Fossils show humans’ invertebrate ancestors are older than we thought

This is an artist’s impression of Earth’s earliest complex animals during the late Ediacaran period, before the Cambrian explosion. A study of new fossils shows humans’ invertebrate ancestors arose far earlier than scientists once thought. The discovery reshapes the timeline of early animal evolution. Image via The Conversation/ Xiaodong Wang. CC BY-SA.

• Newly discovered fossils push back the origin of humans’ earliest invertebrate ancestors much further in time than scientists previously thought.
• The fossils reveal key features linking modern animals – including humans – to simple, worm-like organisms.
• The find reshapes our understanding of early animal evolution and the timeline of life on Earth.

By Luke Parry, University of Oxford; Frankie Dunn, University of Oxford, and Gaorong Li, University of Oxford

Fossils show humans’ invertebrate ancestors are much older

Animal life is extraordinarily diverse and complex, having colonized almost all environments on Earth, from hostile hydrothermal vents in the deep sea to the skies across our continents.

But the planet was not always teeming with complex animal life. For the first 3.7 billion years after it originated, life was small, simple and largely confined to the oceans. This microbe-dominated world was a tumultuous place, with several major swings in its climate.

But all this appears to have changed about 538 million years ago during the Cambrian period. This critical juncture in the history of life saw animals bursting on to the scene in an event known as the Cambrian explosion.

The appearance of animals

All sorts of animals easily recognizable as groups alive today appeared in the fossil record, from echinoderms (starfish, sea cucumbers, urchins) and arthropods (spiders, crustaceans, insects) to various types of worm. This seemingly abrupt appearance of animals in a geological blink of an eye has puzzled scientists from Charles Darwin onwards.

Many of these new lifeforms belonged to a group of animals called Bilateria, so-named for their symmetrical left and right sides. This group now contains all animals with brains and complex musculature.

However, a longstanding question for paleontologists has been whether this astonishing diversification event happened all at once during the Cambrian explosion … or if ancestors of Cambrian and modern animal groups can be traced further back in time. Our new study, published in the journal Science, could help to resolve this question.

Strange bodies

The preceding Ediacaran period (635-538 million years ago) was much more enigmatic than the Cambrian. Many organisms from that period have defied efforts to classify them. Their strange bodies – often resembling shapeless sacs or thin, quilted pillows – have no obvious counterparts among living species, let alone modern animals.

As a result, interpretations of Ediacaran creatures have encompassed almost all multicellular forms of life, from fungi and lichens to an extinct kingdom unrelated to anything multicellular alive today. These Ediacaran organisms lived in close association with mats of microbes that smothered the seafloor. They were a type of ecosystem that did not survive the advent of grazing bilaterians.

More recent evidence relating to their reproductive strategy and how they grew and developed has suggested they were, in fact, animals. Albeit they were very simple ones without any direct, living descendants.

This fossil (plus artist’s reconstruction), found in the Jiangchuan biota (~554-539 million years ago), is an early cnidarian. This is the phylum that includes jellyfish, sea anemones and corals. Scale bar: 2mm. Image via Gaorong Li and Xiaodong Wang., CC BY-SA.

Transitioning to complex animals

It isn’t until the very end of the Ediacaran period that the fossil record gives hints that more complex – and recognizable – animals were around. And most of the evidence for these bilaterian animals has come from fossilized burrows and trails. These are suggestive of complex animal life, but tell us little about the animals that made them.

This has led to much debate about the nature of the transition from the Ediacaran to the Cambrian period – the start of which geologists have defined by the action of complex animals churning up ocean sediment for the first time.

A discovery to fill the fuzzy gap

In spring 2023, one of us, Gaorong Li – then a PhD student at Yunnan Key Laboratory for Palaeobiology (YKLP) – made a discovery that helps to clarify this fuzzy gap between the weird Ediacaran world and the recognizable, complex animal-dominated Cambrian period.

Along with my PhD supervisors Wei Fan and Peiyun Cong, we explored Ediacaran rocks in the Chinese region of Eastern Yunnan. We were principally looking for fossil algae (seaweeds), the focus of my PhD thesis, in rocks known for well-preserved fossils called the Jiangchuan biota.

What we found in addition was a bizarre worm that lived tethered to the seafloor by an anchoring disc, and which could turn its strange proboscis inside out to collect food. These specimens were clearly complex animals, but not as they are known today.

We nicknamed it the bugle worm. And our team is still figuring out exactly where this strange beast fits into the classification of animals. Previously, it had been described based only on the disc anchoring it to the seafloor and named Cycliomedusa. But we found the whole organism, revealing it as something unexpected and strange.

Animals hiding in the rocks

As we continued splitting more and more rocks, it became clear there were more animals hiding in the Jiangchuan biota. In 2024 – now joined by a team from the University of Oxford including the co-authors of this article, Luke and Frankie – we went back into the field and pieced together this new fossil community.

We found some fossilized organisms characteristic of both the Ediacaran and Cambrian periods. But surprisingly, we also found some that had previously only been known from the time of the Cambrian explosion. These included a primitive animal similar to the Cambrian organism Mackenzia, as well as various worms and swimming predators called ctenophores.

Most striking of all, we found the oldest evidence for the group to which we humans belong: the deuterostomes.

A deuterostome cambroernid fossil from the Jiangchuan Biota (~554-539 million years ago), plus artist’s reconstruction (scale bar: 2mm). Image via Gaorong Li and Xiaodong Wang, CC BY-SA.

More than just the Cambrian explosion

Several of these specimens have a stalk and tentacles. They closely resemble a group of Cambrian fossils called cambroernids. These now-extinct animals are related to living starfish and acorn worms, the closest invertebrate relatives to humans. This shows our own evolutionary story has its roots in the Ediacaran period.

The discovery of diverse, complex animals in the Jingchuan biota suggests several animal groups shared the world with the weird and wonderful Ediacarans for millions of years. Diverse complex animal life has a more ancient heritage than the Cambrian explosion.

Luke Parry, Associate Professor of Palaeobiology, Department of Earth Sciences, University of Oxford; Frankie Dunn, Senior Researcher of Natural History, Museum of Natural History, University of Oxford, and Gaorong Li, China Scholarship Council Post-Doctoral Research Fellow, Museum of Natural History, University of Oxford

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

Bottom line: New fossils show humans’ invertebrate ancestors arose far earlier than thought, reshaping the timeline of early animal evolution.

Read more: Rare fossils of mass extinction survivors found in China

The post Fossils show humans’ invertebrate ancestors are older than we thought first appeared on EarthSky.

from EarthSky https://ift.tt/mUnIr8B

This is an artist’s impression of Earth’s earliest complex animals during the late Ediacaran period, before the Cambrian explosion. A study of new fossils shows humans’ invertebrate ancestors arose far earlier than scientists once thought. The discovery reshapes the timeline of early animal evolution. Image via The Conversation/ Xiaodong Wang. CC BY-SA.

• Newly discovered fossils push back the origin of humans’ earliest invertebrate ancestors much further in time than scientists previously thought.
• The fossils reveal key features linking modern animals – including humans – to simple, worm-like organisms.
• The find reshapes our understanding of early animal evolution and the timeline of life on Earth.

By Luke Parry, University of Oxford; Frankie Dunn, University of Oxford, and Gaorong Li, University of Oxford

Fossils show humans’ invertebrate ancestors are much older

Animal life is extraordinarily diverse and complex, having colonized almost all environments on Earth, from hostile hydrothermal vents in the deep sea to the skies across our continents.

But the planet was not always teeming with complex animal life. For the first 3.7 billion years after it originated, life was small, simple and largely confined to the oceans. This microbe-dominated world was a tumultuous place, with several major swings in its climate.

But all this appears to have changed about 538 million years ago during the Cambrian period. This critical juncture in the history of life saw animals bursting on to the scene in an event known as the Cambrian explosion.

The appearance of animals

All sorts of animals easily recognizable as groups alive today appeared in the fossil record, from echinoderms (starfish, sea cucumbers, urchins) and arthropods (spiders, crustaceans, insects) to various types of worm. This seemingly abrupt appearance of animals in a geological blink of an eye has puzzled scientists from Charles Darwin onwards.

Many of these new lifeforms belonged to a group of animals called Bilateria, so-named for their symmetrical left and right sides. This group now contains all animals with brains and complex musculature.

However, a longstanding question for paleontologists has been whether this astonishing diversification event happened all at once during the Cambrian explosion … or if ancestors of Cambrian and modern animal groups can be traced further back in time. Our new study, published in the journal Science, could help to resolve this question.

Strange bodies

The preceding Ediacaran period (635-538 million years ago) was much more enigmatic than the Cambrian. Many organisms from that period have defied efforts to classify them. Their strange bodies – often resembling shapeless sacs or thin, quilted pillows – have no obvious counterparts among living species, let alone modern animals.

As a result, interpretations of Ediacaran creatures have encompassed almost all multicellular forms of life, from fungi and lichens to an extinct kingdom unrelated to anything multicellular alive today. These Ediacaran organisms lived in close association with mats of microbes that smothered the seafloor. They were a type of ecosystem that did not survive the advent of grazing bilaterians.

More recent evidence relating to their reproductive strategy and how they grew and developed has suggested they were, in fact, animals. Albeit they were very simple ones without any direct, living descendants.

This fossil (plus artist’s reconstruction), found in the Jiangchuan biota (~554-539 million years ago), is an early cnidarian. This is the phylum that includes jellyfish, sea anemones and corals. Scale bar: 2mm. Image via Gaorong Li and Xiaodong Wang., CC BY-SA.

Transitioning to complex animals

It isn’t until the very end of the Ediacaran period that the fossil record gives hints that more complex – and recognizable – animals were around. And most of the evidence for these bilaterian animals has come from fossilized burrows and trails. These are suggestive of complex animal life, but tell us little about the animals that made them.

This has led to much debate about the nature of the transition from the Ediacaran to the Cambrian period – the start of which geologists have defined by the action of complex animals churning up ocean sediment for the first time.

A discovery to fill the fuzzy gap

In spring 2023, one of us, Gaorong Li – then a PhD student at Yunnan Key Laboratory for Palaeobiology (YKLP) – made a discovery that helps to clarify this fuzzy gap between the weird Ediacaran world and the recognizable, complex animal-dominated Cambrian period.

Along with my PhD supervisors Wei Fan and Peiyun Cong, we explored Ediacaran rocks in the Chinese region of Eastern Yunnan. We were principally looking for fossil algae (seaweeds), the focus of my PhD thesis, in rocks known for well-preserved fossils called the Jiangchuan biota.

What we found in addition was a bizarre worm that lived tethered to the seafloor by an anchoring disc, and which could turn its strange proboscis inside out to collect food. These specimens were clearly complex animals, but not as they are known today.

We nicknamed it the bugle worm. And our team is still figuring out exactly where this strange beast fits into the classification of animals. Previously, it had been described based only on the disc anchoring it to the seafloor and named Cycliomedusa. But we found the whole organism, revealing it as something unexpected and strange.

Animals hiding in the rocks

As we continued splitting more and more rocks, it became clear there were more animals hiding in the Jiangchuan biota. In 2024 – now joined by a team from the University of Oxford including the co-authors of this article, Luke and Frankie – we went back into the field and pieced together this new fossil community.

We found some fossilized organisms characteristic of both the Ediacaran and Cambrian periods. But surprisingly, we also found some that had previously only been known from the time of the Cambrian explosion. These included a primitive animal similar to the Cambrian organism Mackenzia, as well as various worms and swimming predators called ctenophores.

Most striking of all, we found the oldest evidence for the group to which we humans belong: the deuterostomes.

A deuterostome cambroernid fossil from the Jiangchuan Biota (~554-539 million years ago), plus artist’s reconstruction (scale bar: 2mm). Image via Gaorong Li and Xiaodong Wang, CC BY-SA.

More than just the Cambrian explosion

Several of these specimens have a stalk and tentacles. They closely resemble a group of Cambrian fossils called cambroernids. These now-extinct animals are related to living starfish and acorn worms, the closest invertebrate relatives to humans. This shows our own evolutionary story has its roots in the Ediacaran period.

The discovery of diverse, complex animals in the Jingchuan biota suggests several animal groups shared the world with the weird and wonderful Ediacarans for millions of years. Diverse complex animal life has a more ancient heritage than the Cambrian explosion.

Luke Parry, Associate Professor of Palaeobiology, Department of Earth Sciences, University of Oxford; Frankie Dunn, Senior Researcher of Natural History, Museum of Natural History, University of Oxford, and Gaorong Li, China Scholarship Council Post-Doctoral Research Fellow, Museum of Natural History, University of Oxford

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

Bottom line: New fossils show humans’ invertebrate ancestors arose far earlier than thought, reshaping the timeline of early animal evolution.

Read more: Rare fossils of mass extinction survivors found in China

The post Fossils show humans’ invertebrate ancestors are older than we thought first appeared on EarthSky.

from EarthSky https://ift.tt/mUnIr8B

Walking robots on Mars could speed up life search

View larger. | Ready for this? It’s a prototype for walking robots on Mars at the Marslabor facility at the University of Basel in Switzerland. Its builders say a robot explorer like this one could be smaller, lighter, faster and more autonomous than current rovers on Mars or the moon. Image via Tomaso Bontognali/ Frontiers.

• Robotic rovers on Mars have transformed our knowledge about the red planet. And they’ve provided tantalizing clues about possible past Martian life. But these rovers are also big, heavy and slow.
• Walking robots might be the next step. Researchers in Switzerland and the Netherlands have been testing a prototype of a walking robot that could explore the Martian surface.
• The robots move across the terrain on four legs. They’re smaller, lighter and faster than Mars rovers. They could carry arrays of science instruments. And they would also be semi-autonomous, requiring less control from humans back on Earth.

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

Walking robots on Mars and the moon

Robotic rovers have become the go-to way to explore our neighbor planet, Mars. And they’ve been super successful. But they’re also big, heavy and slow. They have to move carefully across the rocky and sandy terrain of Mars. Plus, communication delays between the rovers and Earth – and data transfer limitations – also affect their missions. Is there a better way? On March 31, 2026, researchers in Switzerland and the Netherlands announced a new idea: walking Mars robots. The research team said these robotic explorers would be semi-autonomous. This means they wouldn’t need regular assistance from humans back on Earth. And, their makers say, they could explore their surroundings – on both Mars or the moon – faster than rovers.

The researchers tested a prototype of the walking robot, named ANYmal. It could go to Mars or the moon. It could carry compact scientific instruments. And it could investigate interesting targets one-by-one and more quickly than current rovers can, according to the team.

On Mars, this would help speed up the process of searching for possible biosignatures. Biosignatures are chemical or other signs of ancient Mars life.

The researchers published the peer-reviewed details of the new exploration concept in Frontiers in Space Technologies on March 30, 2026.

Semi-autonomous legged robots equipped with compact instruments can rapidly survey planetary surfaces, accelerating resource prospecting and the search for biosignatures on the Moon and Mars.

— Science X / Phys.org (@sciencex.bsky.social) 2026-03-31T00:00:18-04:00

Field tests at Marslabor

The research team tested the robot prototype at the Marslabor facility at the University of Basel in Switzerland. The robot has four legs, reminiscent of toy dog robots. But this is no toy. It can carry a set of compact science instruments for either Martian or lunar exploration.

Marslabor simulates planetary or lunar terrain including rocks and regolith (tiny ground-up pieces of rock or dust).

And the testing was successful. Even though the science payloads on the robots are smaller than on rovers, they identified a variety of rock types and minerals. These include gypsum, carbonates, basalts, dunite and anorthosite. All of those could also be valuable resources for future astronaut missions.

View larger. | The walking robot prototype made autonomous measurements of a rock with its MICRO (microscopic imager) and Raman instruments. Right: examples of images from MICRO returned by the robot, showing the texture of 3 different lunar analogue materials in visible light, ultraviolet and infrared. Image via Gabriela Ligeza/ Frontiers.

Faster and more efficient exploration

One of the biggest advantages of using walking robots is speed. Rovers need to move fairly slowly and cautiously, especially on hazardous terrain. And the communication delays – for Mars in particular – mean that mission scientists and engineers back on Earth need to plan the rovers’ drives and other operations in advance.

The researchers compared two possible kinds of operations for the walking robots. One was traditional, with scientists providing input just as they do with rovers. The other was semi-autonomous, involving multiple science targets.

And indeed, the semi-autonomous approach was much faster. Exploratory missions typically took from 12 to 23 minutes to complete. By contrast, a rover mission took about 41 minutes to complete the same tasks. In addition, the walking robot was able to correctly identify all of its science targets. As the paper notes:

Our study demonstrates that a multi-target semi-autonomous exploration approach is a viable option for geological investigations in planetary surface missions where the inability to control a robot in real-time significantly slows down exploration times and, consequently, the scientific return of the mission.

View larger. | The Perseverance rover on Mars. Today’s rovers are incredible roving laboratories. But they are also large, heavy and slow. Image via NASA/ JPL-Caltech.

A bridge to future exploration

While this may still not be as fast as a human could perform the same tasks, it is significantly more efficient than rovers, to be sure. As such, robots like this could fill the gap between current rovers and future human explorers.

And although the science instruments would need to be more compact and less complex than those on rovers, they could still provide much useful data. The robots’ enhanced agility over rovers plays a big part in this.

The paper states:

The findings provide valuable insights for the development of semi-autonomous, high-efficiency robotic exploration systems, contributing to the advancement of future Mars missions and planetary surface exploration.

It would certainly be interesting to see robots walking on Mars instead of roving on six wheels, wouldn’t it? And maybe even someday it would be humanoid robots!

Bottom line: Researchers in Europe are testing a prototype for walking robots on Mars or the moon. Robots like this would be faster and more autonomous than current rovers.

Source: Semi-autonomous exploration of martian and lunar analogues with a legged robot using a Raman-equipped robotic arm and microscopic imager

Via Frontiers

Read more: Rubies on Mars? Rover finds fluorescent gems for 1st time

Read more: NASA testing underwater robots to explore ocean worlds

The post Walking robots on Mars could speed up life search first appeared on EarthSky.

from EarthSky https://ift.tt/3FC58pV

View larger. | Ready for this? It’s a prototype for walking robots on Mars at the Marslabor facility at the University of Basel in Switzerland. Its builders say a robot explorer like this one could be smaller, lighter, faster and more autonomous than current rovers on Mars or the moon. Image via Tomaso Bontognali/ Frontiers.

• Robotic rovers on Mars have transformed our knowledge about the red planet. And they’ve provided tantalizing clues about possible past Martian life. But these rovers are also big, heavy and slow.
• Walking robots might be the next step. Researchers in Switzerland and the Netherlands have been testing a prototype of a walking robot that could explore the Martian surface.
• The robots move across the terrain on four legs. They’re smaller, lighter and faster than Mars rovers. They could carry arrays of science instruments. And they would also be semi-autonomous, requiring less control from humans back on Earth.

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

Walking robots on Mars and the moon

Robotic rovers have become the go-to way to explore our neighbor planet, Mars. And they’ve been super successful. But they’re also big, heavy and slow. They have to move carefully across the rocky and sandy terrain of Mars. Plus, communication delays between the rovers and Earth – and data transfer limitations – also affect their missions. Is there a better way? On March 31, 2026, researchers in Switzerland and the Netherlands announced a new idea: walking Mars robots. The research team said these robotic explorers would be semi-autonomous. This means they wouldn’t need regular assistance from humans back on Earth. And, their makers say, they could explore their surroundings – on both Mars or the moon – faster than rovers.

The researchers tested a prototype of the walking robot, named ANYmal. It could go to Mars or the moon. It could carry compact scientific instruments. And it could investigate interesting targets one-by-one and more quickly than current rovers can, according to the team.

On Mars, this would help speed up the process of searching for possible biosignatures. Biosignatures are chemical or other signs of ancient Mars life.

The researchers published the peer-reviewed details of the new exploration concept in Frontiers in Space Technologies on March 30, 2026.

Semi-autonomous legged robots equipped with compact instruments can rapidly survey planetary surfaces, accelerating resource prospecting and the search for biosignatures on the Moon and Mars.

— Science X / Phys.org (@sciencex.bsky.social) 2026-03-31T00:00:18-04:00

Field tests at Marslabor

The research team tested the robot prototype at the Marslabor facility at the University of Basel in Switzerland. The robot has four legs, reminiscent of toy dog robots. But this is no toy. It can carry a set of compact science instruments for either Martian or lunar exploration.

Marslabor simulates planetary or lunar terrain including rocks and regolith (tiny ground-up pieces of rock or dust).

And the testing was successful. Even though the science payloads on the robots are smaller than on rovers, they identified a variety of rock types and minerals. These include gypsum, carbonates, basalts, dunite and anorthosite. All of those could also be valuable resources for future astronaut missions.

View larger. | The walking robot prototype made autonomous measurements of a rock with its MICRO (microscopic imager) and Raman instruments. Right: examples of images from MICRO returned by the robot, showing the texture of 3 different lunar analogue materials in visible light, ultraviolet and infrared. Image via Gabriela Ligeza/ Frontiers.

Faster and more efficient exploration

One of the biggest advantages of using walking robots is speed. Rovers need to move fairly slowly and cautiously, especially on hazardous terrain. And the communication delays – for Mars in particular – mean that mission scientists and engineers back on Earth need to plan the rovers’ drives and other operations in advance.

The researchers compared two possible kinds of operations for the walking robots. One was traditional, with scientists providing input just as they do with rovers. The other was semi-autonomous, involving multiple science targets.

And indeed, the semi-autonomous approach was much faster. Exploratory missions typically took from 12 to 23 minutes to complete. By contrast, a rover mission took about 41 minutes to complete the same tasks. In addition, the walking robot was able to correctly identify all of its science targets. As the paper notes:

Our study demonstrates that a multi-target semi-autonomous exploration approach is a viable option for geological investigations in planetary surface missions where the inability to control a robot in real-time significantly slows down exploration times and, consequently, the scientific return of the mission.

View larger. | The Perseverance rover on Mars. Today’s rovers are incredible roving laboratories. But they are also large, heavy and slow. Image via NASA/ JPL-Caltech.

A bridge to future exploration

While this may still not be as fast as a human could perform the same tasks, it is significantly more efficient than rovers, to be sure. As such, robots like this could fill the gap between current rovers and future human explorers.

And although the science instruments would need to be more compact and less complex than those on rovers, they could still provide much useful data. The robots’ enhanced agility over rovers plays a big part in this.

The paper states:

The findings provide valuable insights for the development of semi-autonomous, high-efficiency robotic exploration systems, contributing to the advancement of future Mars missions and planetary surface exploration.

It would certainly be interesting to see robots walking on Mars instead of roving on six wheels, wouldn’t it? And maybe even someday it would be humanoid robots!

Bottom line: Researchers in Europe are testing a prototype for walking robots on Mars or the moon. Robots like this would be faster and more autonomous than current rovers.

Source: Semi-autonomous exploration of martian and lunar analogues with a legged robot using a Raman-equipped robotic arm and microscopic imager

Via Frontiers

Read more: Rubies on Mars? Rover finds fluorescent gems for 1st time

Read more: NASA testing underwater robots to explore ocean worlds

The post Walking robots on Mars could speed up life search first appeared on EarthSky.

from EarthSky https://ift.tt/3FC58pV

Kochab and Pherkad: Outer bowl stars of the Little Dipper

Kochab and Pherkad are the outer stars in the bowl of the Little Dipper. Chart via EarthSky.

Meet Kochab and Pherkad

Tonight, find the stars Kochab and Pherkad in the Little Dipper.

Have you noticed it’s not easy to find the Little Dipper? That’s because it’s fainter and looks less like a dipper than the Big Dipper. The Big Dipper appears high in the northeast sky at nightfall on spring evenings and wheels above Polaris in the late evening.

So, how do you find Polaris? If you draw an imaginary line between the two outer stars in the bowl of the Big Dipper and extend that line northward on the sky’s dome, you’ll come to Polaris, the North Star. Polaris is part of the Little Dipper. It marks the end of the Little Dipper’s handle. Then, look for Kochab and Pherkad. They are the two outer stars in the bowl of the Little Dipper.

The constellation Ursa Minor. Kochab and Pherkad are the 2 outer stars in the bowl of the Little Dipper. Chart via IAU/ Sky and Telescope.

Pole stars

Of course, Polaris is special because Earth’s axis nearly points to its location in the sky. Polaris is less than a degree away from the true north celestial pole on the sky’s dome now. It’ll be closest to true north – less than half a degree away – in the year 2102. The change is due to a motion of Earth called “precession,” which causes Earth’s axis to trace out a circle among the stars every 26,000 years.

However, thousands of years ago, Polaris was an ordinary star in the northern sky, known to the Greeks by the name Phoenice.

Other ordinary stars in the northern sky – Kochab and Pherkad, the two outermost stars in the bowl of the Little Dipper (see chart above) – have had the honor of being pole stars.

Kochab and Pherkad served as twin pole stars from about 1500 BC to about 500 BC.

They’re still sometimes called the Guardians of the Pole.

Kochab is located about 130 light-years away. Pherkad is more distant, at about 487 light-years by some estimates. Meanwhile, Polaris is a about 434 light-years away.

Bottom line: Kochab and Perkad are in the Little Dipper asterism. Maybe you can find the Big Dipper but not the Little Dipper? This post will help.

EarthSky astronomy kits are perfect for beginners. Order today from the EarthSky store

The post Kochab and Pherkad: Outer bowl stars of the Little Dipper first appeared on EarthSky.

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Kochab and Pherkad are the outer stars in the bowl of the Little Dipper. Chart via EarthSky.

Meet Kochab and Pherkad

Tonight, find the stars Kochab and Pherkad in the Little Dipper.

Have you noticed it’s not easy to find the Little Dipper? That’s because it’s fainter and looks less like a dipper than the Big Dipper. The Big Dipper appears high in the northeast sky at nightfall on spring evenings and wheels above Polaris in the late evening.

So, how do you find Polaris? If you draw an imaginary line between the two outer stars in the bowl of the Big Dipper and extend that line northward on the sky’s dome, you’ll come to Polaris, the North Star. Polaris is part of the Little Dipper. It marks the end of the Little Dipper’s handle. Then, look for Kochab and Pherkad. They are the two outer stars in the bowl of the Little Dipper.

The constellation Ursa Minor. Kochab and Pherkad are the 2 outer stars in the bowl of the Little Dipper. Chart via IAU/ Sky and Telescope.

Pole stars

Of course, Polaris is special because Earth’s axis nearly points to its location in the sky. Polaris is less than a degree away from the true north celestial pole on the sky’s dome now. It’ll be closest to true north – less than half a degree away – in the year 2102. The change is due to a motion of Earth called “precession,” which causes Earth’s axis to trace out a circle among the stars every 26,000 years.

However, thousands of years ago, Polaris was an ordinary star in the northern sky, known to the Greeks by the name Phoenice.

Other ordinary stars in the northern sky – Kochab and Pherkad, the two outermost stars in the bowl of the Little Dipper (see chart above) – have had the honor of being pole stars.

Kochab and Pherkad served as twin pole stars from about 1500 BC to about 500 BC.

They’re still sometimes called the Guardians of the Pole.

Kochab is located about 130 light-years away. Pherkad is more distant, at about 487 light-years by some estimates. Meanwhile, Polaris is a about 434 light-years away.

Bottom line: Kochab and Perkad are in the Little Dipper asterism. Maybe you can find the Big Dipper but not the Little Dipper? This post will help.

EarthSky astronomy kits are perfect for beginners. Order today from the EarthSky store

The post Kochab and Pherkad: Outer bowl stars of the Little Dipper first appeared on EarthSky.

from EarthSky https://ift.tt/y7Mg0cP

Bull sharks choose companions and form lasting bonds

Bull sharks deliberately choose and maintain long-term social companions, defying the usual notion that sharks are solitary. Image via Wikipedia.

Bull sharks form specific social bonds instead of mixing randomly. That’s according to new research from more than six years at the Shark Reef Marine Reserve in Fiji. Researchers observed 184 bull sharks and discovered they actively choose companions and maintain long-term social connections. These findings challenge the common belief that sharks are solitary creatures.

The research team published its study in the peer-reviewed journal Animal Behaviour in April 2026.

Bull sharks show clear social preferences in the wild

The research showed bull sharks do not behave as solitary animals. They show distinct preferences for certain companions and deliberately choose who to associate with. Much like humans, they maintain different types of social relationships, ranging from close partners to more casual acquaintances. And, just like us, they actively avoid certain individuals. Lead author Natasha D. Marosi, an Exeter researcher and founder of Fiji Shark Lab, explained:

As humans we cultivate a range of social relationships — from casual acquaintances to our best friends — but we also actively avoid certain people — and these bull sharks are doing similar things.

Researchers from the University of Exeter, Lancaster University, Fiji Shark Lab and Beqa Adventure Divers observed the sharks over six years. They looked at broad associations and when sharks stayed close together. Plus they detailed interactions such as sharks following each other or swimming side by side. Social bonds were common among adult sharks, who also tended to associate with partners of similar size.

These images show different social interaction patterns: Lead–follow (a), parallel swim (b), lead–follow (c). Image via Animal Behaviour/ Marosi, N.D., Ellis, S., Jacoby, D.M.P., Brunnschweiler, J.M. & Croft, D.P. (CC BY-NC-ND 4.0).

Age groups and their social patterns

The study revealed clear differences in social behavior depending on life stage. Juvenile bull sharks live in rivers and estuaries. During this early stage they avoid predation, which includes avoiding adult bull sharks. Sub-adult sharks, which have not yet reached sexual maturity, usually remain in near-shore areas. Some of the braver sub-adults visit the Reserve, where they form social connections with adult sharks that may help them learn skills and integrate into the social network.

Adult sharks are highly social, frequently interacting with chosen partners. In contrast, older sharks are less socially active. Having accumulated years of experience in hunting and mating, these sharks rely less on social interactions for survival. Marosi explained:

Our results show that older sharks tend to be less social. These older individuals have many years of experience honing their skill sets, hunting and mating, and sociality may not be as integral to their survival as it is for an individual in their prime.

Benefits of social behavior

Social bonds offer multiple advantages. They help sharks learn new skills, find food and mates and avoid conflicts. Professor Darren Croft from Exeter’s Centre for Research in Animal Behaviour stated:

Contrary to commonly held perceptions of sharks, our study shows they have relatively rich and complex social lives.

Both males and females preferred female companions, but males had more social links overall. Marosi said:

Male bull sharks are physically smaller than females, thus one potential benefit they may gain is by being more socially integrated; they are buffered from aggressive confrontations with larger individuals.

A female bull shark at the Shark Reef Marine Reserve in Fiji. Video via Wikipedia.

Research and conservation relevance

Long-term observation allowed researchers to track individual sharks over many years. It also helped them understand how social patterns develop and persist. David Jacoby from Lancaster University emphasized that this approach provided valuable insights into shark behavior across different life stages:

This study capitalizes on data and knowledge from one of the longest running shark ecotourism dive sites in the world. This offered a unique opportunity to observe the detailed behavior of these individuals over many years, as they grow, develop and manage their social relationships.

Marosi added:

The Shark Reef Marine Reserve is a protected area where large numbers of sharks gather year round, giving us the ability to study individual sharks repeatedly over time.

Fiji Shark Lab is currently working alongside the Ministry of Fisheries, Fiji. By working closely with the Ministry of Fisheries, Shark Lab ensures that these insights are applied to safeguard bull shark populations effectively, helping shape conservation strategies that protect these sharks and their habitats for the long term.

Bottom line: Bull sharks form enduring social bonds, selecting preferred companions and sustaining strong, structured networks in the wild.

Source: Rolling in the deep: drivers of social preferences and social interactions within a bull shark aggregation in Fiji

Via University of Exeter

Read more: Sharks and rays leap out of the water. But why?

The post Bull sharks choose companions and form lasting bonds first appeared on EarthSky.

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Bull sharks deliberately choose and maintain long-term social companions, defying the usual notion that sharks are solitary. Image via Wikipedia.

Bull sharks form specific social bonds instead of mixing randomly. That’s according to new research from more than six years at the Shark Reef Marine Reserve in Fiji. Researchers observed 184 bull sharks and discovered they actively choose companions and maintain long-term social connections. These findings challenge the common belief that sharks are solitary creatures.

The research team published its study in the peer-reviewed journal Animal Behaviour in April 2026.

Bull sharks show clear social preferences in the wild

The research showed bull sharks do not behave as solitary animals. They show distinct preferences for certain companions and deliberately choose who to associate with. Much like humans, they maintain different types of social relationships, ranging from close partners to more casual acquaintances. And, just like us, they actively avoid certain individuals. Lead author Natasha D. Marosi, an Exeter researcher and founder of Fiji Shark Lab, explained:

As humans we cultivate a range of social relationships — from casual acquaintances to our best friends — but we also actively avoid certain people — and these bull sharks are doing similar things.

Researchers from the University of Exeter, Lancaster University, Fiji Shark Lab and Beqa Adventure Divers observed the sharks over six years. They looked at broad associations and when sharks stayed close together. Plus they detailed interactions such as sharks following each other or swimming side by side. Social bonds were common among adult sharks, who also tended to associate with partners of similar size.

These images show different social interaction patterns: Lead–follow (a), parallel swim (b), lead–follow (c). Image via Animal Behaviour/ Marosi, N.D., Ellis, S., Jacoby, D.M.P., Brunnschweiler, J.M. & Croft, D.P. (CC BY-NC-ND 4.0).

Age groups and their social patterns

The study revealed clear differences in social behavior depending on life stage. Juvenile bull sharks live in rivers and estuaries. During this early stage they avoid predation, which includes avoiding adult bull sharks. Sub-adult sharks, which have not yet reached sexual maturity, usually remain in near-shore areas. Some of the braver sub-adults visit the Reserve, where they form social connections with adult sharks that may help them learn skills and integrate into the social network.

Adult sharks are highly social, frequently interacting with chosen partners. In contrast, older sharks are less socially active. Having accumulated years of experience in hunting and mating, these sharks rely less on social interactions for survival. Marosi explained:

Our results show that older sharks tend to be less social. These older individuals have many years of experience honing their skill sets, hunting and mating, and sociality may not be as integral to their survival as it is for an individual in their prime.

Benefits of social behavior

Social bonds offer multiple advantages. They help sharks learn new skills, find food and mates and avoid conflicts. Professor Darren Croft from Exeter’s Centre for Research in Animal Behaviour stated:

Contrary to commonly held perceptions of sharks, our study shows they have relatively rich and complex social lives.

Both males and females preferred female companions, but males had more social links overall. Marosi said:

Male bull sharks are physically smaller than females, thus one potential benefit they may gain is by being more socially integrated; they are buffered from aggressive confrontations with larger individuals.

A female bull shark at the Shark Reef Marine Reserve in Fiji. Video via Wikipedia.

Research and conservation relevance

Long-term observation allowed researchers to track individual sharks over many years. It also helped them understand how social patterns develop and persist. David Jacoby from Lancaster University emphasized that this approach provided valuable insights into shark behavior across different life stages:

This study capitalizes on data and knowledge from one of the longest running shark ecotourism dive sites in the world. This offered a unique opportunity to observe the detailed behavior of these individuals over many years, as they grow, develop and manage their social relationships.

Marosi added:

The Shark Reef Marine Reserve is a protected area where large numbers of sharks gather year round, giving us the ability to study individual sharks repeatedly over time.

Fiji Shark Lab is currently working alongside the Ministry of Fisheries, Fiji. By working closely with the Ministry of Fisheries, Shark Lab ensures that these insights are applied to safeguard bull shark populations effectively, helping shape conservation strategies that protect these sharks and their habitats for the long term.

Bottom line: Bull sharks form enduring social bonds, selecting preferred companions and sustaining strong, structured networks in the wild.

Source: Rolling in the deep: drivers of social preferences and social interactions within a bull shark aggregation in Fiji

Via University of Exeter

Read more: Sharks and rays leap out of the water. But why?

The post Bull sharks choose companions and form lasting bonds first appeared on EarthSky.

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5 insights on interstellar comet 3I/ATLAS from ESA’s Juice mission

Observations of Comet 3I/ATLAS by the JANUS camera on ESA’s Juice mission. Juice caught the comet on November 5, 2025, when it was 64 million kilometers (40 million miles) away from the spacecraft. The length of the tail stretching away from the sun is about 6 million km (8 million miles) long here. Image via ESA/ Juice/ JANUS (CC BY-SA 3.0 IGO).

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

• ESA’s JUpiter ICy Moons Explorer, aka Juice, is on a mission to the largest planet in our solar system. But in November 2025, it had a chance to observe interstellar comet 3I/ATLAS.
• Juice observed Comet 3I/ATLAS releasing huge amounts of water vapor, mainly from its sun-facing side and surrounding dust coma.
• The comet’s gas and dust extend over 5 million km (3 million miles), and images show typical comet behavior, much like ordinary solar system comets.

The European Space Agency published this original story on April 2, 2026. Edits by EarthSky.

The Juice mission observes interstellar comet 3I/ATLAS

In November 2025, Juice was in the right place at the right time with the right equipment to observe interstellar comet 3I/ATLAS just after its closest approach to the sun. Our mission operations teams switched on five of Juice’s science instruments to collect information about how the active comet was behaving at the time.

Following a three-month wait to receive the data on Earth, scientists working on each of these instruments have spent the last few weeks delving into the photos, spectra and numbers. Results are still preliminary, work is still ongoing, but here are five things we’ve already learned.

1. 70 Olympic swimming pools of water vapor every day

On November 2, 2025, just four days after 3I/ATLAS had made its closest approach to the sun, Juice’s Moons And Jupiter Imaging Spectrometer (MAJIS) detected that the comet was spewing out 2,000 kg of water vapor every second. That’s equivalent to 70 Olympic swimming pools per day.

Comets – true to their ‘dirty snowball’ nickname – are mostly made of ice. As they approach the sun, this ice turns to gas and escapes the comet. The amount of water vapor leaving 3I/ATLAS is not exceptional. But it is on the high side of what we would expect from a comet close to the sun, based on what we have seen before in comets like 67P (300 kg per second) and Halley (20,000 kg per second).

These numbers depend a lot on the size of a comet and its distance from the sun. MAJIS detected 3I/ATLAS again on November 12 and 19, as it was moving away from the sun. By November 12, the amount of water vapor being released by the comet did not seem to have reduced significantly. The instrument team is planning to analyze the data from November 19 in the coming weeks.

MAJIS infrared observations of 3I/ATLAS in infrared light, overlaid on an image from Juice’s navigation camera. The instrument detected water vapor and carbon dioxide being released by the comet. Image via ESA/ Juice/ MAJIS (CC BY-SA 3.0 IGO).

2. Water vapor released in the direction of the sun

Juice’s Submillimeter Wave Instrument (SWI) also detected water vapor from 3I/ATLAS. It revealed that most of it was coming from the sun-facing side of the comet. It also appears that a lot of this water vapor is not actually coming directly from the solid part of the comet (its nucleus). Instead, it’s coming from icy dust grains that have escaped into a surrounding halo of dust and gas (its coma).

The SWI team are continuing to look into the data to determine how much ‘light’ water (normal H2O) 3I/ATLAS is releasing. It is interesting to compare this to the amount of ‘semiheavy’ water (HDO) from the comet, which has been measured by the ALMA and Webb telescopes. This ratio is a really important number in our studies of the universe. It gives a kind of ‘fingerprint’ that describes how and where an object formed.

ALMA and Webb found this ratio to be unexpectedly and extremely high for 3I/ATLAS. This may possibly be because the comet was born in a very cold and very ancient environment, where it was exposed to a lot of ultraviolet radiation from young stars. The SWI team is investigating whether the Juice data back up these findings.

3. Gas and dust stretch for 5 million km

Juice’s Ultraviolet Imaging Spectrograph (UVS) captured light coming from oxygen, hydrogen and carbon atoms in the gas and dust surrounding and trailing behind the comet. Oxygen, hydrogen, carbon and dust emit photons of light at specific wavelengths, which UVS recorded as counts per second.

UVS saw these gas elements and dust stretching up to more than 5 million km (3.1 million miles) from 3I/ATLAS’s nucleus. Gas and dust are common around active comets, with tails sometimes reaching up to 10 million km (6.2 million miles) long.

Counts of oxygen, hydrogen, carbon and dust measured by Juice’s UVS instrument from Comet 3I/ATLAS. Image via ESA (CC BY-SA 3.0 IGO).

4. This interstellar comet looks just like a normal comet!

Juice’s high-resolution science camera, JANUS (short for ‘Jovis Amorum ac Natorum Undique Scrutator’ – or ‘Scrutiniser of Jupiter, and all his loves and descendants’) also saw 3I/ATLAS spewing gas and dust.

Despite being over 60 million km (37 million miles) from 3I/ATLAS, JANUS clearly reveals the coma in which the nucleus is hiding, as well as two tails. One tail stretches away from the sun. And the other follows the path taken by the comet through the solar system. We can also see fainter shapes within the coma and tails that indicate various processes and interactions with the radiation, particles and magnetic field from the sun. The JANUS team is currently investigating these shapes in more detail.

Overall, JANUS shows that, despite its interstellar origin, Comet 3I/ATLAS was behaving like a typical comet from the solar system during a close approach to the sun.

Comet 3I/ATLAS through red and violet filters. In the red filter, the bright center of the coma is more compact and there are two tails: one straight down, and a fuzzier one going to the lower left. In the violet filter, the coma is bigger but fainter, and only one tail stands out clearly. The differences arise because different gas and dust particles release or reflect light at different wavelengths. Image via ESA (CC BY-SA 3.0 IGO).

5. 3I/ATLAS is supporting our planetary defense efforts

Juice’s Navigation Camera (NavCam) is specially designed to help Juice navigate around Jupiter’s icy moons following arrival in 2031. The encounter with 3I/ATLAS enabled us to do something totally unexpected with it.

We have already used telescopes on and around Earth to estimate the location and path of Comet 3I/ATLAS through the solar system. It seems to come from the direction of the Milky Way’s disk. Therefore, it was likely created more than 10 billion years ago.

NavCam had a much closer view of 3I/ATLAS, from a different angle as from Earth-based telescopes, during a period when the comet was not visible from Earth. This meant that ESA’s Planetary Defence team could line up NavCam images from throughout November to get a better idea of the comet’s changing position and trajectory.

In this way, the team – which usually tracks potentially hazardous asteroids – showed how powerful observations from deep-space missions can be to precisely calculate the orbits of comets or asteroids that cannot immediately be seen from Earth.

What’s more, because a comet’s trajectory is affected slightly by the release of dust and gas, the team is starting to use the trajectory measurements based on NavCam images to understand what materials – and how much of them – the comet is leaving in its wake.

Juice’s NavCam had a much closer view of 3I/ATLAS from a different angle as from Earth-based telescopes, during a period when the comet was not visible from Earth. This meant that NavCam images from throughout November 2025 could be lined up to get a better idea of the comet’s changing position and trajectory. Image via ESA/ Juice/ NavCam (CC BY-SA 3.0 IGO).

What’s next for Juice?

Instrument teams will continue to study the data, with many teams planning to publish papers on their results in the coming months. Olivier Witasse, ESA Juice Project Scientist, said:

3I/ATLAS is a rare and unexpected visitor. Its arrival came as a complete surprise. But when we realized that Juice would be close to the comet around its closest approach to the sun, we realized what a unique opportunity this was to collect a once-in-a-lifetime dataset.

Observing the comet was challenging, with no guarantee of success. But in the end, it turned into a great bonus for Juice during its journey to Jupiter.

The closest Juice came to 3I/ATLAS was about 60 million km (37 million miles), whereas it will see Jupiter’s moons from just a few hundred kilometers away. Even so, being designed and equipped to study icy moons, Juice’s instruments were a great match for the icy interstellar comet.

We still have five years to wait before Juice arrives at Jupiter in 2031. But all its instruments will be switched on once again in September 2026 when Juice returns to Earth for another gravity assist. Co-Project Scientist Claire Vallat said:

The data we are already seeing from Juice’s instruments is really promising. We are getting more excited about how well they work and how much we will reveal about Jupiter and its icy moons in the 2030s.

Bottom line: Juice reveals Comet 3I/ATLAS is highly active, with a vast gas and dust cloud. It behaves like solar system comets while offering clues to its interstellar origins.

Via ESA

The post 5 insights on interstellar comet 3I/ATLAS from ESA’s Juice mission first appeared on EarthSky.

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Observations of Comet 3I/ATLAS by the JANUS camera on ESA’s Juice mission. Juice caught the comet on November 5, 2025, when it was 64 million kilometers (40 million miles) away from the spacecraft. The length of the tail stretching away from the sun is about 6 million km (8 million miles) long here. Image via ESA/ Juice/ JANUS (CC BY-SA 3.0 IGO).

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

• ESA’s JUpiter ICy Moons Explorer, aka Juice, is on a mission to the largest planet in our solar system. But in November 2025, it had a chance to observe interstellar comet 3I/ATLAS.
• Juice observed Comet 3I/ATLAS releasing huge amounts of water vapor, mainly from its sun-facing side and surrounding dust coma.
• The comet’s gas and dust extend over 5 million km (3 million miles), and images show typical comet behavior, much like ordinary solar system comets.

The European Space Agency published this original story on April 2, 2026. Edits by EarthSky.

The Juice mission observes interstellar comet 3I/ATLAS

In November 2025, Juice was in the right place at the right time with the right equipment to observe interstellar comet 3I/ATLAS just after its closest approach to the sun. Our mission operations teams switched on five of Juice’s science instruments to collect information about how the active comet was behaving at the time.

Following a three-month wait to receive the data on Earth, scientists working on each of these instruments have spent the last few weeks delving into the photos, spectra and numbers. Results are still preliminary, work is still ongoing, but here are five things we’ve already learned.

1. 70 Olympic swimming pools of water vapor every day

On November 2, 2025, just four days after 3I/ATLAS had made its closest approach to the sun, Juice’s Moons And Jupiter Imaging Spectrometer (MAJIS) detected that the comet was spewing out 2,000 kg of water vapor every second. That’s equivalent to 70 Olympic swimming pools per day.

Comets – true to their ‘dirty snowball’ nickname – are mostly made of ice. As they approach the sun, this ice turns to gas and escapes the comet. The amount of water vapor leaving 3I/ATLAS is not exceptional. But it is on the high side of what we would expect from a comet close to the sun, based on what we have seen before in comets like 67P (300 kg per second) and Halley (20,000 kg per second).

These numbers depend a lot on the size of a comet and its distance from the sun. MAJIS detected 3I/ATLAS again on November 12 and 19, as it was moving away from the sun. By November 12, the amount of water vapor being released by the comet did not seem to have reduced significantly. The instrument team is planning to analyze the data from November 19 in the coming weeks.

MAJIS infrared observations of 3I/ATLAS in infrared light, overlaid on an image from Juice’s navigation camera. The instrument detected water vapor and carbon dioxide being released by the comet. Image via ESA/ Juice/ MAJIS (CC BY-SA 3.0 IGO).

2. Water vapor released in the direction of the sun

Juice’s Submillimeter Wave Instrument (SWI) also detected water vapor from 3I/ATLAS. It revealed that most of it was coming from the sun-facing side of the comet. It also appears that a lot of this water vapor is not actually coming directly from the solid part of the comet (its nucleus). Instead, it’s coming from icy dust grains that have escaped into a surrounding halo of dust and gas (its coma).

The SWI team are continuing to look into the data to determine how much ‘light’ water (normal H2O) 3I/ATLAS is releasing. It is interesting to compare this to the amount of ‘semiheavy’ water (HDO) from the comet, which has been measured by the ALMA and Webb telescopes. This ratio is a really important number in our studies of the universe. It gives a kind of ‘fingerprint’ that describes how and where an object formed.

ALMA and Webb found this ratio to be unexpectedly and extremely high for 3I/ATLAS. This may possibly be because the comet was born in a very cold and very ancient environment, where it was exposed to a lot of ultraviolet radiation from young stars. The SWI team is investigating whether the Juice data back up these findings.

3. Gas and dust stretch for 5 million km

Juice’s Ultraviolet Imaging Spectrograph (UVS) captured light coming from oxygen, hydrogen and carbon atoms in the gas and dust surrounding and trailing behind the comet. Oxygen, hydrogen, carbon and dust emit photons of light at specific wavelengths, which UVS recorded as counts per second.

UVS saw these gas elements and dust stretching up to more than 5 million km (3.1 million miles) from 3I/ATLAS’s nucleus. Gas and dust are common around active comets, with tails sometimes reaching up to 10 million km (6.2 million miles) long.

Counts of oxygen, hydrogen, carbon and dust measured by Juice’s UVS instrument from Comet 3I/ATLAS. Image via ESA (CC BY-SA 3.0 IGO).

4. This interstellar comet looks just like a normal comet!

Juice’s high-resolution science camera, JANUS (short for ‘Jovis Amorum ac Natorum Undique Scrutator’ – or ‘Scrutiniser of Jupiter, and all his loves and descendants’) also saw 3I/ATLAS spewing gas and dust.

Despite being over 60 million km (37 million miles) from 3I/ATLAS, JANUS clearly reveals the coma in which the nucleus is hiding, as well as two tails. One tail stretches away from the sun. And the other follows the path taken by the comet through the solar system. We can also see fainter shapes within the coma and tails that indicate various processes and interactions with the radiation, particles and magnetic field from the sun. The JANUS team is currently investigating these shapes in more detail.

Overall, JANUS shows that, despite its interstellar origin, Comet 3I/ATLAS was behaving like a typical comet from the solar system during a close approach to the sun.

Comet 3I/ATLAS through red and violet filters. In the red filter, the bright center of the coma is more compact and there are two tails: one straight down, and a fuzzier one going to the lower left. In the violet filter, the coma is bigger but fainter, and only one tail stands out clearly. The differences arise because different gas and dust particles release or reflect light at different wavelengths. Image via ESA (CC BY-SA 3.0 IGO).

5. 3I/ATLAS is supporting our planetary defense efforts

Juice’s Navigation Camera (NavCam) is specially designed to help Juice navigate around Jupiter’s icy moons following arrival in 2031. The encounter with 3I/ATLAS enabled us to do something totally unexpected with it.

We have already used telescopes on and around Earth to estimate the location and path of Comet 3I/ATLAS through the solar system. It seems to come from the direction of the Milky Way’s disk. Therefore, it was likely created more than 10 billion years ago.

NavCam had a much closer view of 3I/ATLAS, from a different angle as from Earth-based telescopes, during a period when the comet was not visible from Earth. This meant that ESA’s Planetary Defence team could line up NavCam images from throughout November to get a better idea of the comet’s changing position and trajectory.

In this way, the team – which usually tracks potentially hazardous asteroids – showed how powerful observations from deep-space missions can be to precisely calculate the orbits of comets or asteroids that cannot immediately be seen from Earth.

What’s more, because a comet’s trajectory is affected slightly by the release of dust and gas, the team is starting to use the trajectory measurements based on NavCam images to understand what materials – and how much of them – the comet is leaving in its wake.

Juice’s NavCam had a much closer view of 3I/ATLAS from a different angle as from Earth-based telescopes, during a period when the comet was not visible from Earth. This meant that NavCam images from throughout November 2025 could be lined up to get a better idea of the comet’s changing position and trajectory. Image via ESA/ Juice/ NavCam (CC BY-SA 3.0 IGO).

What’s next for Juice?

Instrument teams will continue to study the data, with many teams planning to publish papers on their results in the coming months. Olivier Witasse, ESA Juice Project Scientist, said:

3I/ATLAS is a rare and unexpected visitor. Its arrival came as a complete surprise. But when we realized that Juice would be close to the comet around its closest approach to the sun, we realized what a unique opportunity this was to collect a once-in-a-lifetime dataset.

Observing the comet was challenging, with no guarantee of success. But in the end, it turned into a great bonus for Juice during its journey to Jupiter.

The closest Juice came to 3I/ATLAS was about 60 million km (37 million miles), whereas it will see Jupiter’s moons from just a few hundred kilometers away. Even so, being designed and equipped to study icy moons, Juice’s instruments were a great match for the icy interstellar comet.

We still have five years to wait before Juice arrives at Jupiter in 2031. But all its instruments will be switched on once again in September 2026 when Juice returns to Earth for another gravity assist. Co-Project Scientist Claire Vallat said:

The data we are already seeing from Juice’s instruments is really promising. We are getting more excited about how well they work and how much we will reveal about Jupiter and its icy moons in the 2030s.

Bottom line: Juice reveals Comet 3I/ATLAS is highly active, with a vast gas and dust cloud. It behaves like solar system comets while offering clues to its interstellar origins.

Via ESA

The post 5 insights on interstellar comet 3I/ATLAS from ESA’s Juice mission first appeared on EarthSky.

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Meet the Chamaeleon, a southern constellation

The constellation Chamaeleon is a Southern Hemisphere target for April evenings. Chart via EarthSky.

The constellation of the Chamaeleon lies deep in the Southern Hemisphere sky. You have to be south of the equator to spot it. As a south circumpolar constellation, it circles closely around the south celestial pole. So, from most of the Southern Hemisphere, it never sets. And that’s why, if you’re in the Southern Hemisphere, you can see it on any night of the year.

The origin of the Chamaeleon

Pieter Dirkszoon Keyser and Frederick de Houtman created the Chamaeleon, along with 11 other Southern Hemisphere constellations, in the late 1500s. These Dutch navigators explored the Southern Hemisphere and took astronomical observations, naming the new constellations after creatures they met on their travels. The chameleon is a type of lizard, and the northern sky has its own lizard constellation: Lacerta.

Locating the constellation of the Chameleon

You can find the constellation Chamaeleon any time of year in the Southern Hemisphere between the south celestial pole and the flowing river of the Milky Way. Also, if you can find the Southern Hemisphere’s prominent constellation of the Southern Cross, or Crux, and draw a line to the south celestial pole, you’ll pass through Chamaeleon.

The dim stars of the Chamaeleon lie near the south celestial pole. Image via IAU/ Sky and Telescope/ Wikipedia. CC BY 3.0.

The stars of the Chamaeleon

The stars of the constellation are all 4th magnitude and dimmer. Alpha Chamaeleontis and Theta Chamaeleontis lie a mere 1/2 degree from each other, with Alpha at magnitude 4.06 and Theta at magnitude 4.35. They lie 63 and 155 light-years away, respectively.

Delta Chamaeleontis is a double star near the center of the constellation. Its two components, four arcminutes apart, are magnitude 4.45 and 5.46, averaging 350 light-years distant. Then two degrees away is Gamma Chamaeleontis, magnitude 4.12 and 413 light-years away. Lastly is Beta Chamaeleontis at magnitude 4.24 and 271 light-years distant, found at the opposite end of the constellation as Alpha.

The constellation is supposed to represent the type of lizard known as the chameleon. Shown here is the panther chameleon from Madagascar. Image via Wikimedia Commons.

Bottom line: The constellation Chamaeleon is a dark patch of sky that lies deep in the Southern Hemisphere and is visible any night of the year.

The post Meet the Chamaeleon, a southern constellation first appeared on EarthSky.

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The constellation Chamaeleon is a Southern Hemisphere target for April evenings. Chart via EarthSky.

The constellation of the Chamaeleon lies deep in the Southern Hemisphere sky. You have to be south of the equator to spot it. As a south circumpolar constellation, it circles closely around the south celestial pole. So, from most of the Southern Hemisphere, it never sets. And that’s why, if you’re in the Southern Hemisphere, you can see it on any night of the year.

The origin of the Chamaeleon

Pieter Dirkszoon Keyser and Frederick de Houtman created the Chamaeleon, along with 11 other Southern Hemisphere constellations, in the late 1500s. These Dutch navigators explored the Southern Hemisphere and took astronomical observations, naming the new constellations after creatures they met on their travels. The chameleon is a type of lizard, and the northern sky has its own lizard constellation: Lacerta.

Locating the constellation of the Chameleon

You can find the constellation Chamaeleon any time of year in the Southern Hemisphere between the south celestial pole and the flowing river of the Milky Way. Also, if you can find the Southern Hemisphere’s prominent constellation of the Southern Cross, or Crux, and draw a line to the south celestial pole, you’ll pass through Chamaeleon.

The dim stars of the Chamaeleon lie near the south celestial pole. Image via IAU/ Sky and Telescope/ Wikipedia. CC BY 3.0.

The stars of the Chamaeleon

The stars of the constellation are all 4th magnitude and dimmer. Alpha Chamaeleontis and Theta Chamaeleontis lie a mere 1/2 degree from each other, with Alpha at magnitude 4.06 and Theta at magnitude 4.35. They lie 63 and 155 light-years away, respectively.

Delta Chamaeleontis is a double star near the center of the constellation. Its two components, four arcminutes apart, are magnitude 4.45 and 5.46, averaging 350 light-years distant. Then two degrees away is Gamma Chamaeleontis, magnitude 4.12 and 413 light-years away. Lastly is Beta Chamaeleontis at magnitude 4.24 and 271 light-years distant, found at the opposite end of the constellation as Alpha.

The constellation is supposed to represent the type of lizard known as the chameleon. Shown here is the panther chameleon from Madagascar. Image via Wikimedia Commons.

Bottom line: The constellation Chamaeleon is a dark patch of sky that lies deep in the Southern Hemisphere and is visible any night of the year.

The post Meet the Chamaeleon, a southern constellation first appeared on EarthSky.

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See the best deep-sky photos of March 2026

View at EarthSky Community Photos. | Catherine Hyde in Cambria, California, captured this telescopic view of Messier 53 on March 24, 2026. Catherine wrote: “This is the globular cluster M53 in Coma Berenices.” Thank you, Catherine! See more deep-sky photos from March 2026 below.

Stunning deep-sky photos from our community

The EarthSky community has many talented astrophotographers who capture stunning images of the deep sky. We gathered some of our favorite deep-sky photos we received in March 2026 for you to enjoy. Do you have images of your own to share? You can submit them to us here. We would love to see them!

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Deep-sky photos of diffuse nebulae

View at EarthSky Community Photos. | Jelieta Walinski at Desert Bloom Observatory in St. David, Arizona, used more than 100 hours of exposures to image this emerald nebula. Jelieta wrote: “In a quiet region of the constellation Serpens, this emission nebula reveals itself as a cosmic bloom. This deep image transforms faint hydrogen gas into a luminous structure resembling a flower unfolding in green radiance.” Thank you, Jelieta!

View at EarthSky Community Photos. | Mohammed Ahmed in Suez, Egypt, used a telephoto lens to capture this view of the Horsehead Nebula in the constellation Orion on March 22, 2026. Mohammed wrote: “I wanted to say goodbye to winter with this shot. This is the famous Horsehead Nebula, a dark nebula located in Orion near the star Alnitak. It’s one of the hidden gems of the winter sky, and now we will have to wait for next winter for Orion to come back.” Thank you, Mohammed!

View at EarthSky Community Photos. | Kueng Cornelia in Lake Zurich, Switzerland, captured this telescopic view of the Seagull Nebula, in the constellation Monoceros, on March 18, 2025. Kueng wrote: “I am on the way to collect nebulae with animal names for my lovely grandchildren. Just now in my backyard toward the south, IC 2177 – the Seagull Nebula – is in good position.” Thank you, Kueng!

More diffuse nebulae

View at EarthSky Community Photos. | Catherine Hyde in Cambria, California, captured this telescopic view of the Medusa Nebula on March 24, 2026. Catherine wrote: “This is the Medusa Nebula, a very old planetary nebula in the constellation Gemini. This is a stacked image using about 16 hours of total exposure time over 4 nights.” Thank you, Catherine!

View at EarthSky Community Photos. | Mohammed Ahmed in Suez, Egypt, used a telephoto lens to capture this view of Thor’s Helmet in the constellation Canis Major, on March 12, 2026. Mohammed wrote: “This is Thor’s Helmet Nebula (NGC 2359). What you’re seeing here is the interstellar wind and a pre-supernova of a Wolf-Rayet star. This is a dying star, and we are seeing it about 12,000 light-years away.” Thank you, Mohammed!

Deep-sky photos of distant galaxies

View at EarthSky Community Photos. | Steven Bellavia in Smithfield, Virginia, captured this telescopic view of Messier 82, the Starburst Galaxy in Ursa Major, on March 10, 2026. Steven wrote: “M82 had a gravitational interaction with its larger neighbor, galaxy M81. This, in turn, funneled large amounts of gas toward the core of M82, which then triggered intense star formation at a rate 10 times faster than in our Milky Way.” Thank you, Steven!

View at EarthSky Community Photos. | Steven Bellavia in Scottsburg, Virginia, captured these exposures of the Leo Triplet of Galaxies on March 19, 2026. Steven wrote: “I have always enjoyed images of the Leo Triplet of galaxies. But I have also always wanted to capture them close up, one at a time, as each one is beautiful and full of intricate colors and details, often missed in the wide-field images. So on my recent astro-camping trip to the Staunton River Star Party, I captured 2 of the 3, close up, with the 3rd from a year ago, also from the same star party.” Thank you, Steven!

Bottom line: Without a doubt, you’ll enjoy this gallery of deep-sky photos for March 2026 from our EarthSky community. If you have a great photo to share, send it in, too. We love to see them!

Share your recent Earth or sky photo at EarthSky Community Photos.

Read more: Messier objects are fuzzy patches in the night sky

The post See the best deep-sky photos of March 2026 first appeared on EarthSky.

from EarthSky https://ift.tt/VsKZ2Xt

View at EarthSky Community Photos. | Catherine Hyde in Cambria, California, captured this telescopic view of Messier 53 on March 24, 2026. Catherine wrote: “This is the globular cluster M53 in Coma Berenices.” Thank you, Catherine! See more deep-sky photos from March 2026 below.

Stunning deep-sky photos from our community

The EarthSky community has many talented astrophotographers who capture stunning images of the deep sky. We gathered some of our favorite deep-sky photos we received in March 2026 for you to enjoy. Do you have images of your own to share? You can submit them to us here. We would love to see them!

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.

Deep-sky photos of diffuse nebulae

View at EarthSky Community Photos. | Jelieta Walinski at Desert Bloom Observatory in St. David, Arizona, used more than 100 hours of exposures to image this emerald nebula. Jelieta wrote: “In a quiet region of the constellation Serpens, this emission nebula reveals itself as a cosmic bloom. This deep image transforms faint hydrogen gas into a luminous structure resembling a flower unfolding in green radiance.” Thank you, Jelieta!

View at EarthSky Community Photos. | Mohammed Ahmed in Suez, Egypt, used a telephoto lens to capture this view of the Horsehead Nebula in the constellation Orion on March 22, 2026. Mohammed wrote: “I wanted to say goodbye to winter with this shot. This is the famous Horsehead Nebula, a dark nebula located in Orion near the star Alnitak. It’s one of the hidden gems of the winter sky, and now we will have to wait for next winter for Orion to come back.” Thank you, Mohammed!

View at EarthSky Community Photos. | Kueng Cornelia in Lake Zurich, Switzerland, captured this telescopic view of the Seagull Nebula, in the constellation Monoceros, on March 18, 2025. Kueng wrote: “I am on the way to collect nebulae with animal names for my lovely grandchildren. Just now in my backyard toward the south, IC 2177 – the Seagull Nebula – is in good position.” Thank you, Kueng!

More diffuse nebulae

View at EarthSky Community Photos. | Catherine Hyde in Cambria, California, captured this telescopic view of the Medusa Nebula on March 24, 2026. Catherine wrote: “This is the Medusa Nebula, a very old planetary nebula in the constellation Gemini. This is a stacked image using about 16 hours of total exposure time over 4 nights.” Thank you, Catherine!

View at EarthSky Community Photos. | Mohammed Ahmed in Suez, Egypt, used a telephoto lens to capture this view of Thor’s Helmet in the constellation Canis Major, on March 12, 2026. Mohammed wrote: “This is Thor’s Helmet Nebula (NGC 2359). What you’re seeing here is the interstellar wind and a pre-supernova of a Wolf-Rayet star. This is a dying star, and we are seeing it about 12,000 light-years away.” Thank you, Mohammed!

Deep-sky photos of distant galaxies

View at EarthSky Community Photos. | Steven Bellavia in Smithfield, Virginia, captured this telescopic view of Messier 82, the Starburst Galaxy in Ursa Major, on March 10, 2026. Steven wrote: “M82 had a gravitational interaction with its larger neighbor, galaxy M81. This, in turn, funneled large amounts of gas toward the core of M82, which then triggered intense star formation at a rate 10 times faster than in our Milky Way.” Thank you, Steven!

View at EarthSky Community Photos. | Steven Bellavia in Scottsburg, Virginia, captured these exposures of the Leo Triplet of Galaxies on March 19, 2026. Steven wrote: “I have always enjoyed images of the Leo Triplet of galaxies. But I have also always wanted to capture them close up, one at a time, as each one is beautiful and full of intricate colors and details, often missed in the wide-field images. So on my recent astro-camping trip to the Staunton River Star Party, I captured 2 of the 3, close up, with the 3rd from a year ago, also from the same star party.” Thank you, Steven!

Bottom line: Without a doubt, you’ll enjoy this gallery of deep-sky photos for March 2026 from our EarthSky community. If you have a great photo to share, send it in, too. We love to see them!

Share your recent Earth or sky photo at EarthSky Community Photos.

Read more: Messier objects are fuzzy patches in the night sky

The post See the best deep-sky photos of March 2026 first appeared on EarthSky.

from EarthSky https://ift.tt/VsKZ2Xt