Comet Hale-Bopp closest to the sun 29 years ago today

Comet Hale-Bopp with its prominent dust (white) and plasma (blue) tails. Photo via E. Kolmhofer, H. Raab; Johannes-Kepler-Observatory/ Wikimedia Commons (CC BY-SA 3.0).

• Discovered by amateur astronomers: Comet Hale-Bopp was discovered on July 23, 1995, independently by Alan Hale and Thomas Bopp, two amateur astronomers.
• Many people saw it! Comet Hale-Bopp became one of the brightest comets seen from Earth in the 20th century. It reached peak brightness in April 1997 and was visible to the unaided eye for a record-breaking 18 months.
• Huge cometary nucleus: Comet Hale-Bopp’s nucleus, or icy core, was estimated to be about 25 miles (40 kilometers) in diameter, making it one of the largest cometary nuclei ever observed.

Science news, night sky events and beautiful photos, all in one place. Click here to subscribe to EarthSky’s free daily newsletter.

Remember Comet Hale-Bopp?

Twenty-nine years ago today – on April 1, 1997 – Comet Hale-Bopp reached its perihelion or closest point to the sun. It was slightly less than Earth’s distance from the sun at 0.9 astronomical units (AU). And it was bright, for a comet. Its brightness – though dispersed across a wider area than stars – exceeded that of any star in the sky except for Sirius, the sky’s brightest star.

Hale-Bopp is officially labeled C/1995 O1. It was one of the most-viewed comets in human history.

As seen from the Northern Hemisphere, Hale-Bopp was the brightest comet since Comet West, sometimes called the Great Comet of 1976. Hale-Bopp stayed visible with the unaided eye for a record of 18 months, twice as long as the previous record holder: the Great Comet of 1811. Some called Hale-Bopp the Great Comet of 1997 (although others disagreed that it met the criteria for a Great Comet).

One of the most-viewed comets ever

It attracted so many people not only because of its rarity and beauty, but also because it enabled people to jump – in their minds – back in time. Some 4,200 years ago, when Hale-Bopp last passed the Earth and sun, the Egyptian pyramids were newly being polished by sand, and the Epic of Gilgamesh, considered the first great work of Western literature, was not yet written.

Comet Hale-Bopp above the pyramids of Giza, Egypt, in 1997, accompanied by the moon, the stars of Taurus the Bull and Perseus the Hero, and the Pleiades Cluster. Image via John Goldsmith/ ESA.

Comet Hale-Bopp discovery

Comet Hale-Bopp was discovered on July 23, 1995, by two independently observing amateur astronomers: Alan Hale and Thomas Bopp. At that time, the comet was a whopping 7.2 AU from the sun, which made it the most distant comet to ever be discovered by amateurs until that time.

What made that discovery possible was that Hale-Bopp was so bright. It was literally a thousand times brighter than Comet Halley had been at that same distance. Halley, one of the most famous comets, had visited the inner solar system a decade earlier. It was clear that Hale-Bopp was a very special comet, because comets typically don’t shine so brightly when they are beyond Jupiter’s orbit.

There were a few reasons explaining the comet’s unusual brightness. The main one is the enormous size of its nucleus, or core. Most cometary nuclei are thought to be no more than about 10 miles (16 km) across. The nucleus of Hale-Bopp had a diameter estimated to be between 25 and 40 miles across (40-65 km).

Comet Hale-Bopp from Pazin, Croatia, seen near perihelion. The Andromeda Galaxy is faintly visible to the lower right of the comet. Image via Philipp Salzgeber/ Wikimedia Commons (CC BY-SA 2.0 AT).

The orbit of Comet Hale-Bopp

Giant Jupiter is thought to have affected this comet’s orbit. Calculations suggest that Hale-Bopp appeared in Earth’s skies roughly 4,200 years ago. Now, though, the comet’s orbit is shorter. Astronomers think that – on what might have been its first voyage around the sun thousands of years ago – the comet almost collided with Jupiter. It passed very close to Jupiter again in April 1996, shortening its orbital period even further. The comet’s current orbital period is about 2,530 Earth years.

No records have been found of the comet’s passage 4,200 years ago, but that does not mean none were made. It most likely means that none survived. Around 2213 B.C., when the comet was visible, civilizations had been using the sky to track seasonal changes and other phenomena for a long time. They could not have missed Hale-Bopp.

Thus, in a way, Hale-Bopp is like a clock measuring time in millennia. It reminds us of the progress humankind has made since its last visit. Imagine what the world will look like when Comet Hale-Bopp next crosses our skies, sometime around the year 4380.

Where is the comet now?

Comet Hale-Bopp is in the constellation Octans, with an estimated magnitude of +20.14. The comet is over 4,702,313,489 miles (7,567,640,000 km) distant from the sun. Check the current location at theskylive.com.

Bottom line: Comet Hale-Bopp was at its closest point to the sun 29 years ago today. It was widely seen from the Northern Hemisphere. When will we see it again?

Read more: When will this sungrazing comet – C/2026 A1 (MAPS) – get bright enough to see?

Read more: The best comets of 2026: Here’s what to watch for

The post Comet Hale-Bopp closest to the sun 29 years ago today first appeared on EarthSky.

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Comet Hale-Bopp with its prominent dust (white) and plasma (blue) tails. Photo via E. Kolmhofer, H. Raab; Johannes-Kepler-Observatory/ Wikimedia Commons (CC BY-SA 3.0).

• Discovered by amateur astronomers: Comet Hale-Bopp was discovered on July 23, 1995, independently by Alan Hale and Thomas Bopp, two amateur astronomers.
• Many people saw it! Comet Hale-Bopp became one of the brightest comets seen from Earth in the 20th century. It reached peak brightness in April 1997 and was visible to the unaided eye for a record-breaking 18 months.
• Huge cometary nucleus: Comet Hale-Bopp’s nucleus, or icy core, was estimated to be about 25 miles (40 kilometers) in diameter, making it one of the largest cometary nuclei ever observed.

Science news, night sky events and beautiful photos, all in one place. Click here to subscribe to EarthSky’s free daily newsletter.

Remember Comet Hale-Bopp?

Twenty-nine years ago today – on April 1, 1997 – Comet Hale-Bopp reached its perihelion or closest point to the sun. It was slightly less than Earth’s distance from the sun at 0.9 astronomical units (AU). And it was bright, for a comet. Its brightness – though dispersed across a wider area than stars – exceeded that of any star in the sky except for Sirius, the sky’s brightest star.

Hale-Bopp is officially labeled C/1995 O1. It was one of the most-viewed comets in human history.

As seen from the Northern Hemisphere, Hale-Bopp was the brightest comet since Comet West, sometimes called the Great Comet of 1976. Hale-Bopp stayed visible with the unaided eye for a record of 18 months, twice as long as the previous record holder: the Great Comet of 1811. Some called Hale-Bopp the Great Comet of 1997 (although others disagreed that it met the criteria for a Great Comet).

One of the most-viewed comets ever

It attracted so many people not only because of its rarity and beauty, but also because it enabled people to jump – in their minds – back in time. Some 4,200 years ago, when Hale-Bopp last passed the Earth and sun, the Egyptian pyramids were newly being polished by sand, and the Epic of Gilgamesh, considered the first great work of Western literature, was not yet written.

Comet Hale-Bopp above the pyramids of Giza, Egypt, in 1997, accompanied by the moon, the stars of Taurus the Bull and Perseus the Hero, and the Pleiades Cluster. Image via John Goldsmith/ ESA.

Comet Hale-Bopp discovery

Comet Hale-Bopp was discovered on July 23, 1995, by two independently observing amateur astronomers: Alan Hale and Thomas Bopp. At that time, the comet was a whopping 7.2 AU from the sun, which made it the most distant comet to ever be discovered by amateurs until that time.

What made that discovery possible was that Hale-Bopp was so bright. It was literally a thousand times brighter than Comet Halley had been at that same distance. Halley, one of the most famous comets, had visited the inner solar system a decade earlier. It was clear that Hale-Bopp was a very special comet, because comets typically don’t shine so brightly when they are beyond Jupiter’s orbit.

There were a few reasons explaining the comet’s unusual brightness. The main one is the enormous size of its nucleus, or core. Most cometary nuclei are thought to be no more than about 10 miles (16 km) across. The nucleus of Hale-Bopp had a diameter estimated to be between 25 and 40 miles across (40-65 km).

Comet Hale-Bopp from Pazin, Croatia, seen near perihelion. The Andromeda Galaxy is faintly visible to the lower right of the comet. Image via Philipp Salzgeber/ Wikimedia Commons (CC BY-SA 2.0 AT).

The orbit of Comet Hale-Bopp

Giant Jupiter is thought to have affected this comet’s orbit. Calculations suggest that Hale-Bopp appeared in Earth’s skies roughly 4,200 years ago. Now, though, the comet’s orbit is shorter. Astronomers think that – on what might have been its first voyage around the sun thousands of years ago – the comet almost collided with Jupiter. It passed very close to Jupiter again in April 1996, shortening its orbital period even further. The comet’s current orbital period is about 2,530 Earth years.

No records have been found of the comet’s passage 4,200 years ago, but that does not mean none were made. It most likely means that none survived. Around 2213 B.C., when the comet was visible, civilizations had been using the sky to track seasonal changes and other phenomena for a long time. They could not have missed Hale-Bopp.

Thus, in a way, Hale-Bopp is like a clock measuring time in millennia. It reminds us of the progress humankind has made since its last visit. Imagine what the world will look like when Comet Hale-Bopp next crosses our skies, sometime around the year 4380.

Where is the comet now?

Comet Hale-Bopp is in the constellation Octans, with an estimated magnitude of +20.14. The comet is over 4,702,313,489 miles (7,567,640,000 km) distant from the sun. Check the current location at theskylive.com.

Bottom line: Comet Hale-Bopp was at its closest point to the sun 29 years ago today. It was widely seen from the Northern Hemisphere. When will we see it again?

Read more: When will this sungrazing comet – C/2026 A1 (MAPS) – get bright enough to see?

Read more: The best comets of 2026: Here’s what to watch for

The post Comet Hale-Bopp closest to the sun 29 years ago today first appeared on EarthSky.

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The April birthstone is the diamond, the hardest known gem

The April birthstone is the diamond. And a diamond solitaire ring is a popular choice for engagement rings. Image via EarthSky’s Marcy Curran.

The April birthstone

The April birthstone is the diamond. It’s treasured for its exceptional hardness and purity of color. Although the diamond is not the rarest of gems, it’s still one of the most popular gemstones.

As a result of a diamonds’ cold, sparkling fire, it’s held us spellbound for centuries. What’s more, it’s inspired rich, passionate myths of romance, intrigue, power, greed and magic. Today, the diamond is a symbol of enduring love, and often graces engagement rings.

The science of diamonds

Ancient Hindus, finding diamonds washed out of the ground after thunderstorms, believed bolts of lightning created them.

Of course, we know different now. In fact, diamonds are the rich cousins of graphite. Both are crystalline forms of pure carbon. But the enormous differences in their properties are a result of the way the carbon atoms bond together. In graphite, carbon atoms form in sheets that easily slide past each other, which makes graphite ideal as a lubricant and, of course, as pencil lead. On the other hand, diamond crystals are a tight-fisted network of carbon atoms securely bound in four directions. Thus, diamonds are the hardest naturally-occurring substance in the world.

So to achieve such a compact and strongly-held network of carbon atoms, it’s believed that diamonds crystallized deep under the Earth’s surface. At these depths – 90 to 120 miles deep (145 – 193 km) – the proper conditions for the formation of diamonds exist. That’s because pressures are more than 65,000 times that of the atmosphere at the Earth’s surface, with temperatures exceeding 2,700 degrees Fahrenheit (1,500 degrees Celsius). And as a matter of fact, such pressures and temperatures are reproduced in laboratories successfully creating synthetic diamonds.

This is the typical shape of a rough diamond crystal. Its lustrous faces also indicate that this crystal is from a primary deposit. Image via Géry Parent/ Wikipedia (public domain).

The quality of diamonds

There are many kinds of diamonds: transparent, translucent, or opaque; ranging from colorless to sooty black, with many colors in between. Mostly transparent diamonds, those that are colorless or tinted, end up in jewelry. And then lower grade diamonds are for industrial use.

The color of a diamond depends on the kind of impurities embedded inside it. For example, yellow diamonds betray minute quantities of nitrogen, while boron imparts a bluish hue. As a matter of fact, some inclusions in diamonds have great scientific value. That’s because they are time capsules containing valuable information about conditions deep in the Earth’s upper mantle where diamonds form. Additionally, they offer clues to the formation and age of the diamond.

Different types of rough diamonds. Image via James St. John/ Wikipedia (CC BY 2.0).

Sources of the April birthstone

Diamonds are found in alluvial deposits or gravel swept away by streams, rivers, glaciers and ocean currents. Also, they are in sedimentary rock where gravel deposits and organic material are compressed into rock. Diamonds are in some samples of kimberlite, a type of volcanic rock first identified in Kimberley, South Africa. Also, the diamonds in kimberlite may be very old, perhaps as much as three billion years old. And even meteorites – bits of rocky space debris that land on Earth – often contain tiny flecks of diamonds.

Diamonds are crystals. Crystals are the ultimate form of symmetry in nature. Their shape reflects the internal orderly arrangement of atoms within the crystal. In diamonds, atoms of carbon are held tightly by covalent bonding, where two neighboring atoms share an electron, endowing the diamond crystal with great strength. But despite that hardness, diamonds can be cut with saws and polished with grinding wheels coated with tiny industrial diamond fragments. In their natural form, diamonds can appear quite unimpressive. But they are cut and polished by skilled craftsmen in a pattern that reflects and refracts the light among their facets to reveal the hidden beauty of the stone.

One of the most famous diamonds, the Hope Diamond, shown here in the National Museum of Natural History in Washington, D.C. Image via David Bjorgen/ Wikipedia (CC BY-SA 3.0).

Diamond lore

Some diamonds seem to have lived lives of their own. One legendary stone in the diamond hall of fame is the Koh-i-noor (“Mountain of Light”). The Koh-i-noor diamond is believed to be 5,000 years old, and was featured in the great Sanskrit epic The Mahabharata.

Originally owned by the Rajah of Malwa in India, the Koh-i-noor has since been a player in victories and defeats spanning India, Persia and Afghanistan. It was in the possession of the great Mogul dynasty from 1526 to 1739. Its owners included Shah Jehan, who built the Taj Mahal in memory of his queen Mumtaz. The Persian invader Nadir Shah briefly possessed it until his assassination in 1747. The jewel then fell into the hands of Afghan rulers who eventually surrendered it to the Rajah of Punjab, Ranjit Singh.

Two years after Ranjit Singh’s death in 1839, Punjab became part of India under British rule and they presented the stone to Queen Victoria. Then she had it cut from its original 187 carats to 108 carats to further enhance its beauty. After her death, the diamond became part of the British crown jewels. Queen Elizabeth (later the Queen Mother) wore it in her crown at her 1937 coronation. However, Camilla chose to wear another crown to Charles III’s coronation in 2023.

Find out about the birthstones for the other months of the year.

January birthstone
February birthstone
March birthstone
May birthstone
June birthstone
July birthstone
August birthstone
September birthstone
October birthstone
November birthstone
December birthstone

Bottom line: The April birthstone is the diamond. It is the hardest of the known gemstones and is a popular choice for engagement rings.

The post The April birthstone is the diamond, the hardest known gem first appeared on EarthSky.

from EarthSky https://ift.tt/2hW138K

The April birthstone is the diamond. And a diamond solitaire ring is a popular choice for engagement rings. Image via EarthSky’s Marcy Curran.

The April birthstone

The April birthstone is the diamond. It’s treasured for its exceptional hardness and purity of color. Although the diamond is not the rarest of gems, it’s still one of the most popular gemstones.

As a result of a diamonds’ cold, sparkling fire, it’s held us spellbound for centuries. What’s more, it’s inspired rich, passionate myths of romance, intrigue, power, greed and magic. Today, the diamond is a symbol of enduring love, and often graces engagement rings.

The science of diamonds

Ancient Hindus, finding diamonds washed out of the ground after thunderstorms, believed bolts of lightning created them.

Of course, we know different now. In fact, diamonds are the rich cousins of graphite. Both are crystalline forms of pure carbon. But the enormous differences in their properties are a result of the way the carbon atoms bond together. In graphite, carbon atoms form in sheets that easily slide past each other, which makes graphite ideal as a lubricant and, of course, as pencil lead. On the other hand, diamond crystals are a tight-fisted network of carbon atoms securely bound in four directions. Thus, diamonds are the hardest naturally-occurring substance in the world.

So to achieve such a compact and strongly-held network of carbon atoms, it’s believed that diamonds crystallized deep under the Earth’s surface. At these depths – 90 to 120 miles deep (145 – 193 km) – the proper conditions for the formation of diamonds exist. That’s because pressures are more than 65,000 times that of the atmosphere at the Earth’s surface, with temperatures exceeding 2,700 degrees Fahrenheit (1,500 degrees Celsius). And as a matter of fact, such pressures and temperatures are reproduced in laboratories successfully creating synthetic diamonds.

This is the typical shape of a rough diamond crystal. Its lustrous faces also indicate that this crystal is from a primary deposit. Image via Géry Parent/ Wikipedia (public domain).

The quality of diamonds

There are many kinds of diamonds: transparent, translucent, or opaque; ranging from colorless to sooty black, with many colors in between. Mostly transparent diamonds, those that are colorless or tinted, end up in jewelry. And then lower grade diamonds are for industrial use.

The color of a diamond depends on the kind of impurities embedded inside it. For example, yellow diamonds betray minute quantities of nitrogen, while boron imparts a bluish hue. As a matter of fact, some inclusions in diamonds have great scientific value. That’s because they are time capsules containing valuable information about conditions deep in the Earth’s upper mantle where diamonds form. Additionally, they offer clues to the formation and age of the diamond.

Different types of rough diamonds. Image via James St. John/ Wikipedia (CC BY 2.0).

Sources of the April birthstone

Diamonds are found in alluvial deposits or gravel swept away by streams, rivers, glaciers and ocean currents. Also, they are in sedimentary rock where gravel deposits and organic material are compressed into rock. Diamonds are in some samples of kimberlite, a type of volcanic rock first identified in Kimberley, South Africa. Also, the diamonds in kimberlite may be very old, perhaps as much as three billion years old. And even meteorites – bits of rocky space debris that land on Earth – often contain tiny flecks of diamonds.

Diamonds are crystals. Crystals are the ultimate form of symmetry in nature. Their shape reflects the internal orderly arrangement of atoms within the crystal. In diamonds, atoms of carbon are held tightly by covalent bonding, where two neighboring atoms share an electron, endowing the diamond crystal with great strength. But despite that hardness, diamonds can be cut with saws and polished with grinding wheels coated with tiny industrial diamond fragments. In their natural form, diamonds can appear quite unimpressive. But they are cut and polished by skilled craftsmen in a pattern that reflects and refracts the light among their facets to reveal the hidden beauty of the stone.

One of the most famous diamonds, the Hope Diamond, shown here in the National Museum of Natural History in Washington, D.C. Image via David Bjorgen/ Wikipedia (CC BY-SA 3.0).

Diamond lore

Some diamonds seem to have lived lives of their own. One legendary stone in the diamond hall of fame is the Koh-i-noor (“Mountain of Light”). The Koh-i-noor diamond is believed to be 5,000 years old, and was featured in the great Sanskrit epic The Mahabharata.

Originally owned by the Rajah of Malwa in India, the Koh-i-noor has since been a player in victories and defeats spanning India, Persia and Afghanistan. It was in the possession of the great Mogul dynasty from 1526 to 1739. Its owners included Shah Jehan, who built the Taj Mahal in memory of his queen Mumtaz. The Persian invader Nadir Shah briefly possessed it until his assassination in 1747. The jewel then fell into the hands of Afghan rulers who eventually surrendered it to the Rajah of Punjab, Ranjit Singh.

Two years after Ranjit Singh’s death in 1839, Punjab became part of India under British rule and they presented the stone to Queen Victoria. Then she had it cut from its original 187 carats to 108 carats to further enhance its beauty. After her death, the diamond became part of the British crown jewels. Queen Elizabeth (later the Queen Mother) wore it in her crown at her 1937 coronation. However, Camilla chose to wear another crown to Charles III’s coronation in 2023.

Find out about the birthstones for the other months of the year.

January birthstone
February birthstone
March birthstone
May birthstone
June birthstone
July birthstone
August birthstone
September birthstone
October birthstone
November birthstone
December birthstone

Bottom line: The April birthstone is the diamond. It is the hardest of the known gemstones and is a popular choice for engagement rings.

The post The April birthstone is the diamond, the hardest known gem first appeared on EarthSky.

from EarthSky https://ift.tt/2hW138K

Starlink satellite breaks up, scatters debris

Artist’s illustration showing a Starlink satellite orbiting Earth. Image via Wikideas1/ Wikimedia. CC BY 4.0.

Starlink satellite unexpectedly breaks up, scattering debris

A Starlink satellite unexpectedly broke up on March 29, 2026, while in orbit about 350 miles (560 km) above Earth. The satellite – numbered 34343 – had been in orbit for less than a year. It launched from Vandenberg Space Force Base in California on May 27, 2025. SpaceX said it is investigating the cause of the rapid unscheduled disassembly (RUD). It also claimed:

Latest analysis shows the event poses no new risk to the space station, its crew, or to the upcoming launch of NASA’s Artemis II mission.

Though not everyone is confident in this assessment.

Some debris from the Starlink breakup should fall back to Earth over the next few weeks. That’s according to LeoLabs, a company that uses global radar to track satellites and space debris in low-Earth orbit. Large, remaining pieces would not return for a few years, yet.

LeoLabs said the cause of the explosion was likely internal to the satellite and not a collision. If so, this raises many questions about the likelihood of this event recurring in any of the more than 10,000 Starlink satellites currently orbiting Earth. LeoLabs’ radar detected what it called:

… tens of objects in the vicinity of the satellite after the event.

And, in fact, LeoLabs compared the Sunday event to one that occurred back on December 17, 2025. On that date, Starlink satellite 35956 also experienced a RUD.

Unexpected debris in low-Earth orbit could collide with other satellites, setting of a chain reaction known as the Kessler syndrome.

LeoLabs detected a fragment creation event involving SpaceX Starlink 34343 on 29 March 2026.

Learn more. ?? pic.twitter.com/54FoV3s953

— LeoLabs (@LeoLabs_Space) March 30, 2026

On Sunday, March 29, Starlink satellite 34343 experienced an anomaly on-orbit, resulting in loss of communications with the satellite at ~560 km above Earth.

Latest analysis shows the event poses no new risk to the @Space_Station, its crew, or to the upcoming launch of NASA’s…

— Starlink (@Starlink) March 30, 2026

Launch of Artemis 2

Artemis 2 is scheduled to launch to the moon on April 1, 2026. It will be the first crewed mission to the moon in more than 50 years. Does the debris pose a threat to the astronauts? SpaceX says no, but others aren’t so sure.

Astrophysicist and space sustainability analyst Jonathan McDowell, formerly of the Harvard and Smithsonian Center for Astrophysics, told Scientific American:

I don’t see how the risks can be nil. They are low because all the debris is expected to reenter quickly. But I’d like to hear more about why they assess the risk to be zero.

And if these Starlinks have been breaking up due to an inherent design flaw, McDowell said:

then the risks go up, a lot.

McDowell added:

The hope is that SpaceX will identify the root cause and proactively retire any particular subset of satellites that are found to be at risk.

Bottom line: A SpaceX Starlink satellite unexpectedly broke up in low-Earth orbit on March 29, 2026. Will the debris impact Artemis 2 or the space station?

The post Starlink satellite breaks up, scatters debris first appeared on EarthSky.

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Artist’s illustration showing a Starlink satellite orbiting Earth. Image via Wikideas1/ Wikimedia. CC BY 4.0.

Starlink satellite unexpectedly breaks up, scattering debris

A Starlink satellite unexpectedly broke up on March 29, 2026, while in orbit about 350 miles (560 km) above Earth. The satellite – numbered 34343 – had been in orbit for less than a year. It launched from Vandenberg Space Force Base in California on May 27, 2025. SpaceX said it is investigating the cause of the rapid unscheduled disassembly (RUD). It also claimed:

Latest analysis shows the event poses no new risk to the space station, its crew, or to the upcoming launch of NASA’s Artemis II mission.

Though not everyone is confident in this assessment.

Some debris from the Starlink breakup should fall back to Earth over the next few weeks. That’s according to LeoLabs, a company that uses global radar to track satellites and space debris in low-Earth orbit. Large, remaining pieces would not return for a few years, yet.

LeoLabs said the cause of the explosion was likely internal to the satellite and not a collision. If so, this raises many questions about the likelihood of this event recurring in any of the more than 10,000 Starlink satellites currently orbiting Earth. LeoLabs’ radar detected what it called:

… tens of objects in the vicinity of the satellite after the event.

And, in fact, LeoLabs compared the Sunday event to one that occurred back on December 17, 2025. On that date, Starlink satellite 35956 also experienced a RUD.

Unexpected debris in low-Earth orbit could collide with other satellites, setting of a chain reaction known as the Kessler syndrome.

LeoLabs detected a fragment creation event involving SpaceX Starlink 34343 on 29 March 2026.

Learn more. ?? pic.twitter.com/54FoV3s953

— LeoLabs (@LeoLabs_Space) March 30, 2026

On Sunday, March 29, Starlink satellite 34343 experienced an anomaly on-orbit, resulting in loss of communications with the satellite at ~560 km above Earth.

Latest analysis shows the event poses no new risk to the @Space_Station, its crew, or to the upcoming launch of NASA’s…

— Starlink (@Starlink) March 30, 2026

Launch of Artemis 2

Artemis 2 is scheduled to launch to the moon on April 1, 2026. It will be the first crewed mission to the moon in more than 50 years. Does the debris pose a threat to the astronauts? SpaceX says no, but others aren’t so sure.

Astrophysicist and space sustainability analyst Jonathan McDowell, formerly of the Harvard and Smithsonian Center for Astrophysics, told Scientific American:

I don’t see how the risks can be nil. They are low because all the debris is expected to reenter quickly. But I’d like to hear more about why they assess the risk to be zero.

And if these Starlinks have been breaking up due to an inherent design flaw, McDowell said:

then the risks go up, a lot.

McDowell added:

The hope is that SpaceX will identify the root cause and proactively retire any particular subset of satellites that are found to be at risk.

Bottom line: A SpaceX Starlink satellite unexpectedly broke up in low-Earth orbit on March 29, 2026. Will the debris impact Artemis 2 or the space station?

The post Starlink satellite breaks up, scatters debris first appeared on EarthSky.

from EarthSky https://ift.tt/SBfGgoO

Feel awe over these national park timelapse videos

This is Giants of Yosemite, by Gavin Heffernan. Heffernan has shared 4 timelapse videos from U.S. national parks with EarthSky. They’re a part of his PARKLIGHT project, meant to inspire people to protect our parklands. See the other national park timelapse videos below.

Science news, night sky events and beautiful photos, all in one place. Click here to subscribe to EarthSky’s free daily newsletter.

Awe-inspiring national park timelapse videos

Watch Taurus the Bull rise above Half Dome in Yosemite. Gaze at the red-rock monoliths of Zion as day turns to night. See the Blood Moon eclipse over Joshua Tree. And witness a curious fox at Channel Islands. These national park timelapse videos celebrate the beauty of the U.S. national park system.

Gavin Heffernan is a dark-sky advocate who shot these timelapse videos. His new series PARKLIGHT focuses on the U.S. national parks. Heffernan hopes his videos will inspire people to support the parks.

Starstorm Zion

Heffernan told EarthSky:

The fun part about PARKLIGHT is that each park is a unique experience with its own character and personality. There are commonalities, but every shoot is a totally different adventure, which is a big part of the magic of the national parks. Every visitor’s experience is a unique journey they get to have in their own way. But I try my best to capture the essence of each place and how it made me feel while I was there: the suspense of a beautiful sunset leading into a mysterious night, the intensity of a violent thunderstorm over Zion, the peace and quiet of a serene stream, the howl of coyotes echoing across the canyons at Joshua Tree.

I’m hoping that sharing these experiences helps other people get excited about the parks and inspires them to plan their own visit or find ways to help out. But, truthfully, I also make them as postcards to myself, so I can look back years later and remember not just what these parks looked like, but more importantly, what the experience felt like.

This is Starstorm Zion, by Gavin Heffernan. In this timelapse, you’ll see day turn to night in Utah’s Zion National Park. Watch as the Pleiades star cluster appears above the red cliffs and the Milky Way arcs across the sky as planes zip by. A brief thunderstorm clouds out the stars with lightning flashes before the serene stars appear again.

Eclipse Joshua Tree

Heffernan described to EarthSky how the parks connect him with the night sky:

The beauty of long-exposure night sky photography is that it allows you to see more than you would with your unaided eye. So it enhances that magical, surreal feeling that I always get in these locations and really helps amplify how special they are. The parks aren’t just nature refuges, they’re gateways to the universe and the stars we’ve lost. The parks are portals to unlocking your imagination and getting more perspective on life … and what a miracle it is we’re even here in the first place.

With the rapid advance of urban light pollution across the continent and the world, the parks have never been more important than they are now. They’ve become true sanctuaries of the stars. So, because of that, the night sky is often a central piece of these shorts.

This is Eclipse Joshua Tree, by Gavin Heffernan. The pastels colors of a desert sunset lead into a lunar eclipse. The reddened moon floats behind spiky Joshua trees, then brightens once more as star trails imitate falling meteors.

Channel Light

Heffernan also captures his landscapes under the beauty of sunlight. The last video showcases a day at Channel Islands National Park off the coast of California.

This is Channel Light, by Gavin Heffernan. See the sunny beauty of Channel Islands National Park as waves lap against the shore. Hikers take in an observation point and a Santa Cruz Island fox chews at scraps. The wind ruffles grasses and branches in this peaceful landscape.

National park timelapse videos meant to inspire

Spending a lot of time in the national parks has also given Heffernan an appreciation for the rangers and park service. His appreciation of both the park and park workers runs deep. Heffernan told EarthSky:

Like a lot of things in life, some of the most important stuff is the easiest to take for granted. I think the national parks are a good example of this. Because of the timeless nature of these locations, they often seem invulnerable, or that they will take care of themselves somehow. Nature does do a lot of the work, but a few hours at any park makes it clear how crucial the NPS staff are to protect and preserve these locations, especially the most popular parks that receive such a heavy human footprint.

It’s a mutually beneficial symbiotic collaboration between humans and nature that really is beautiful to see. But it doesn’t happen without support. The inspiration for starting this project was the government shutdown that was putting an extreme strain on park workers and therefore the parks themselves. Even though that situation has somewhat resolved, the parks are still woefully underfunded and need constant attention and care. We can’t take them for granted, especially as the rest of the world gets covered in concrete and the skies are blown out with lights, pollution and endless satellites littering the night.

Gavin Heffernan is the creator behind the PARKLIGHT series. Image via Gavin Heffernan.

Bottom line: Enjoy four national park timelapse videos from Gavin Heffernan. The views include both starscapes and landscapes of Yosemite, Zion, Joshua Tree and Channel Islands.

Via Gavin Heffernan

Read more: Moonlight Mojave: The desert under starry skies

Read more: See the best Milky Way photos of 2025 here

The post Feel awe over these national park timelapse videos first appeared on EarthSky.

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This is Giants of Yosemite, by Gavin Heffernan. Heffernan has shared 4 timelapse videos from U.S. national parks with EarthSky. They’re a part of his PARKLIGHT project, meant to inspire people to protect our parklands. See the other national park timelapse videos below.

Science news, night sky events and beautiful photos, all in one place. Click here to subscribe to EarthSky’s free daily newsletter.

Awe-inspiring national park timelapse videos

Watch Taurus the Bull rise above Half Dome in Yosemite. Gaze at the red-rock monoliths of Zion as day turns to night. See the Blood Moon eclipse over Joshua Tree. And witness a curious fox at Channel Islands. These national park timelapse videos celebrate the beauty of the U.S. national park system.

Gavin Heffernan is a dark-sky advocate who shot these timelapse videos. His new series PARKLIGHT focuses on the U.S. national parks. Heffernan hopes his videos will inspire people to support the parks.

Starstorm Zion

Heffernan told EarthSky:

The fun part about PARKLIGHT is that each park is a unique experience with its own character and personality. There are commonalities, but every shoot is a totally different adventure, which is a big part of the magic of the national parks. Every visitor’s experience is a unique journey they get to have in their own way. But I try my best to capture the essence of each place and how it made me feel while I was there: the suspense of a beautiful sunset leading into a mysterious night, the intensity of a violent thunderstorm over Zion, the peace and quiet of a serene stream, the howl of coyotes echoing across the canyons at Joshua Tree.

I’m hoping that sharing these experiences helps other people get excited about the parks and inspires them to plan their own visit or find ways to help out. But, truthfully, I also make them as postcards to myself, so I can look back years later and remember not just what these parks looked like, but more importantly, what the experience felt like.

This is Starstorm Zion, by Gavin Heffernan. In this timelapse, you’ll see day turn to night in Utah’s Zion National Park. Watch as the Pleiades star cluster appears above the red cliffs and the Milky Way arcs across the sky as planes zip by. A brief thunderstorm clouds out the stars with lightning flashes before the serene stars appear again.

Eclipse Joshua Tree

Heffernan described to EarthSky how the parks connect him with the night sky:

The beauty of long-exposure night sky photography is that it allows you to see more than you would with your unaided eye. So it enhances that magical, surreal feeling that I always get in these locations and really helps amplify how special they are. The parks aren’t just nature refuges, they’re gateways to the universe and the stars we’ve lost. The parks are portals to unlocking your imagination and getting more perspective on life … and what a miracle it is we’re even here in the first place.

With the rapid advance of urban light pollution across the continent and the world, the parks have never been more important than they are now. They’ve become true sanctuaries of the stars. So, because of that, the night sky is often a central piece of these shorts.

This is Eclipse Joshua Tree, by Gavin Heffernan. The pastels colors of a desert sunset lead into a lunar eclipse. The reddened moon floats behind spiky Joshua trees, then brightens once more as star trails imitate falling meteors.

Channel Light

Heffernan also captures his landscapes under the beauty of sunlight. The last video showcases a day at Channel Islands National Park off the coast of California.

This is Channel Light, by Gavin Heffernan. See the sunny beauty of Channel Islands National Park as waves lap against the shore. Hikers take in an observation point and a Santa Cruz Island fox chews at scraps. The wind ruffles grasses and branches in this peaceful landscape.

National park timelapse videos meant to inspire

Spending a lot of time in the national parks has also given Heffernan an appreciation for the rangers and park service. His appreciation of both the park and park workers runs deep. Heffernan told EarthSky:

Like a lot of things in life, some of the most important stuff is the easiest to take for granted. I think the national parks are a good example of this. Because of the timeless nature of these locations, they often seem invulnerable, or that they will take care of themselves somehow. Nature does do a lot of the work, but a few hours at any park makes it clear how crucial the NPS staff are to protect and preserve these locations, especially the most popular parks that receive such a heavy human footprint.

It’s a mutually beneficial symbiotic collaboration between humans and nature that really is beautiful to see. But it doesn’t happen without support. The inspiration for starting this project was the government shutdown that was putting an extreme strain on park workers and therefore the parks themselves. Even though that situation has somewhat resolved, the parks are still woefully underfunded and need constant attention and care. We can’t take them for granted, especially as the rest of the world gets covered in concrete and the skies are blown out with lights, pollution and endless satellites littering the night.

Gavin Heffernan is the creator behind the PARKLIGHT series. Image via Gavin Heffernan.

Bottom line: Enjoy four national park timelapse videos from Gavin Heffernan. The views include both starscapes and landscapes of Yosemite, Zion, Joshua Tree and Channel Islands.

Via Gavin Heffernan

Read more: Moonlight Mojave: The desert under starry skies

Read more: See the best Milky Way photos of 2025 here

The post Feel awe over these national park timelapse videos first appeared on EarthSky.

from EarthSky https://ift.tt/mCTg94D

The Big and Little Dipper: How to find them in the spring

Look for the Big and Little Dipper high in the northern sky on spring evenings. This view is for the Northern Hemisphere. The 2 outer stars in the bowl of the Dipper point to Polaris, the North Star. Polaris marks the end of the handle of the Little Dipper. Chart via EarthSky.

The Big and Little Dipper

The Big Dipper is one of the easiest star patterns to locate in Earth’s sky. It’s visible just about every clear night in the Northern Hemisphere, looking like a big dot-to-dot of a kitchen ladle. As Earth spins, the Big Dipper and its sky neighbor, the Little Dipper, rotate around the North Star, also known as Polaris.

From the northern part of the Northern Hemisphere, the Big and Little Dippers are in the sky continuously. In fact, they are always above your horizon, circling endlessly around Polaris. So given an unobstructed horizon, latitudes north of the 35th parallel (the approximate location of the Mediterranean Sea, Tennessee’s southern border and Kyoto, Japan) can expect to see the Big Dipper at any hour of the night every day of the year.

As for the Little Dipper, it’s circumpolar – always above the horizon – as far south as the Tropic of Cancer (23.5 degrees north latitude).

If you can spot the Big Dipper, then you’re on your way to finding the Little Dipper and the North Star, Polaris, too.

The Big Dipper rotates around Polaris every night and changes by season

Just remember the old saying: spring up and fall down. So on spring and summer evenings in the Northern Hemisphere, the Big Dipper shines at its highest in the evening sky. Then, on autumn and winter evenings, the Big Dipper sweeps closer to the horizon.

This animation shows the Big Dipper by seasons from mid-northern latitudes. The Big Dipper is shown at the same time – mid-evening – on the days of the solstices and equinoxes. Charts via Stellarium. Animation by EarthSky. Used with permission.

Here’s how to find Polaris and the Little Dipper

Notice that the Big Dipper has two parts, a bowl and a handle. Next, look for the two outer stars in the bowl of the Big Dipper. They are called Dubhe and Merak, and they’re known as The Pointers. An imaginary line drawn between them points to Polaris, the North Star. Polaris marks the end of the Little Dipper’s Handle. So, once you have Polaris, you can find the Little Dipper, too … if your sky is dark enough.

So why isn’t the Little Dipper as easy to pick out as the Big Dipper? That’s because the stars between Polaris and the outer bowl stars – Kochab and Pherkad – are rather dim. As a matter of fact, you’ll need a dark country sky to see all seven of the Little Dipper’s stars.

The Big and Little Dippers are not constellations

Also, the Big Dipper isn’t a constellation. It’s an asterism, or noticeable pattern of stars. The Big Dipper is a clipped version of the constellation Ursa Major the Greater Bear. And the stars of the Big Dipper outline the Bear’s tail and hindquarters.

The Little Dipper is also an asterism. These stars belong to the constellation Ursa Minor the Little Bear.

The Big Dipper will change over time

Astronomers sometimes speak of the fixed stars, but the stars aren’t truly fixed. Stars move in space. Thus the star patterns that we see today as the Big and Little Dippers will, slowly but surely, drift apart over time.

But even 25,000 years from now, the Big Dipper pattern will look nearly the same as it does today. Astronomers have found that the stars of the Big Dipper (excepting the pointer star, Dubhe, and the handle star, Alkaid) belong to an association of stars known as the Ursa Major Moving Cluster. These stars, loosely bound by gravity, drift in the same direction in space.

In 100,000 years, this pattern of Big Dipper stars (minus Dubhe and Alkaid) will appear much as it does today! But there will be some differences, as illustrated in the video below:

Star lore behind the Big and Little Dipper

In the star lore of the Mi’kmaq nation in northern Canada, the Big Dipper is also associated with a bear, but with a twist. The Mi’kmaq see the bowl of the Big Dipper as a Celestial Bear, and the three stars of the handle as hunters chasing the Bear. In the Mi’kmaq tale of the Celestial Bear, in autumn the hunters finally catch up with the Bear, and it’s said that the blood from the Bear colors the autumn landscape

In another version of the story, the Celestial Bear hits its nose when coming down to Earth, with its bloody nose giving color to autumn leaves. When the Celestial Bear is seen right on the northern horizon on late fall and early winter evenings, it’s a sure sign that the hibernation season is upon us.

In ancient times, the Little Dipper formed the wings of the constellation Draco the Dragon. But when the seafaring Phoenicians met with the Greek astronomer Thales around 600 BCE, they showed him how to use the Little Dipper stars to navigate. Thereby, Thales clipped Draco’s wings, to create a constellation that gave Greek sailors a new way to steer by the stars.

In Thales’ day, the stars Kochab and Pherkad (rather than Polaris) marked the approximate direction of the north celestial pole. That’s the point in the sky that is directly above the Earth’s North Pole.

To this day, Kochab and Pherkad are still known as the Guardians of the Pole.

Bottom line: You can find the Big Dipper and Little Dipper in the northern sky at any time of year. On spring evenings, the Big Dipper is high in the sky. The North Star, Polaris, is located at the end of the Little Dipper’s handle.

The post The Big and Little Dipper: How to find them in the spring first appeared on EarthSky.

from EarthSky https://ift.tt/GKTZOFh

Look for the Big and Little Dipper high in the northern sky on spring evenings. This view is for the Northern Hemisphere. The 2 outer stars in the bowl of the Dipper point to Polaris, the North Star. Polaris marks the end of the handle of the Little Dipper. Chart via EarthSky.

The Big and Little Dipper

The Big Dipper is one of the easiest star patterns to locate in Earth’s sky. It’s visible just about every clear night in the Northern Hemisphere, looking like a big dot-to-dot of a kitchen ladle. As Earth spins, the Big Dipper and its sky neighbor, the Little Dipper, rotate around the North Star, also known as Polaris.

From the northern part of the Northern Hemisphere, the Big and Little Dippers are in the sky continuously. In fact, they are always above your horizon, circling endlessly around Polaris. So given an unobstructed horizon, latitudes north of the 35th parallel (the approximate location of the Mediterranean Sea, Tennessee’s southern border and Kyoto, Japan) can expect to see the Big Dipper at any hour of the night every day of the year.

As for the Little Dipper, it’s circumpolar – always above the horizon – as far south as the Tropic of Cancer (23.5 degrees north latitude).

If you can spot the Big Dipper, then you’re on your way to finding the Little Dipper and the North Star, Polaris, too.

The Big Dipper rotates around Polaris every night and changes by season

Just remember the old saying: spring up and fall down. So on spring and summer evenings in the Northern Hemisphere, the Big Dipper shines at its highest in the evening sky. Then, on autumn and winter evenings, the Big Dipper sweeps closer to the horizon.

This animation shows the Big Dipper by seasons from mid-northern latitudes. The Big Dipper is shown at the same time – mid-evening – on the days of the solstices and equinoxes. Charts via Stellarium. Animation by EarthSky. Used with permission.

Here’s how to find Polaris and the Little Dipper

Notice that the Big Dipper has two parts, a bowl and a handle. Next, look for the two outer stars in the bowl of the Big Dipper. They are called Dubhe and Merak, and they’re known as The Pointers. An imaginary line drawn between them points to Polaris, the North Star. Polaris marks the end of the Little Dipper’s Handle. So, once you have Polaris, you can find the Little Dipper, too … if your sky is dark enough.

So why isn’t the Little Dipper as easy to pick out as the Big Dipper? That’s because the stars between Polaris and the outer bowl stars – Kochab and Pherkad – are rather dim. As a matter of fact, you’ll need a dark country sky to see all seven of the Little Dipper’s stars.

The Big and Little Dippers are not constellations

Also, the Big Dipper isn’t a constellation. It’s an asterism, or noticeable pattern of stars. The Big Dipper is a clipped version of the constellation Ursa Major the Greater Bear. And the stars of the Big Dipper outline the Bear’s tail and hindquarters.

The Little Dipper is also an asterism. These stars belong to the constellation Ursa Minor the Little Bear.

The Big Dipper will change over time

Astronomers sometimes speak of the fixed stars, but the stars aren’t truly fixed. Stars move in space. Thus the star patterns that we see today as the Big and Little Dippers will, slowly but surely, drift apart over time.

But even 25,000 years from now, the Big Dipper pattern will look nearly the same as it does today. Astronomers have found that the stars of the Big Dipper (excepting the pointer star, Dubhe, and the handle star, Alkaid) belong to an association of stars known as the Ursa Major Moving Cluster. These stars, loosely bound by gravity, drift in the same direction in space.

In 100,000 years, this pattern of Big Dipper stars (minus Dubhe and Alkaid) will appear much as it does today! But there will be some differences, as illustrated in the video below:

Star lore behind the Big and Little Dipper

In the star lore of the Mi’kmaq nation in northern Canada, the Big Dipper is also associated with a bear, but with a twist. The Mi’kmaq see the bowl of the Big Dipper as a Celestial Bear, and the three stars of the handle as hunters chasing the Bear. In the Mi’kmaq tale of the Celestial Bear, in autumn the hunters finally catch up with the Bear, and it’s said that the blood from the Bear colors the autumn landscape

In another version of the story, the Celestial Bear hits its nose when coming down to Earth, with its bloody nose giving color to autumn leaves. When the Celestial Bear is seen right on the northern horizon on late fall and early winter evenings, it’s a sure sign that the hibernation season is upon us.

In ancient times, the Little Dipper formed the wings of the constellation Draco the Dragon. But when the seafaring Phoenicians met with the Greek astronomer Thales around 600 BCE, they showed him how to use the Little Dipper stars to navigate. Thereby, Thales clipped Draco’s wings, to create a constellation that gave Greek sailors a new way to steer by the stars.

In Thales’ day, the stars Kochab and Pherkad (rather than Polaris) marked the approximate direction of the north celestial pole. That’s the point in the sky that is directly above the Earth’s North Pole.

To this day, Kochab and Pherkad are still known as the Guardians of the Pole.

Bottom line: You can find the Big Dipper and Little Dipper in the northern sky at any time of year. On spring evenings, the Big Dipper is high in the sky. The North Star, Polaris, is located at the end of the Little Dipper’s handle.

The post The Big and Little Dipper: How to find them in the spring first appeared on EarthSky.

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Can animals sense earthquakes? Science investigates

Can animals sense earthquakes? For years there have been reports of animals acting differently leading up to earthquakes. Science investigates. Image via vizslafotozas/ Pixabay.

• Some animals show unusual behavior before earthquakes. Are they sensing subtle signals such as vibrations, gas releases or electrical changes?
• Scientific evidence is inconsistent, and no behavior pattern reliably predicts when or where a quake will strike.
• Researchers continue studying animal behavior. In the meantime, modern detection continues to rely on instruments.

By Rachel Grant, London South Bank University

You deserve a daily dose of good news. For the latest in science and the night sky, click here to subscribe to our free daily newsletter.

Can animals sense earthquakes?

For centuries, people around the world have reported unusual animal behavior before earthquakes. Observations included livestock becoming restless, wildlife disappearing and snakes emerging from hibernation in the middle of winter. For a long time, scientists dismissed such observations as folklore.

In recent years, however, systematic research has begun to explore whether animals genuinely respond to environmental changes preceding major earthquakes. Although earthquakes are hard to predict even for humans, several studies suggest intriguing patterns in animal behavior before seismic events.

As the world population increases, more people will be affected when earthquakes happen, making this research more important than ever.

Observations of when animals sense earthquakes

My own research journey began with a serendipitous observation in Italy. I was studying the effects of moon phases on toad reproduction at San Ruffino Lake in 2009, when the toads disappeared for five days. They returned only after a magnitude 6.3 earthquake struck the city of L’Aquila, about 50 miles (80 km) away.

This observation formed the basis of my 2010 study. My study showed that 96% of common toads abandoned their breeding site five days before the 2009 L’Aquila earthquake. It was one of the first studies to quantify a shift in wild amphibian behavior before seismic activity. Amphibians’ permeable skin makes them especially sensitive to changes in water chemistry. And that could make their behavior a potential early warning of seismic activity.

Animal activity before an earthquake

I also conducted a multi-species study of Yanachaga National Park, Peru, before a major earthquake in 2011. A charity called Wildlife Insights (formerly Team Network) places cameras in many locations in national parks for conservation monitoring. I looked for parks where a large earthquake had occurred. Then I analyzed the charity’s photographs for Yanachaga National Park.

The motion-activated cameras recorded a sharp decline in animal activity in the weeks leading up to the quake. Daily counts fell from typical values of around five to 15 separate animal records per day to fewer than five. This was across all seven orders of vertebrates in the forest. In the final 24 hours before the quake, animal movements completely ceased.

I compared records from around the time of the earthquake to seismically quiet periods in the same season. I found that during less seismically active times, animal numbers stayed constant.

In Peru, the steep decline in activity was pronounced not only in small- and medium-sized rodents such as pacas and capybaras. But activity also declined in bigger animals like long-nosed armadillos. This “silencing” of the forest suggests that earthquake-related cues affect entire animal communities rather than just one species.

It’s not just wildlife

Research has shown that livestock around the world, particularly cows, also show signs of pre-seismic behavioral and physiological change.

There are numerous reports of cows panicking and wandering around in areas where they would not normally be seen. For example, there are stories that cows converged on San Francisco’s Chinatown in 1906 prior to a large earthquake that killed 3,000 people. In 2012, a blog post circulated on the internet showing photographs of cows entering a suburb of Malaysia’s capital city, Kuala Lumpur, and feeding in gardens, two days prior to a magnitude 8.6 earthquake off the coast of Sumatra.

Several Japanese studies have monitored dairy cows using automated milking and activity systems. These studies have reported modest but statistically significant reductions in milk yield and changes in rumination or restlessness in the days preceding some local earthquakes.

Cows’ behavior changes before an earthquake. Image via JanTemmel/ Pixabay.

Your pets may react, too

Pets seem to be affected too. In 2011, a massive magnitude 9.1 earthquake struck off the northeast coast of Honshu in Japan. It generated a tsunami that disabled three nuclear reactors. Post-earthquake questionnaires surveyed 1,259 dog owners and 703 cat owners about their pets’ behavior before the earthquake. About 19% of dog owners and 16% of cat owners reported unusual behavior. Restiveness was a dominant behavior in both species, usually within one day prior to the quake.

It’s important to note though, that post-event recollections are not considered as scientifically robust as data collected in real time.

It seems that pets might react differently before an earthquake, too. Image via miezekieze/ Pixabay.

What might animals be sensing?

The key question is not whether animals behave differently, but why.

One leading hypothesis, proposed by Friedemann Freund (a scientist for NASA), focuses on environmental changes. These changes are caused by stress building up in rocks as tectonic plates shift, prior to large earthquakes, releasing electrically charged particles.

These particles can alter the properties of air and soil in the area by increasing the number of positive airborne ions (electrically charged molecules). And they appear to affect stress levels and behavior in animals (including humans). More research is needed. But the phenomenon may help explain the changes in animal behavior before the Italian and Peruvian earthquakes.

However, there are many other cues that could contribute to unusual animal behavior before earthquakes. Some examples are vibrations, disturbances to the local electromagnetic field or sounds outside of human hearing range. We still don’t know exactly which signals, or combination of cues, explain the behavior.

Despite growing evidence that animals can sense environmental changes preceding earthquakes, the scientific community remains cautious. Several studies have found unusual animal behavior before earthquakes could later be explained by normal seasonal activity.

Then there’s the fact that earthquakes are rare, which makes the phenomenon difficult to study. I believe animals simply move away from unpleasant or unusual environmental changes, rather than “predicting” earthquakes.

Of ants and earthquakes

There are ongoing studies that may help us learn more about animal behavior and earthquakes. A systematic trial called Animal Alerts is underway in Lima, Peru, an area with a high level of seismic activity. Researchers have fitted dogs with smart collars that record their heart rate, movement and other parameters in real time.

A 2013 study carried out long-term observations of red wood ant mounds on active faults (cracks in the Earth’s crust that have recently moved and may cause earthquakes). The researchers reported alterations in daily activity rhythms of the ants living on these fault lines. Building on this work, my postgraduate research student, Shanza, is studying earthquake precursors for her master’s degree. She aims to identify which animal species are most likely to respond to early earthquake signals such as positive ions or magnetic field fluctuations. She then plans to simulate some of these conditions in the lab, using ants as a model species.

Animal data alone are unlikely to give reliable earthquake warnings. But the more we can combine animal data with environmental measurements, the closer we will come to reliable forecasts of earthquake hazard risk.

Rachel Grant, Senior Lecturer in Bioscience, London South Bank University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Bottom line: For years there have been reports that animals sense earthquakes as they change their behavior before the ground rocks. Science takes a look at this behavior.

The post Can animals sense earthquakes? Science investigates first appeared on EarthSky.

from EarthSky https://ift.tt/1m6NGxv

Can animals sense earthquakes? For years there have been reports of animals acting differently leading up to earthquakes. Science investigates. Image via vizslafotozas/ Pixabay.

• Some animals show unusual behavior before earthquakes. Are they sensing subtle signals such as vibrations, gas releases or electrical changes?
• Scientific evidence is inconsistent, and no behavior pattern reliably predicts when or where a quake will strike.
• Researchers continue studying animal behavior. In the meantime, modern detection continues to rely on instruments.

By Rachel Grant, London South Bank University

You deserve a daily dose of good news. For the latest in science and the night sky, click here to subscribe to our free daily newsletter.

Can animals sense earthquakes?

For centuries, people around the world have reported unusual animal behavior before earthquakes. Observations included livestock becoming restless, wildlife disappearing and snakes emerging from hibernation in the middle of winter. For a long time, scientists dismissed such observations as folklore.

In recent years, however, systematic research has begun to explore whether animals genuinely respond to environmental changes preceding major earthquakes. Although earthquakes are hard to predict even for humans, several studies suggest intriguing patterns in animal behavior before seismic events.

As the world population increases, more people will be affected when earthquakes happen, making this research more important than ever.

Observations of when animals sense earthquakes

My own research journey began with a serendipitous observation in Italy. I was studying the effects of moon phases on toad reproduction at San Ruffino Lake in 2009, when the toads disappeared for five days. They returned only after a magnitude 6.3 earthquake struck the city of L’Aquila, about 50 miles (80 km) away.

This observation formed the basis of my 2010 study. My study showed that 96% of common toads abandoned their breeding site five days before the 2009 L’Aquila earthquake. It was one of the first studies to quantify a shift in wild amphibian behavior before seismic activity. Amphibians’ permeable skin makes them especially sensitive to changes in water chemistry. And that could make their behavior a potential early warning of seismic activity.

Animal activity before an earthquake

I also conducted a multi-species study of Yanachaga National Park, Peru, before a major earthquake in 2011. A charity called Wildlife Insights (formerly Team Network) places cameras in many locations in national parks for conservation monitoring. I looked for parks where a large earthquake had occurred. Then I analyzed the charity’s photographs for Yanachaga National Park.

The motion-activated cameras recorded a sharp decline in animal activity in the weeks leading up to the quake. Daily counts fell from typical values of around five to 15 separate animal records per day to fewer than five. This was across all seven orders of vertebrates in the forest. In the final 24 hours before the quake, animal movements completely ceased.

I compared records from around the time of the earthquake to seismically quiet periods in the same season. I found that during less seismically active times, animal numbers stayed constant.

In Peru, the steep decline in activity was pronounced not only in small- and medium-sized rodents such as pacas and capybaras. But activity also declined in bigger animals like long-nosed armadillos. This “silencing” of the forest suggests that earthquake-related cues affect entire animal communities rather than just one species.

It’s not just wildlife

Research has shown that livestock around the world, particularly cows, also show signs of pre-seismic behavioral and physiological change.

There are numerous reports of cows panicking and wandering around in areas where they would not normally be seen. For example, there are stories that cows converged on San Francisco’s Chinatown in 1906 prior to a large earthquake that killed 3,000 people. In 2012, a blog post circulated on the internet showing photographs of cows entering a suburb of Malaysia’s capital city, Kuala Lumpur, and feeding in gardens, two days prior to a magnitude 8.6 earthquake off the coast of Sumatra.

Several Japanese studies have monitored dairy cows using automated milking and activity systems. These studies have reported modest but statistically significant reductions in milk yield and changes in rumination or restlessness in the days preceding some local earthquakes.

Cows’ behavior changes before an earthquake. Image via JanTemmel/ Pixabay.

Your pets may react, too

Pets seem to be affected too. In 2011, a massive magnitude 9.1 earthquake struck off the northeast coast of Honshu in Japan. It generated a tsunami that disabled three nuclear reactors. Post-earthquake questionnaires surveyed 1,259 dog owners and 703 cat owners about their pets’ behavior before the earthquake. About 19% of dog owners and 16% of cat owners reported unusual behavior. Restiveness was a dominant behavior in both species, usually within one day prior to the quake.

It’s important to note though, that post-event recollections are not considered as scientifically robust as data collected in real time.

It seems that pets might react differently before an earthquake, too. Image via miezekieze/ Pixabay.

What might animals be sensing?

The key question is not whether animals behave differently, but why.

One leading hypothesis, proposed by Friedemann Freund (a scientist for NASA), focuses on environmental changes. These changes are caused by stress building up in rocks as tectonic plates shift, prior to large earthquakes, releasing electrically charged particles.

These particles can alter the properties of air and soil in the area by increasing the number of positive airborne ions (electrically charged molecules). And they appear to affect stress levels and behavior in animals (including humans). More research is needed. But the phenomenon may help explain the changes in animal behavior before the Italian and Peruvian earthquakes.

However, there are many other cues that could contribute to unusual animal behavior before earthquakes. Some examples are vibrations, disturbances to the local electromagnetic field or sounds outside of human hearing range. We still don’t know exactly which signals, or combination of cues, explain the behavior.

Despite growing evidence that animals can sense environmental changes preceding earthquakes, the scientific community remains cautious. Several studies have found unusual animal behavior before earthquakes could later be explained by normal seasonal activity.

Then there’s the fact that earthquakes are rare, which makes the phenomenon difficult to study. I believe animals simply move away from unpleasant or unusual environmental changes, rather than “predicting” earthquakes.

Of ants and earthquakes

There are ongoing studies that may help us learn more about animal behavior and earthquakes. A systematic trial called Animal Alerts is underway in Lima, Peru, an area with a high level of seismic activity. Researchers have fitted dogs with smart collars that record their heart rate, movement and other parameters in real time.

A 2013 study carried out long-term observations of red wood ant mounds on active faults (cracks in the Earth’s crust that have recently moved and may cause earthquakes). The researchers reported alterations in daily activity rhythms of the ants living on these fault lines. Building on this work, my postgraduate research student, Shanza, is studying earthquake precursors for her master’s degree. She aims to identify which animal species are most likely to respond to early earthquake signals such as positive ions or magnetic field fluctuations. She then plans to simulate some of these conditions in the lab, using ants as a model species.

Animal data alone are unlikely to give reliable earthquake warnings. But the more we can combine animal data with environmental measurements, the closer we will come to reliable forecasts of earthquake hazard risk.

Rachel Grant, Senior Lecturer in Bioscience, London South Bank University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Bottom line: For years there have been reports that animals sense earthquakes as they change their behavior before the ground rocks. Science takes a look at this behavior.

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Lonely Alphard is the brightest star in Hydra

On northern spring evenings – and southern autumn evenings – you’ll find Hydra the Water Snake ascending in the east. It is the longest constellation in the sky. And it isn’t fully up until late evenings in April for the Northern Hemisphere. Alphard – sometimes called Cor Hydrae or Hydra’s Heart – is the brightest star in Hydra. Photo copyright by Till Credner/ AlltheSky.com/ Wikimedia Commons (CC BY-SA 3.0).

Alphard (Alpha Hydrae) is the brightest star in the largest constellation in the sky, Hydra the Water Snake. Despite its long length, Hydra’s stars are mostly dim except for Alphard. You will need a very dark sky to see them. Meanwhile, Alphard shines at 2nd magnitude. So it’s about as bright as the stars of the Big Dipper.

Known as the Heart of the Snake, Alphard is a precursor of spring for us in the Northern Hemisphere.

Alphard brings a new season

Alphard’s warm orange color and location in the constellation’s core makes it a good representative for the Snake’s Heart. There is something about Alphard – some combination of its orange color and not-too-showy brightness – that looks friendly.

Like so many skywatchers before you, you’ll love seeing Alphard ascend in the early evening in late February and March as it ushers in a new season. Alphard is located in the upper part of the Water Snake. It has risen when darkness falls by the time of the March equinox.

The constellation is so long that the entire snake doesn’t rise until after midnight in March. Alphard heralds the rest of the snake, which ascends in the sky like a cobra from a snake charmer’s basket. On March, April and May evenings, this great star pattern stretches across a huge portion of the sky, from southeast to southwest above the Milky Way.

Hydra the Water Snake is the longest of the 88 constellations. It extends all the way from Cancer the Crab, below Leo the Lion, to the end of Virgo the Maiden. Image via IAU/ Wikimedia Commons (CC BY 3.0).

How to find Hydra and Alphard

Do you know the constellation Leo the Lion and its famous asterism – the Sickle – shaped like a backward question mark? If so – on an evening in March, April, or May – look for the distinctive backward question mark shape of its head and the triangle body.

You’ll find Alphard not far from Regulus, Leo’s brightest star. Alphard is not as bright as Regulus, but it’s a distinctive orange color. Both Alphard and Regulus are known as the “heart” of their respective animal constellations.

So from Northern Hemisphere locations, look southward to Leo’s lower right to find Alphard. From the Southern Hemisphere, Regulus will be following Alphard across the night sky.

If you’re in the Northern Hemisphere – and you stand facing southward on a spring evening – Leo the Lion will be over your head. Alphard will be to the lower right of Regulus, Leo’s brightest star.

The solitary one

Much like Fomalhaut six months from now, Alphard is said to be a lonely star. It beams as the sole bright light in a sea of dim stars in its part of the sky. The Arabic name Alphard translates as the Solitary One.

Look at Alphard with binoculars to discern its orange color. Alphard’s color shows that it is entering into the autumn of its years, like the color of the orange stars Pollux and Arcturus, and the ruddy star Aldebaran. Old stars’ colors are reminiscent of the orange color of autumn leaves. Like Pollux, Arcturus and Aldebaran, Alphard will shed its outer layers someday soon (by astronomical standards) and shrink into a dead white dwarf star.

Pollux, Arcturus and Aldebaran appear brighter in our sky than Alphard, but that’s because they are so much closer to us. Alphard is intrinsically brighter than any of these stars. Yet it appears fainter, because it lies some 177 light-years away, while Pollux, Arcturus and Aldebaran reside at 34, 37, and 65 light-years away, respectively.

Bottom line: Alphard is the “heart” and brightest star in the constellation Hydra, and it represents a welcome sign of spring for the Northern Hemisphere.

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The post Lonely Alphard is the brightest star in Hydra first appeared on EarthSky.

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On northern spring evenings – and southern autumn evenings – you’ll find Hydra the Water Snake ascending in the east. It is the longest constellation in the sky. And it isn’t fully up until late evenings in April for the Northern Hemisphere. Alphard – sometimes called Cor Hydrae or Hydra’s Heart – is the brightest star in Hydra. Photo copyright by Till Credner/ AlltheSky.com/ Wikimedia Commons (CC BY-SA 3.0).

Alphard (Alpha Hydrae) is the brightest star in the largest constellation in the sky, Hydra the Water Snake. Despite its long length, Hydra’s stars are mostly dim except for Alphard. You will need a very dark sky to see them. Meanwhile, Alphard shines at 2nd magnitude. So it’s about as bright as the stars of the Big Dipper.

Known as the Heart of the Snake, Alphard is a precursor of spring for us in the Northern Hemisphere.

Alphard brings a new season

Alphard’s warm orange color and location in the constellation’s core makes it a good representative for the Snake’s Heart. There is something about Alphard – some combination of its orange color and not-too-showy brightness – that looks friendly.

Like so many skywatchers before you, you’ll love seeing Alphard ascend in the early evening in late February and March as it ushers in a new season. Alphard is located in the upper part of the Water Snake. It has risen when darkness falls by the time of the March equinox.

The constellation is so long that the entire snake doesn’t rise until after midnight in March. Alphard heralds the rest of the snake, which ascends in the sky like a cobra from a snake charmer’s basket. On March, April and May evenings, this great star pattern stretches across a huge portion of the sky, from southeast to southwest above the Milky Way.

Hydra the Water Snake is the longest of the 88 constellations. It extends all the way from Cancer the Crab, below Leo the Lion, to the end of Virgo the Maiden. Image via IAU/ Wikimedia Commons (CC BY 3.0).

How to find Hydra and Alphard

Do you know the constellation Leo the Lion and its famous asterism – the Sickle – shaped like a backward question mark? If so – on an evening in March, April, or May – look for the distinctive backward question mark shape of its head and the triangle body.

You’ll find Alphard not far from Regulus, Leo’s brightest star. Alphard is not as bright as Regulus, but it’s a distinctive orange color. Both Alphard and Regulus are known as the “heart” of their respective animal constellations.

So from Northern Hemisphere locations, look southward to Leo’s lower right to find Alphard. From the Southern Hemisphere, Regulus will be following Alphard across the night sky.

If you’re in the Northern Hemisphere – and you stand facing southward on a spring evening – Leo the Lion will be over your head. Alphard will be to the lower right of Regulus, Leo’s brightest star.

The solitary one

Much like Fomalhaut six months from now, Alphard is said to be a lonely star. It beams as the sole bright light in a sea of dim stars in its part of the sky. The Arabic name Alphard translates as the Solitary One.

Look at Alphard with binoculars to discern its orange color. Alphard’s color shows that it is entering into the autumn of its years, like the color of the orange stars Pollux and Arcturus, and the ruddy star Aldebaran. Old stars’ colors are reminiscent of the orange color of autumn leaves. Like Pollux, Arcturus and Aldebaran, Alphard will shed its outer layers someday soon (by astronomical standards) and shrink into a dead white dwarf star.

Pollux, Arcturus and Aldebaran appear brighter in our sky than Alphard, but that’s because they are so much closer to us. Alphard is intrinsically brighter than any of these stars. Yet it appears fainter, because it lies some 177 light-years away, while Pollux, Arcturus and Aldebaran reside at 34, 37, and 65 light-years away, respectively.

Bottom line: Alphard is the “heart” and brightest star in the constellation Hydra, and it represents a welcome sign of spring for the Northern Hemisphere.

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The post Lonely Alphard is the brightest star in Hydra first appeared on EarthSky.

from EarthSky https://ift.tt/bComPNG