiral galaxy

The night sky has always played a crucial role in navigation, from early ocean crossings to modern GPS. Besides stars, the United States Navy uses quasars as beacons. Quasars are distant galaxies with supermassive black holes, surrounded by brilliant hot disks of swirling gas that can blast off jets of material.

Following up on the 2020 discovery of newborn jets in a number of quasars, Olivia Achenbach of the United States Naval Academy has used NASA’s Hubble Space Telescope to reveal surprising properties of one of them, quasar J0742+2704. Achenbach, who made the discovery a four-week internship, said:

The biggest surprise was seeing the distinct spiral shape in the Hubble Space Telescope images. At first, I was worried I had made an error.

Kristina Nyland of the Naval Research Laboratory, Achenbach’s adviser on the research, added:

We typically see quasars as older galaxies that have grown very massive, along with their central black holes, after going through messy mergers and have come out with an elliptical shape.

Typical quasar-hosting galaxies

Nyland also commented:

It’s extremely rare and exciting to find a quasar-hosting galaxy with spiral arms and a black hole that is more than 400 million times the mass of the sun — which is pretty big — plus young jets that weren’t detectable 20 years ago.

The unusual quasar takes its place amid an active debate in the astronomy community over what triggers quasar jets. It can be significant in the evolution of galaxies, as the jets can suppress star formation. Some astronomers suspect that quasar jets are triggered by major galaxy mergers. That when the material from two or more galaxies mashes together, and heated gas is funneled toward merged black holes. Spiral galaxy quasars like J0742+2704, however, suggest that there may be other pathways for jet formation.

While J0742+2704 has maintained its spiral shape, the Hubble image does show intriguing signs of its potential interaction with other galaxies. One of its arms shows distortion, possibly a tidal tail.

According to Nyland:

Clearly there is something interesting going on. While the quasar has not experienced a major disruptive merger, it may be interacting with another galaxy, which is gravitationally tugging at its spiral arm.

Another ring galaxy is nearby

Also another galaxy that appears nearby in the Hubble image (though its location still needs to be spectroscopically confirmed) has a ring structure. This rare shape can occur after a galaxy interaction in which a smaller galaxy punches through the center of a spiral galaxy. Nyland indicated:

The ring galaxy near the quasar host galaxy could be an intriguing clue as to what is happening in this system. We may be witnessing the aftermath of the interaction that triggered this young quasar jet.

Both Achenbach and Nyland emphasize that this intriguing discovery is really a new starting point, and there will be additional multi-wavelength analysis of J0742+2704 with data from NASA’s Chandra X-ray Observatory and the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile. It’s also a case for keeping our eyes on the skies. Achenbach concluded:

If we looked at this galaxy 20 years, or maybe even a decade ago, we would have seen a fairly average quasar and never known it would eventually be home to newborn jets. It goes to show that if you keep searching, you can find something remarkable that you never expected, and it can send you in a whole new direction of discovery.

Bottom line: A recent Hubble image reveals a spiral galaxy hosting quasar. Typically, quasars are older galaxies that have grown very massive and are not spiral shaped.

Via NASA

Read more: 1st pair of merging quasars seen at Cosmic Dawn

The post Surprising spiral galaxy hosting quasar jet first appeared on EarthSky.



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Spiral galaxy hosting quasar: Quasar-jet-in-spiral-galaxy-Jan-13-2025-Hubble
This image from the Hubble Space Telescope indicates a spiral galaxy hosting quasar. Hubble captured hints of interaction, if not full merging, between galaxies including quasar J0742+2704. There is evidence of a distorted tidal tail, or a streamer of gas, pulled out by the gravity of a nearby galaxy. Also, astronomers believe ring galaxies form when one galaxy passes through another, redistributing its contents into a central core circled by stars and gas. Image via NASA/ ESA/ Kristina Nyland (U.S. Naval Research Laboratory).
  • Hubble discovered a young quasar jet in a spiral galaxy.
  • Quasar jets are typically found in elliptical galaxies.
  • This discovery challenges the idea that quasars form only in merging galaxies.

Young quasar jet in spiral galaxy

The night sky has always played a crucial role in navigation, from early ocean crossings to modern GPS. Besides stars, the United States Navy uses quasars as beacons. Quasars are distant galaxies with supermassive black holes, surrounded by brilliant hot disks of swirling gas that can blast off jets of material.

Following up on the 2020 discovery of newborn jets in a number of quasars, Olivia Achenbach of the United States Naval Academy has used NASA’s Hubble Space Telescope to reveal surprising properties of one of them, quasar J0742+2704. Achenbach, who made the discovery a four-week internship, said:

The biggest surprise was seeing the distinct spiral shape in the Hubble Space Telescope images. At first, I was worried I had made an error.

Kristina Nyland of the Naval Research Laboratory, Achenbach’s adviser on the research, added:

We typically see quasars as older galaxies that have grown very massive, along with their central black holes, after going through messy mergers and have come out with an elliptical shape.

Typical quasar-hosting galaxies

Nyland also commented:

It’s extremely rare and exciting to find a quasar-hosting galaxy with spiral arms and a black hole that is more than 400 million times the mass of the sun — which is pretty big — plus young jets that weren’t detectable 20 years ago.

The unusual quasar takes its place amid an active debate in the astronomy community over what triggers quasar jets. It can be significant in the evolution of galaxies, as the jets can suppress star formation. Some astronomers suspect that quasar jets are triggered by major galaxy mergers. That when the material from two or more galaxies mashes together, and heated gas is funneled toward merged black holes. Spiral galaxy quasars like J0742+2704, however, suggest that there may be other pathways for jet formation.

While J0742+2704 has maintained its spiral shape, the Hubble image does show intriguing signs of its potential interaction with other galaxies. One of its arms shows distortion, possibly a tidal tail.

According to Nyland:

Clearly there is something interesting going on. While the quasar has not experienced a major disruptive merger, it may be interacting with another galaxy, which is gravitationally tugging at its spiral arm.

Another ring galaxy is nearby

Also another galaxy that appears nearby in the Hubble image (though its location still needs to be spectroscopically confirmed) has a ring structure. This rare shape can occur after a galaxy interaction in which a smaller galaxy punches through the center of a spiral galaxy. Nyland indicated:

The ring galaxy near the quasar host galaxy could be an intriguing clue as to what is happening in this system. We may be witnessing the aftermath of the interaction that triggered this young quasar jet.

Both Achenbach and Nyland emphasize that this intriguing discovery is really a new starting point, and there will be additional multi-wavelength analysis of J0742+2704 with data from NASA’s Chandra X-ray Observatory and the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile. It’s also a case for keeping our eyes on the skies. Achenbach concluded:

If we looked at this galaxy 20 years, or maybe even a decade ago, we would have seen a fairly average quasar and never known it would eventually be home to newborn jets. It goes to show that if you keep searching, you can find something remarkable that you never expected, and it can send you in a whole new direction of discovery.

Bottom line: A recent Hubble image reveals a spiral galaxy hosting quasar. Typically, quasars are older galaxies that have grown very massive and are not spiral shaped.

Via NASA

Read more: 1st pair of merging quasars seen at Cosmic Dawn

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January full moon is the Wolf Moon. See it near Mars!

Chart showing a white disk as the full moon. It lies next to a red dot representing Mars and below the white dots of the stars Castor and Pollux.
Everyone on Earth will see the full Wolf Moon on the night of January 13, 2025. And there’s a bonus! The January full moon will lie near the bright red planet Mars. Mars was closest to Earth for this 2-year period on January 12. And Mars will reach opposition on January 15-16. What’s more, a few lucky observers – in parts of North America, northwest Africa, the Azores and the Cape Verde Islands – will see the moon occult – or pass in front of – Mars. So if you look outside on the night of January 13 and don’t see Mars … that might be because it’s behind the moon! Find details on the occultation here. Look near the moon and Mars for Gemini’s twin stars, Castor and Pollux. Plus, the moon, Mars and twin stars will almost be in a straight line, and they’ll be visible all night. Chart via EarthSky.

When and where to look in 2025: Look for the bright, round full moon to rise in the east near sunset on January 13, 2025. It will be glowing nearly overhead around midnight, and dropping low in the west near sunrise. And that bright red star close to the moon is Mars. Mars it at its biggest and brightest for 2025 now!

Crest of the full moon falls at 22:27 UTC on January 13. That’s 4:27 p.m. CST.

Keep up with the moon phase every day of 2025 with the EarthSky Lunar Calendar. A unique and beautiful poster-sized calendar. Get yours today!

The full moon glows next to Mars

This year, the January full moon lies next to Mars, now at its brightest. The bright moonlight might make seeing Mars difficult. To help spot the red planet, block the right half of the full moon with a distant object such as a utility pole. Mars may very well pop into view. For a better view of the planet, come back a couple of nights later when a bright moon isn’t in the sky.

A few observers will see the moon occult – or pass in front of – Mars. If you look outside on the night of January 13 and don’t see Mars … that might be because it’s behind the moon. Visit In-the-Sky.org for more.

Chart showing large yellow disk for the sun, a blue disk for Earth, a small white dot for the moon, and a red disk for Mars all in a row.
On January 13, the full moon lies directly between Earth and Mars. Chart via EarthSky.

Even though the moon and Mars appear next to each other in the sky, they are in fact nowhere near each other in three-dimensional space. That’s because Mars, lying at 59 million miles from our planet, is about 240 times farther than the moon.

January’s full moon in front of the twin stars of Gemini

The January full moon can lie in front of one of two constellations of the zodiac. If the full moon falls in the first half of the month, as it does this year, it lands in Gemini the Twins. If it happens during the second half, as it did last year, it falls in Cancer the Crab.

The moon is roundest on the day when it is full, but it appears almost, but not quite full the day before and after. On the evening of this January’s full moon, the twin stars of Gemini, Castor (the dimmer one) and Pollux shine nearby, forming an almost straight line with the moon. However, the bright moonlight might make these two famous stars dim or even invisible. If you can’t spot them, rest assured, they are still there!

Chart showing an arrow passing a blue dot representing Earth then passing a white dot representing the moon in the direction in the sky as two white dots representing Castor and Pollux and a red dot representing Mars.
The January 2025 full moon occurs on the overnight of January 13 and lies in the constellation Gemini and in a line with its twin stars Castor and Pollux. Chart via EarthSky.

January’s full moon is the Wolf Moon

All full moons have popular nicknames. January’s full moon is often called the Wolf Moon because – in parts of the world where they live – wolves are active in January and often howl on cold nights. Other names derived from North American indigenous people also refer to January’s cold. They include the Cold Moon, Frost Exploding Moon, Freeze Up Moon, and Hard Moon.

Chart showing, all in a row, a large starred dot representing the sun, a blue dot representing Earth, and a white dot representing the moon.
At full moon, the sun, Earth, and moon are aligned in space, with Earth in the middle. The moon’s day side – its fully lighted hemisphere – directly faces us. Chart via EarthSky.

January full moon and the July sun

Every full moon stays – more or less – opposite the sun. The moon’s path roughly follows the sun’s daytime path from six months ago, and six months hence.

In the Northern Hemisphere, you can see this happening as you watch the January full moon rise to almost the top of the sky, just as the sun does in July.

Two charts: the one on the left shows two dashed lines, the higher one representing the path of the sun in July and and the lower dashed line in January. The one on the right shows two dashed lines, the higher one represtning the path of the full moon in January and the lower dashed line in July.
The high arc across the sky of the January full moon closely matches that of the July sun. The low arc of the January sun closely matches that of the July full moon. Chart via EarthSky.

For the Southern Hemisphere, it’s the same effect, but reversed. Since it’s early summer there, the full moon in January rides low in the sky as the January sun rides high.

Two charts: the one on the left shows two dashed lines, the higher one representing the path of the sun in January and and the lower dashed line in July. The one on the right shows two dashed lines, the higher one represtning the path of the full moon in July and the lower dashed line in January.
The high arc across the sky of the January full moon closely matches that of the July sun. The low arc of the January sun closely matches that of the July full moon. Chart via EarthSky.

Tracing the high path of the January full moon

You can experiment with the path of the sun and moon. Simply trace a line with your finger from east to west along a low arc above the southern horizon to emulate the sun’s January path. Then trace another path high overhead to emulate to the moon’s path in January. And you’ll see that the higher path will be much longer than the lower one.

The monthly paths come into balance

Little by little, we can watch the two paths come back into balance. Each moon until June, the full moon will cross the sky at a slightly lower arc than the previous month. After that, each successive full moon takes less time than the previous one to cross the sky. Since last month’s full moon was closest to the winter solstice, it rose the highest. At March’s full moon, which is near the Northern Hemisphere’s spring equinox, the two paths – of the moon and of the sun – will nearly be the same.

Then, near the June solstice, those of us in the Northern Hemisphere see the sun cross high overhead during the year’s longest days. And, during the short northern summer nights, we see the moon cross lower and spend less time in the sky.

And on the cycle goes.

Bottom line: The 2025 January full Wolf Moon falls on January 13 at 22:27 UTC (4:27 p.m. CST). It appears next to the planet Mars – at its brightest for 2025 – and lies in the constellation Gemini.

The post January full moon is the Wolf Moon. See it near Mars! first appeared on EarthSky.



from EarthSky https://ift.tt/if1sP4R
Chart showing a white disk as the full moon. It lies next to a red dot representing Mars and below the white dots of the stars Castor and Pollux.
Everyone on Earth will see the full Wolf Moon on the night of January 13, 2025. And there’s a bonus! The January full moon will lie near the bright red planet Mars. Mars was closest to Earth for this 2-year period on January 12. And Mars will reach opposition on January 15-16. What’s more, a few lucky observers – in parts of North America, northwest Africa, the Azores and the Cape Verde Islands – will see the moon occult – or pass in front of – Mars. So if you look outside on the night of January 13 and don’t see Mars … that might be because it’s behind the moon! Find details on the occultation here. Look near the moon and Mars for Gemini’s twin stars, Castor and Pollux. Plus, the moon, Mars and twin stars will almost be in a straight line, and they’ll be visible all night. Chart via EarthSky.

When and where to look in 2025: Look for the bright, round full moon to rise in the east near sunset on January 13, 2025. It will be glowing nearly overhead around midnight, and dropping low in the west near sunrise. And that bright red star close to the moon is Mars. Mars it at its biggest and brightest for 2025 now!

Crest of the full moon falls at 22:27 UTC on January 13. That’s 4:27 p.m. CST.

Keep up with the moon phase every day of 2025 with the EarthSky Lunar Calendar. A unique and beautiful poster-sized calendar. Get yours today!

The full moon glows next to Mars

This year, the January full moon lies next to Mars, now at its brightest. The bright moonlight might make seeing Mars difficult. To help spot the red planet, block the right half of the full moon with a distant object such as a utility pole. Mars may very well pop into view. For a better view of the planet, come back a couple of nights later when a bright moon isn’t in the sky.

A few observers will see the moon occult – or pass in front of – Mars. If you look outside on the night of January 13 and don’t see Mars … that might be because it’s behind the moon. Visit In-the-Sky.org for more.

Chart showing large yellow disk for the sun, a blue disk for Earth, a small white dot for the moon, and a red disk for Mars all in a row.
On January 13, the full moon lies directly between Earth and Mars. Chart via EarthSky.

Even though the moon and Mars appear next to each other in the sky, they are in fact nowhere near each other in three-dimensional space. That’s because Mars, lying at 59 million miles from our planet, is about 240 times farther than the moon.

January’s full moon in front of the twin stars of Gemini

The January full moon can lie in front of one of two constellations of the zodiac. If the full moon falls in the first half of the month, as it does this year, it lands in Gemini the Twins. If it happens during the second half, as it did last year, it falls in Cancer the Crab.

The moon is roundest on the day when it is full, but it appears almost, but not quite full the day before and after. On the evening of this January’s full moon, the twin stars of Gemini, Castor (the dimmer one) and Pollux shine nearby, forming an almost straight line with the moon. However, the bright moonlight might make these two famous stars dim or even invisible. If you can’t spot them, rest assured, they are still there!

Chart showing an arrow passing a blue dot representing Earth then passing a white dot representing the moon in the direction in the sky as two white dots representing Castor and Pollux and a red dot representing Mars.
The January 2025 full moon occurs on the overnight of January 13 and lies in the constellation Gemini and in a line with its twin stars Castor and Pollux. Chart via EarthSky.

January’s full moon is the Wolf Moon

All full moons have popular nicknames. January’s full moon is often called the Wolf Moon because – in parts of the world where they live – wolves are active in January and often howl on cold nights. Other names derived from North American indigenous people also refer to January’s cold. They include the Cold Moon, Frost Exploding Moon, Freeze Up Moon, and Hard Moon.

Chart showing, all in a row, a large starred dot representing the sun, a blue dot representing Earth, and a white dot representing the moon.
At full moon, the sun, Earth, and moon are aligned in space, with Earth in the middle. The moon’s day side – its fully lighted hemisphere – directly faces us. Chart via EarthSky.

January full moon and the July sun

Every full moon stays – more or less – opposite the sun. The moon’s path roughly follows the sun’s daytime path from six months ago, and six months hence.

In the Northern Hemisphere, you can see this happening as you watch the January full moon rise to almost the top of the sky, just as the sun does in July.

Two charts: the one on the left shows two dashed lines, the higher one representing the path of the sun in July and and the lower dashed line in January. The one on the right shows two dashed lines, the higher one represtning the path of the full moon in January and the lower dashed line in July.
The high arc across the sky of the January full moon closely matches that of the July sun. The low arc of the January sun closely matches that of the July full moon. Chart via EarthSky.

For the Southern Hemisphere, it’s the same effect, but reversed. Since it’s early summer there, the full moon in January rides low in the sky as the January sun rides high.

Two charts: the one on the left shows two dashed lines, the higher one representing the path of the sun in January and and the lower dashed line in July. The one on the right shows two dashed lines, the higher one represtning the path of the full moon in July and the lower dashed line in January.
The high arc across the sky of the January full moon closely matches that of the July sun. The low arc of the January sun closely matches that of the July full moon. Chart via EarthSky.

Tracing the high path of the January full moon

You can experiment with the path of the sun and moon. Simply trace a line with your finger from east to west along a low arc above the southern horizon to emulate the sun’s January path. Then trace another path high overhead to emulate to the moon’s path in January. And you’ll see that the higher path will be much longer than the lower one.

The monthly paths come into balance

Little by little, we can watch the two paths come back into balance. Each moon until June, the full moon will cross the sky at a slightly lower arc than the previous month. After that, each successive full moon takes less time than the previous one to cross the sky. Since last month’s full moon was closest to the winter solstice, it rose the highest. At March’s full moon, which is near the Northern Hemisphere’s spring equinox, the two paths – of the moon and of the sun – will nearly be the same.

Then, near the June solstice, those of us in the Northern Hemisphere see the sun cross high overhead during the year’s longest days. And, during the short northern summer nights, we see the moon cross lower and spend less time in the sky.

And on the cycle goes.

Bottom line: The 2025 January full Wolf Moon falls on January 13 at 22:27 UTC (4:27 p.m. CST). It appears next to the planet Mars – at its brightest for 2025 – and lies in the constellation Gemini.

The post January full moon is the Wolf Moon. See it near Mars! first appeared on EarthSky.



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Mars closest to Earth on January 12, 2025

The 2025 EarthSky Lunar Calendar is now available! A unique and beautiful poster-sized calendar. Get yours today!

Mars comes closest to Earth roughly every two years. Sometimes it’s closer than other times. Do you remember the historically close approach of Mars in 2003? At that time, Mars was closer than it had been in some 60,000 years. Mars was only slightly farther, but still very close, in 2018. At 14 UTC on January 12, 2025, Mars will be closest to Earth for its two-year period, but farther away than in 2003, 2018 or 2022. But not as far away as it’ll be in 2027.

On January 12, 2025, it’ll be 5.3 light-minutes away at a distance of 0.642 astronomical units (59.70 million miles or 96.08 million kilometers). Of course, these moments of closest approach are fleeting as both Earth and Mars move in their orbits around the sun.

Past and future Mars closest to Earth

Dates listed in UTC time.

  • At its August 27, 2003, close approach Mars was 34.65 million miles (55.76 million km) away.
  • At its July 31, 2018, close approach Mars was 35.78 million miles (57.59 million km) away.
  • At its December 1, 2022, close approach Mars was 50.61 million miles (81.45 million km) away.
  • At its January 12, 2025, close approach Mars will be 59.70 million miles (96.08 million km) away.
  • At its February 20, 2027, close approach Mars will be 63.01 million miles (101.41 million km) away.
  • At its March 29, 2029, close approach Mars will be 60.42 million miles (97.24 million km) away.

By the way, Mars won’t beat its 2003 performance until August 28, 2287, when the red planet will be 34.60 million miles (55.68 million km) away.

Read more: Chart showing Mars oppositions from 2018 to 2033

Planet with a big reddish area and dark swath in the middle and a white ice cap at the top.
View at EarthSky Community Photos. | B Martin in Riverside, California, captured this image of red Mars on December 15, 2024, just 1 month before Earth goes between the red planet and the sun, bringing Mars closest for this 2-year period. Martin wrote: “Mars was around maybe 45 degrees up. I saw it in live view, I knew it was a banger …” Thank you for sharing, B! January 12, 2025, finds Mars closest to Earth and then Mars will reach opposition – when Earth flies between it and the sun – on January 15-16.

January Charts for Mars

Have you seen Mars yet? You can spot it easily with the eye alone as the bright red “star” in the east every evening, and in the west before dawn. In fact, Mars is about the same brightness as Sirius, our brightest nighttime star. Only the planets Venus and Jupiter shine brighter than Mars in January 2025.

Chart showing a red dot for Mars moving to the upper right along a red line and past two white dots on the left for Castor and Pollux.
Mars is on display in January 2025 and closing in on the bright stars Castor and Pollux. It’ll be visible all night this month. Mars will be closest to Earth – about 5.3 light-minutes away – on January 12. And it’ll lie opposite the sun from Earth – or at opposition – on January 15-16. It’ll reach magnitude -1.4, matching that of Sirius, our brightest nighttime star. Mars is closest to Earth roughly every 2 years. So we won’t see Mars bright again until 2027.
Chart showing a white disk as the full moon. It lies next to a red dot representing Mars and below the white dots of the stars Castor and Pollux.
The full Wolf Moon will fall at 22:27 UTC (4:27 p.m. CST) on January 13, 2025, and will lie close to the red planet Mars. Observers in parts of North America, northwest Africa, Azores and Cape Verde Island will see the moon occult – or pass in front of – Mars at 4 UTC on December 14 (10 p.m. CST on December 13). Also nearby are Castor and Pollux, the twin stars of Gemini. Chart via EarthSky.
A white arrow pointing towards the lower left of a white disk and a small red dot.
Here’s a binocular view of the full moon approaching Mars, eventually passing in front of it, on the evening of January 13. Mars should be bright enough to spot in the glare of the moon. Chart via EarthSky.

Read more: Mars is racing toward opposition in January 2025: Start watching now!

Why aren’t we closest to Mars at its opposition?

If both the Earth and Mars circled the sun in perfect circles, and on the same exact plane, the distance between Earth and Mars would always be least on the day of Mars’ opposition. But we don’t live in such a symmetrical universe. All planets have elliptical orbits and a perihelion (closest point) and aphelion (farthest point) from the sun.

Mars’ orbit around the sun takes 687 days in contrast to 365 days for Earth. It has a year nearly twice as long as ours. Earth’s farthest point from the sun comes yearly in early July. Mars was at its closest to the sun for 2025 on January 1 and has been edging away from the sun each day. At the same time, Earth has been moving closer to the sun.

At its opposition on January 15-16 – when Earth will be directly between Mars and the sun – Mars will be farther from the sun than on January 12. On the other hand, Earth will be closer to the sun (and therefore farther from Mars) on January 15-16 than January 12. That all adds up to Earth being slightly closer to Mars on January 12 than January 15-16.

The time interval between a Mars opposition and its least distance from Earth can be as long as 8.5 days (1969), or as little as 10 minutes (2208 and 2232).

Generally speaking, Mars is at its brightest in 2025 throughout the month of January. It will be shining as bright as Sirius, the brightest star in the night sky.

Is Mars brightest when it’s closest?

Mars is not necessarily at its brightest when its closest to Earth. You might think Mars should be brighter when it’s closest to Earth on January 12 than at opposition on January 15-16. But it’s not.

Mars is a tiny bit fainter now than it will be at its January 15-16 opposition. That’s because of something known as opposition surge. Mars reflects sunlight most directly back to Earth at opposition. This directness accentuates Mars’ brilliance. Before and after opposition, sunlight is reflected at a slightly slanted angle relative to Earth, thereby reducing Mars’ brightness.

Earth swings between Mars and the sun every other year, at progressively later dates. Earth will next lap Mars on February 19-20, 2027. In the year 2027, Mars’ opposition comes on February 19, 2027, and Mars sweeps closest to Earth on February 20, 2027. At a distance of 63.01 million miles (101.41 million km), this will present Mars’ most distant opposition in the 21st century (2001 to 2100). Mars reaches aphelion – its farthest distance from the sun – on March 4, 2027. Its 2029 opposition will see Mars closer and brighter than in 2027 but its next closest and brightest opposition is September 2035.

Geocentric Ephemeris for Mars: 2025

Bottom line: The Mars opposition – when Earth flies between the sun and Mars – comes on January 15-16, 2025. But Mars and Earth are closest on January 12, 2025. You can easily see Mars with the eye alone. It looks like a bright red “star” in the east every evening, in the west before dawn.

The post Mars closest to Earth on January 12, 2025 first appeared on EarthSky.



from EarthSky https://ift.tt/5NgEdOi

The 2025 EarthSky Lunar Calendar is now available! A unique and beautiful poster-sized calendar. Get yours today!

Mars comes closest to Earth roughly every two years. Sometimes it’s closer than other times. Do you remember the historically close approach of Mars in 2003? At that time, Mars was closer than it had been in some 60,000 years. Mars was only slightly farther, but still very close, in 2018. At 14 UTC on January 12, 2025, Mars will be closest to Earth for its two-year period, but farther away than in 2003, 2018 or 2022. But not as far away as it’ll be in 2027.

On January 12, 2025, it’ll be 5.3 light-minutes away at a distance of 0.642 astronomical units (59.70 million miles or 96.08 million kilometers). Of course, these moments of closest approach are fleeting as both Earth and Mars move in their orbits around the sun.

Past and future Mars closest to Earth

Dates listed in UTC time.

  • At its August 27, 2003, close approach Mars was 34.65 million miles (55.76 million km) away.
  • At its July 31, 2018, close approach Mars was 35.78 million miles (57.59 million km) away.
  • At its December 1, 2022, close approach Mars was 50.61 million miles (81.45 million km) away.
  • At its January 12, 2025, close approach Mars will be 59.70 million miles (96.08 million km) away.
  • At its February 20, 2027, close approach Mars will be 63.01 million miles (101.41 million km) away.
  • At its March 29, 2029, close approach Mars will be 60.42 million miles (97.24 million km) away.

By the way, Mars won’t beat its 2003 performance until August 28, 2287, when the red planet will be 34.60 million miles (55.68 million km) away.

Read more: Chart showing Mars oppositions from 2018 to 2033

Planet with a big reddish area and dark swath in the middle and a white ice cap at the top.
View at EarthSky Community Photos. | B Martin in Riverside, California, captured this image of red Mars on December 15, 2024, just 1 month before Earth goes between the red planet and the sun, bringing Mars closest for this 2-year period. Martin wrote: “Mars was around maybe 45 degrees up. I saw it in live view, I knew it was a banger …” Thank you for sharing, B! January 12, 2025, finds Mars closest to Earth and then Mars will reach opposition – when Earth flies between it and the sun – on January 15-16.

January Charts for Mars

Have you seen Mars yet? You can spot it easily with the eye alone as the bright red “star” in the east every evening, and in the west before dawn. In fact, Mars is about the same brightness as Sirius, our brightest nighttime star. Only the planets Venus and Jupiter shine brighter than Mars in January 2025.

Chart showing a red dot for Mars moving to the upper right along a red line and past two white dots on the left for Castor and Pollux.
Mars is on display in January 2025 and closing in on the bright stars Castor and Pollux. It’ll be visible all night this month. Mars will be closest to Earth – about 5.3 light-minutes away – on January 12. And it’ll lie opposite the sun from Earth – or at opposition – on January 15-16. It’ll reach magnitude -1.4, matching that of Sirius, our brightest nighttime star. Mars is closest to Earth roughly every 2 years. So we won’t see Mars bright again until 2027.
Chart showing a white disk as the full moon. It lies next to a red dot representing Mars and below the white dots of the stars Castor and Pollux.
The full Wolf Moon will fall at 22:27 UTC (4:27 p.m. CST) on January 13, 2025, and will lie close to the red planet Mars. Observers in parts of North America, northwest Africa, Azores and Cape Verde Island will see the moon occult – or pass in front of – Mars at 4 UTC on December 14 (10 p.m. CST on December 13). Also nearby are Castor and Pollux, the twin stars of Gemini. Chart via EarthSky.
A white arrow pointing towards the lower left of a white disk and a small red dot.
Here’s a binocular view of the full moon approaching Mars, eventually passing in front of it, on the evening of January 13. Mars should be bright enough to spot in the glare of the moon. Chart via EarthSky.

Read more: Mars is racing toward opposition in January 2025: Start watching now!

Why aren’t we closest to Mars at its opposition?

If both the Earth and Mars circled the sun in perfect circles, and on the same exact plane, the distance between Earth and Mars would always be least on the day of Mars’ opposition. But we don’t live in such a symmetrical universe. All planets have elliptical orbits and a perihelion (closest point) and aphelion (farthest point) from the sun.

Mars’ orbit around the sun takes 687 days in contrast to 365 days for Earth. It has a year nearly twice as long as ours. Earth’s farthest point from the sun comes yearly in early July. Mars was at its closest to the sun for 2025 on January 1 and has been edging away from the sun each day. At the same time, Earth has been moving closer to the sun.

At its opposition on January 15-16 – when Earth will be directly between Mars and the sun – Mars will be farther from the sun than on January 12. On the other hand, Earth will be closer to the sun (and therefore farther from Mars) on January 15-16 than January 12. That all adds up to Earth being slightly closer to Mars on January 12 than January 15-16.

The time interval between a Mars opposition and its least distance from Earth can be as long as 8.5 days (1969), or as little as 10 minutes (2208 and 2232).

Generally speaking, Mars is at its brightest in 2025 throughout the month of January. It will be shining as bright as Sirius, the brightest star in the night sky.

Is Mars brightest when it’s closest?

Mars is not necessarily at its brightest when its closest to Earth. You might think Mars should be brighter when it’s closest to Earth on January 12 than at opposition on January 15-16. But it’s not.

Mars is a tiny bit fainter now than it will be at its January 15-16 opposition. That’s because of something known as opposition surge. Mars reflects sunlight most directly back to Earth at opposition. This directness accentuates Mars’ brilliance. Before and after opposition, sunlight is reflected at a slightly slanted angle relative to Earth, thereby reducing Mars’ brightness.

Earth swings between Mars and the sun every other year, at progressively later dates. Earth will next lap Mars on February 19-20, 2027. In the year 2027, Mars’ opposition comes on February 19, 2027, and Mars sweeps closest to Earth on February 20, 2027. At a distance of 63.01 million miles (101.41 million km), this will present Mars’ most distant opposition in the 21st century (2001 to 2100). Mars reaches aphelion – its farthest distance from the sun – on March 4, 2027. Its 2029 opposition will see Mars closer and brighter than in 2027 but its next closest and brightest opposition is September 2035.

Geocentric Ephemeris for Mars: 2025

Bottom line: The Mars opposition – when Earth flies between the sun and Mars – comes on January 15-16, 2025. But Mars and Earth are closest on January 12, 2025. You can easily see Mars with the eye alone. It looks like a bright red “star” in the east every evening, in the west before dawn.

The post Mars closest to Earth on January 12, 2025 first appeared on EarthSky.



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Citizen scientists provide insights to Jupiter’s clouds in new study

Citizen scientists provide insights: Large planet with various bands of colorful clouds going around it. Many intricate swirls and white ovals in the clouds, with a larger red oval in the upper right.
View larger. | NASA’s Juno spacecraft captured this stunning view of Jupiter and its bands of clouds. Scientists thought these clouds were made of ammonia. But now, in a new study, citizen scientists provide insights showing that’s not the case. Image via NASA/ JPL-Caltech/ SwRI/ MSSS/ Kevin M. Gill (CC BY 3.0).
  • What are Jupiter’s clouds made of? Until now, scientists thought they were composed of ammonia ice crystals.
  • But new observations from citizen scientists, working with professional astronomers, suggest the clouds are deeper in Jupiter’s atmosphere, where it’s too warm for ammonia.
  • So ammonium hydrosulfide and smog might instead be the primary ingredients of Jupiter’s clouds. These ingredients could also produce the distinct reddish and brownish colors in the clouds.

Even in a small telescope, you can see that Jupiter is wrapped in colorful bands of clouds. Scientists have long believed these clouds were composed of ammonia ice crystals. But a new study from citizen scientists and professional astronomers suggests the clouds are deeper in Jupiter’s atmosphere than previously realized, at a depth too warm for ammonia ice crystals. The University of Oxford in the U.K. led the new study, and the researchers said on January 6, 2025, that – instead of ammonia – Jupiter’s clouds are made of ammonium hydrosulfide and smog. These ingredients could produce the distinct reddish and brownish colors in the clouds.

The researchers published their peer-reviewed findings in the Journal of Geophysical Research – Planets (JGR Planets) on January 1, 2025.

2025 EarthSky lunar calendar is available now. A unique and beautiful poster-sized calendar with phases of the moon for every night of the year. Get yours today!

Mapping Jupiter’s clouds

Work by amateur astronomer and citizen scientist Steven Hill in Colorado inspired the new study. He devised a new way of mapping Jupiter’s clouds, using commercially-available telescopes and special color filters. His work revealed that even amateur astronomers could map the amount of ammonia in the clouds.

MUSE observations of Jupiter’s clouds

In the new follow-up study from the University of Oxford, Patrick Irwin used Hill’s method for his own observations of Jupiter. The research team used the Multi-Unit Spectroscopic Explorer (MUSE) instrument at the European Southern Observatory’s Very Large Telescope (VLT) in Chile. The paper stated:

In a recent paper, it has been shown that it is possible for backyard astronomers to make observations of Jupiter with three to four spectral filters that can be processed to map the abundance of ammonia in Jupiter’s atmosphere. Here we test the reliability of this filter-imaging technique by applying it to VLT/MUSE observations of Jupiter and show that the method yields surprisingly reliable results that agree closely with more sophisticated analyses of these observations, and which are also consistent with observations made at microwave wavelengths by Juno and the Very Large Array.

Spectroscopic analysis

MUSE uses spectroscopy – the study of the absorption and emission of light and other radiation by matter – to analyze its targets. On Jupiter, different gases show up at different wavelengths. The results indicated the clouds were, in fact, made of ammonium hydrosulfide and smog.

So, why aren’t the clouds made of ammonia? As noted, the temperature at the altitude of the clouds is too warm for ammonia to condense into ice crystal clouds. Likewise, when moist, ammonia-rich air rises upward, the ammonia is either destroyed or mixes with other photochemical products (created by the effects of light), ie. smog. This happens before ammonia ice particles can form and become clouds. The smoggy photochemicals also give the clouds their distinctive reddish and brownish colors.

There may still be smaller regions where the updrafts of ammonia are faster, allowing the ammonia ice particles to form. This includes smaller white clouds that spacecraft have seen floating above the main cloud deck below.

Long dark rounded cloud with lighter oval-shaped cloud next to it. Other clouds swirl between and around them like cream in coffee.
View larger. | Juno obtained this closeup view of storm clouds on Jupiter on November 29, 2021. Scientists still think that some smaller white higher-altitude clouds, like those above the oval at the bottom of the image, are composed of ammonia ice crystals. Image via NASA/ JPL-Caltech/ SwRI/ MSSS/ Kevin M. Gill (CC BY 3.0).

Previous hints

Astronomers saw hints of the ammonium hydrosulfide and smog before with MUSE, but they had not corroborated those results yet. The methods were too complex and only a few groups of astronomers in the world had access to the data.

But now, the new results matched those from Hill and his team. The new method is also simpler, faster and less expensive. Irwin said:

I am astonished that such a simple method is able to probe so deep in the atmosphere and demonstrate so clearly that the main clouds cannot be pure ammonia ice! These results show that an innovative amateur using a modern camera and special filters can open a new window on Jupiter’s atmosphere and contribute to understanding the nature of Jupiter’s long-mysterious clouds and how the atmosphere circulates.

Hill added:

I always like to push my observations to see what physical measurements I can make with modest, commercial equipment. The hope is that I can find new ways for amateurs to make useful contributions to professional work. But I certainly did not expect an outcome as productive as this project has been!’

Tracking weather changes on Jupiter

Both citizen scientists and other astronomers can also use the new maps to monitor weather changes in Jupiter’s turbulent atmosphere. This includes the main bands, large storms like the Great Red Spot and smaller eddies and storms. Co-author John Rogers from the British Astronomical Association said:

A special advantage of this technique is that it could be used frequently by amateurs to link visible weather changes on Jupiter to ammonia variations, which could be important ingredients in the weather.

In addition, Irwin and his colleagues found that Saturn’s clouds seem to be similar. Ammonia maps using MUSE and VLT produced similar results to those of Jupiter.

And in another citizen science project last year, citizen scientists helped the American Astronomical Society study storms in Jupiter’s atmosphere in Juno images.

Bottom line: Scientists thought Jupiter’s clouds were made of ammonia. But new observations by citizen scientists and other astronomers show that’s not the case.

Source: Clouds and Ammonia in the Atmospheres of Jupiter and Saturn Determined From a Band-Depth Analysis of VLT/MUSE Observations

Via University of Oxford

Read more: Citizen scientists study Jupiter’s storms using Juno images

Read more: Jupiter’s Great Red Spot wiggles like gelatin

The post Citizen scientists provide insights to Jupiter’s clouds in new study first appeared on EarthSky.



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Citizen scientists provide insights: Large planet with various bands of colorful clouds going around it. Many intricate swirls and white ovals in the clouds, with a larger red oval in the upper right.
View larger. | NASA’s Juno spacecraft captured this stunning view of Jupiter and its bands of clouds. Scientists thought these clouds were made of ammonia. But now, in a new study, citizen scientists provide insights showing that’s not the case. Image via NASA/ JPL-Caltech/ SwRI/ MSSS/ Kevin M. Gill (CC BY 3.0).
  • What are Jupiter’s clouds made of? Until now, scientists thought they were composed of ammonia ice crystals.
  • But new observations from citizen scientists, working with professional astronomers, suggest the clouds are deeper in Jupiter’s atmosphere, where it’s too warm for ammonia.
  • So ammonium hydrosulfide and smog might instead be the primary ingredients of Jupiter’s clouds. These ingredients could also produce the distinct reddish and brownish colors in the clouds.

Even in a small telescope, you can see that Jupiter is wrapped in colorful bands of clouds. Scientists have long believed these clouds were composed of ammonia ice crystals. But a new study from citizen scientists and professional astronomers suggests the clouds are deeper in Jupiter’s atmosphere than previously realized, at a depth too warm for ammonia ice crystals. The University of Oxford in the U.K. led the new study, and the researchers said on January 6, 2025, that – instead of ammonia – Jupiter’s clouds are made of ammonium hydrosulfide and smog. These ingredients could produce the distinct reddish and brownish colors in the clouds.

The researchers published their peer-reviewed findings in the Journal of Geophysical Research – Planets (JGR Planets) on January 1, 2025.

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Mapping Jupiter’s clouds

Work by amateur astronomer and citizen scientist Steven Hill in Colorado inspired the new study. He devised a new way of mapping Jupiter’s clouds, using commercially-available telescopes and special color filters. His work revealed that even amateur astronomers could map the amount of ammonia in the clouds.

MUSE observations of Jupiter’s clouds

In the new follow-up study from the University of Oxford, Patrick Irwin used Hill’s method for his own observations of Jupiter. The research team used the Multi-Unit Spectroscopic Explorer (MUSE) instrument at the European Southern Observatory’s Very Large Telescope (VLT) in Chile. The paper stated:

In a recent paper, it has been shown that it is possible for backyard astronomers to make observations of Jupiter with three to four spectral filters that can be processed to map the abundance of ammonia in Jupiter’s atmosphere. Here we test the reliability of this filter-imaging technique by applying it to VLT/MUSE observations of Jupiter and show that the method yields surprisingly reliable results that agree closely with more sophisticated analyses of these observations, and which are also consistent with observations made at microwave wavelengths by Juno and the Very Large Array.

Spectroscopic analysis

MUSE uses spectroscopy – the study of the absorption and emission of light and other radiation by matter – to analyze its targets. On Jupiter, different gases show up at different wavelengths. The results indicated the clouds were, in fact, made of ammonium hydrosulfide and smog.

So, why aren’t the clouds made of ammonia? As noted, the temperature at the altitude of the clouds is too warm for ammonia to condense into ice crystal clouds. Likewise, when moist, ammonia-rich air rises upward, the ammonia is either destroyed or mixes with other photochemical products (created by the effects of light), ie. smog. This happens before ammonia ice particles can form and become clouds. The smoggy photochemicals also give the clouds their distinctive reddish and brownish colors.

There may still be smaller regions where the updrafts of ammonia are faster, allowing the ammonia ice particles to form. This includes smaller white clouds that spacecraft have seen floating above the main cloud deck below.

Long dark rounded cloud with lighter oval-shaped cloud next to it. Other clouds swirl between and around them like cream in coffee.
View larger. | Juno obtained this closeup view of storm clouds on Jupiter on November 29, 2021. Scientists still think that some smaller white higher-altitude clouds, like those above the oval at the bottom of the image, are composed of ammonia ice crystals. Image via NASA/ JPL-Caltech/ SwRI/ MSSS/ Kevin M. Gill (CC BY 3.0).

Previous hints

Astronomers saw hints of the ammonium hydrosulfide and smog before with MUSE, but they had not corroborated those results yet. The methods were too complex and only a few groups of astronomers in the world had access to the data.

But now, the new results matched those from Hill and his team. The new method is also simpler, faster and less expensive. Irwin said:

I am astonished that such a simple method is able to probe so deep in the atmosphere and demonstrate so clearly that the main clouds cannot be pure ammonia ice! These results show that an innovative amateur using a modern camera and special filters can open a new window on Jupiter’s atmosphere and contribute to understanding the nature of Jupiter’s long-mysterious clouds and how the atmosphere circulates.

Hill added:

I always like to push my observations to see what physical measurements I can make with modest, commercial equipment. The hope is that I can find new ways for amateurs to make useful contributions to professional work. But I certainly did not expect an outcome as productive as this project has been!’

Tracking weather changes on Jupiter

Both citizen scientists and other astronomers can also use the new maps to monitor weather changes in Jupiter’s turbulent atmosphere. This includes the main bands, large storms like the Great Red Spot and smaller eddies and storms. Co-author John Rogers from the British Astronomical Association said:

A special advantage of this technique is that it could be used frequently by amateurs to link visible weather changes on Jupiter to ammonia variations, which could be important ingredients in the weather.

In addition, Irwin and his colleagues found that Saturn’s clouds seem to be similar. Ammonia maps using MUSE and VLT produced similar results to those of Jupiter.

And in another citizen science project last year, citizen scientists helped the American Astronomical Society study storms in Jupiter’s atmosphere in Juno images.

Bottom line: Scientists thought Jupiter’s clouds were made of ammonia. But new observations by citizen scientists and other astronomers show that’s not the case.

Source: Clouds and Ammonia in the Atmospheres of Jupiter and Saturn Determined From a Band-Depth Analysis of VLT/MUSE Observations

Via University of Oxford

Read more: Citizen scientists study Jupiter’s storms using Juno images

Read more: Jupiter’s Great Red Spot wiggles like gelatin

The post Citizen scientists provide insights to Jupiter’s clouds in new study first appeared on EarthSky.



from EarthSky https://ift.tt/Ro7DIAv
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