NASA says organics on Mars are hard to explain without life

View original. | The Mars Curiosity rover captured this image of the drill hole in the Cumberland mudstone that it first investigated back in 2013. A new study from NASA suggests the long-chain organic molecules it found in the rock – thought to have likely come from fatty acids and/or alkanes – can’t be explained by non-biological processes alone. Are these organics on Mars evidence of past life? Image via NASA/ JPL-Caltech/ MSSS.

• NASA’s Curiosity rover found complex organic molecules on Mars. Scientists think they are the remains of fatty acids. Could ancient life have produced them?
• The organics were surprisingly abundant in the mudstone before radiation began to destroy them, a new NASA-led study shows.
• Non-biological sources don’t fully explain the abundance and complexity of the organics, the study says. But more work is needed to understand their origin.

EarthSky’s 2026 lunar calendar is available now. Get yours today! Makes a great gift.

Complex organics on Mars: A sign of life?

Almost a year ago, NASA’s Curiosity rover found something quite intriguing: long-chain organic molecules that scientists said could have come from fatty acids and/or alkanes. Fatty acids are common in life on Earth. Could they be evidence for ancient martian life? That possibility just got another boost from an international team of researchers led by NASA’s Goddard Space Flight Center in Maryland. The researchers said on February 6, 2026, that additional studies of the data from Curiosity show that non-biological sources they had considered don’t fully explain the organics. They conclude, therefore, that a biological source is a reasonable hypothesis.

The paper proposes two possible explanations: hydrothermal synthesis of the molecules or an ancient biosphere of microorganisms.

Curiosity found the complex organics – long-chain fatty acids and/or alkanes – in mudstone rocks in Gale Crater. Curiosity has been exploring this crater since 2012. The crater used to hold a lake or series of lakes billions of years ago.

This still isn’t proof of past life on Mars. But it certainly adds to the growing hints that Mars might have once been home to microbial life (and still could be).

The researchers published their peer-reviewed findings in a new hypothesis paper in the journal Astrobiology on February 4, 2026.

NASA Study: Non-biologic Processes Don't Fully Explain Mars Organicsastrobiology.com/2026/02/nasa… #astrobiology #Mars

— Astrobiology (@astrobiology.bsky.social) 2026-02-09T19:42:34.417Z

Organics in Gale Crater

NASA first reported the tantalizing finding back in March 2025. The rover found small amounts of the long-chain organic molecules decane, undecane and dodecane in the mudstone samples it analyzed. The samples came from a fine-grained sedimentary mudstone rock nicknamed Cumberland. They were the largest organics that any Mars mission had discovered so far. The rover’s onboard lab analysis suggested they were likely the remains of fatty acids and/or alkanes.

That’s significant, because on Earth, fatty acids are mostly produced by living organisms. Geological process can create them too, though.

NASA’s Curiosity rover found the largest organic molecules on Mars yet. Did ancient life produce them? Video via NASA Goddard.

Rewinding the clock

The researchers wanted to know how much organic material was present in the rock before radiation from the sun destroyed it while hitting the surface. That would provide clues as to whether it was small amounts from sources such as meteorites or dust or larger amounts that would be more difficult to explain without biology.

The researchers used a combination of lab radiation experiments, mathematical modeling and data from Curiosity itself. This allowed them to “rewind the clock” about 80 million years. That’s how long the rock would have been exposed on the martian surface.

View larger. | Graphic depicting the long-chain organic molecules decane, undecane and dodecane. Image via NASA/ Dan Gallagher.

An abundance of organics on Mars

Intriguingly, the results showed the rock had an abundance of the organic molecules before radiation began to destroy them. That is difficult to explain without biology. The press release said:

As the non-biological sources they considered could not fully explain the abundance of organic compounds, it is therefore reasonable to hypothesize that living things could have formed them.

As the paper explains:

The measured abundance of long-chain alkanes and their possible carboxylic acid precursors found in the ancient Cumberland mudstone in Gale Crater would have been substantially higher before the onset of exposure to ionizing radiation approximately 80 million years ago. Based on recent radiolysis experiments, we estimate conservatively that the Cumberland mudstone would have contained 120–7700 ppm of long-chain alkanes and/or fatty acids before ionizing radiation exposure. Such a high concentration of large organic molecules in martian sedimentary rocks cannot be readily explained by the accretion of organics from carbon-rich interplanetary dust particles and meteorites, nor by the deposition of hypothetical haze-derived organics from an ancient martian atmosphere.

Hydrothermal activity or biology?

The study focuses on two primary possibilities. One is that the organics were formed by hydrothermal activity. However, analysis of the mudstone rock itself showed it had not experienced the high temperatures associated with hydrothermal activity. The researchers also considered serpentinization, a low-temperature metamorphic and hydration process where water reacts with ultramafic, olivine- and pyroxene-rich rocks from the Earth’s mantle, transforming them into serpentinite. But the rover didn’t find any telltale serpentine minerals in the rock. Also, if either of those two processes formed the organics, it must have occurred elsewhere, with water later transporting the organics to the Cumberland location.

It would also imply that there were abundant organics in the surrounding early Noachian (early Mars) rocks of Gale Crater. But only trace amounts have ever been detected so far.

The other, more exciting, possibility is that the organics, such as the former fatty acids, were the products of life, just as most of them on Earth are. The long-chain molecules are suggestive of an ancient martian biosphere of microorganisms. It is hard to assess that, however, because the parameters of the experiments with the Sample Analysis at Mars (SAM) instrument on Curiosity made it difficult to detect both shorter and even longer-chain molecules. Scientists would need to compare them to the known long-chain molecules to more accurately assess their abundance.

View larger. | This Mastcam image from Curiosity shows the drilling target at the Cumberland mudstone on May 15, 2013. Image via NASA/ JPL-Caltech.

More study needed

A lot more study is required to further determine whether these organics really could be evidence of past life. For now, the paper concludes:

We agree with Carl Sagan’s claim that extraordinary claims require extraordinary evidence and understand that any purported detection of life on Mars will necessarily be met with intense scrutiny. In addition, in practice with established norms in the field of astrobiology, we note that the certainty of a life detection beyond Earth will require multiple lines of evidence. Nevertheless, our approach has led us to estimate that the Cumberland mudstone conservatively contained 120–7700 ppm of long-chain alkanes and/or fatty acids before exposure to ionizing radiation. We argue that such high concentrations of long-chain alkanes are inconsistent with a few known abiotic sources of organic molecules on ancient Mars.

To improve the ability to predict the types and concentrations of organic molecules that could have been preserved in ancient sedimentary rocks exposed to ionizing radiation at the martian surface – regardless of their origin – we recommend experimental studies that determine the radiolytic degradation rates of kerogens, alkanes and fatty acids in Cumberland-like Mars analogs under Mars-like conditions.

Bottom line: NASA’s Curiosity rover found complex organics on Mars, possibly remains of fatty acids. A new NASA study suggests they are difficult to explain without life.

Source: Does the Measured Abundance Suggest a Biological Origin for the Ancient Alkanes Preserved in a Martian Mudstone?

Via NASA

Read more: Surprisingly big organic molecules on Mars: A hint of life?

Read more: Life on Mars? Odd rings and spots tantalize scientists

The post NASA says organics on Mars are hard to explain without life first appeared on EarthSky.

from EarthSky https://ift.tt/uUNYr1R

View original. | The Mars Curiosity rover captured this image of the drill hole in the Cumberland mudstone that it first investigated back in 2013. A new study from NASA suggests the long-chain organic molecules it found in the rock – thought to have likely come from fatty acids and/or alkanes – can’t be explained by non-biological processes alone. Are these organics on Mars evidence of past life? Image via NASA/ JPL-Caltech/ MSSS.

• NASA’s Curiosity rover found complex organic molecules on Mars. Scientists think they are the remains of fatty acids. Could ancient life have produced them?
• The organics were surprisingly abundant in the mudstone before radiation began to destroy them, a new NASA-led study shows.
• Non-biological sources don’t fully explain the abundance and complexity of the organics, the study says. But more work is needed to understand their origin.

EarthSky’s 2026 lunar calendar is available now. Get yours today! Makes a great gift.

Complex organics on Mars: A sign of life?

Almost a year ago, NASA’s Curiosity rover found something quite intriguing: long-chain organic molecules that scientists said could have come from fatty acids and/or alkanes. Fatty acids are common in life on Earth. Could they be evidence for ancient martian life? That possibility just got another boost from an international team of researchers led by NASA’s Goddard Space Flight Center in Maryland. The researchers said on February 6, 2026, that additional studies of the data from Curiosity show that non-biological sources they had considered don’t fully explain the organics. They conclude, therefore, that a biological source is a reasonable hypothesis.

The paper proposes two possible explanations: hydrothermal synthesis of the molecules or an ancient biosphere of microorganisms.

Curiosity found the complex organics – long-chain fatty acids and/or alkanes – in mudstone rocks in Gale Crater. Curiosity has been exploring this crater since 2012. The crater used to hold a lake or series of lakes billions of years ago.

This still isn’t proof of past life on Mars. But it certainly adds to the growing hints that Mars might have once been home to microbial life (and still could be).

The researchers published their peer-reviewed findings in a new hypothesis paper in the journal Astrobiology on February 4, 2026.

NASA Study: Non-biologic Processes Don't Fully Explain Mars Organicsastrobiology.com/2026/02/nasa… #astrobiology #Mars

— Astrobiology (@astrobiology.bsky.social) 2026-02-09T19:42:34.417Z

Organics in Gale Crater

NASA first reported the tantalizing finding back in March 2025. The rover found small amounts of the long-chain organic molecules decane, undecane and dodecane in the mudstone samples it analyzed. The samples came from a fine-grained sedimentary mudstone rock nicknamed Cumberland. They were the largest organics that any Mars mission had discovered so far. The rover’s onboard lab analysis suggested they were likely the remains of fatty acids and/or alkanes.

That’s significant, because on Earth, fatty acids are mostly produced by living organisms. Geological process can create them too, though.

NASA’s Curiosity rover found the largest organic molecules on Mars yet. Did ancient life produce them? Video via NASA Goddard.

Rewinding the clock

The researchers wanted to know how much organic material was present in the rock before radiation from the sun destroyed it while hitting the surface. That would provide clues as to whether it was small amounts from sources such as meteorites or dust or larger amounts that would be more difficult to explain without biology.

The researchers used a combination of lab radiation experiments, mathematical modeling and data from Curiosity itself. This allowed them to “rewind the clock” about 80 million years. That’s how long the rock would have been exposed on the martian surface.

View larger. | Graphic depicting the long-chain organic molecules decane, undecane and dodecane. Image via NASA/ Dan Gallagher.

An abundance of organics on Mars

Intriguingly, the results showed the rock had an abundance of the organic molecules before radiation began to destroy them. That is difficult to explain without biology. The press release said:

As the non-biological sources they considered could not fully explain the abundance of organic compounds, it is therefore reasonable to hypothesize that living things could have formed them.

As the paper explains:

The measured abundance of long-chain alkanes and their possible carboxylic acid precursors found in the ancient Cumberland mudstone in Gale Crater would have been substantially higher before the onset of exposure to ionizing radiation approximately 80 million years ago. Based on recent radiolysis experiments, we estimate conservatively that the Cumberland mudstone would have contained 120–7700 ppm of long-chain alkanes and/or fatty acids before ionizing radiation exposure. Such a high concentration of large organic molecules in martian sedimentary rocks cannot be readily explained by the accretion of organics from carbon-rich interplanetary dust particles and meteorites, nor by the deposition of hypothetical haze-derived organics from an ancient martian atmosphere.

Hydrothermal activity or biology?

The study focuses on two primary possibilities. One is that the organics were formed by hydrothermal activity. However, analysis of the mudstone rock itself showed it had not experienced the high temperatures associated with hydrothermal activity. The researchers also considered serpentinization, a low-temperature metamorphic and hydration process where water reacts with ultramafic, olivine- and pyroxene-rich rocks from the Earth’s mantle, transforming them into serpentinite. But the rover didn’t find any telltale serpentine minerals in the rock. Also, if either of those two processes formed the organics, it must have occurred elsewhere, with water later transporting the organics to the Cumberland location.

It would also imply that there were abundant organics in the surrounding early Noachian (early Mars) rocks of Gale Crater. But only trace amounts have ever been detected so far.

The other, more exciting, possibility is that the organics, such as the former fatty acids, were the products of life, just as most of them on Earth are. The long-chain molecules are suggestive of an ancient martian biosphere of microorganisms. It is hard to assess that, however, because the parameters of the experiments with the Sample Analysis at Mars (SAM) instrument on Curiosity made it difficult to detect both shorter and even longer-chain molecules. Scientists would need to compare them to the known long-chain molecules to more accurately assess their abundance.

View larger. | This Mastcam image from Curiosity shows the drilling target at the Cumberland mudstone on May 15, 2013. Image via NASA/ JPL-Caltech.

More study needed

A lot more study is required to further determine whether these organics really could be evidence of past life. For now, the paper concludes:

We agree with Carl Sagan’s claim that extraordinary claims require extraordinary evidence and understand that any purported detection of life on Mars will necessarily be met with intense scrutiny. In addition, in practice with established norms in the field of astrobiology, we note that the certainty of a life detection beyond Earth will require multiple lines of evidence. Nevertheless, our approach has led us to estimate that the Cumberland mudstone conservatively contained 120–7700 ppm of long-chain alkanes and/or fatty acids before exposure to ionizing radiation. We argue that such high concentrations of long-chain alkanes are inconsistent with a few known abiotic sources of organic molecules on ancient Mars.

To improve the ability to predict the types and concentrations of organic molecules that could have been preserved in ancient sedimentary rocks exposed to ionizing radiation at the martian surface – regardless of their origin – we recommend experimental studies that determine the radiolytic degradation rates of kerogens, alkanes and fatty acids in Cumberland-like Mars analogs under Mars-like conditions.

Bottom line: NASA’s Curiosity rover found complex organics on Mars, possibly remains of fatty acids. A new NASA study suggests they are difficult to explain without life.

Source: Does the Measured Abundance Suggest a Biological Origin for the Ancient Alkanes Preserved in a Martian Mudstone?

Via NASA

Read more: Surprisingly big organic molecules on Mars: A hint of life?

Read more: Life on Mars? Odd rings and spots tantalize scientists

The post NASA says organics on Mars are hard to explain without life first appeared on EarthSky.

from EarthSky https://ift.tt/uUNYr1R

Can you see Canopus, the 2nd-brightest star?

Sirius is the sky’s brightest star. You’ll always know it’s Sirius because Orion’s Belt – 3 stars in a short, straight row – points to it. As seen from latitudes like those in Florida, Texas or southern California, Canopus – the 2nd brightest star – arcs across the south below Sirius on February evenings. From farther south, Sirius and Canopus cross higher in the sky, like almost-twin diamonds.

Can you see Canopus?

If you stay at latitudes like those in the northern U.S., you’ll never see Canopus. That’s why this star has become a holy grail of sorts for some Northern Hemisphere skywatchers, who take winter vacations at southerly latitudes (like those in the southern U.S.), just to catch a glimpse of it. From latitudes like those in the southern U.S., Canopus – the sky’s 2nd-brightest star – appears as a bright light closer to the horizon than Sirius (the sky’s brightest star). For those southerly observers, Canopus and Sirius arc across the south together on February evenings.

Will you see Canopus? It depends, basically, on how far south you are, and what time of year you’re looking. Canopus never rises above the horizon for locations north of about 37 degrees north latitude. In the United States, that line runs from roughly Richmond, Virginia; westward to Bowling Green, Kentucky; through Trinidad, Colorado and onward to San Jose, California. Here’s a list of global locations at the 37th parallel north. You must be south of that line to see Canopus.

February evenings are ideal

Right now, February evenings are a perfect time to look for Canopus. Then, this star is at its highest in the sky around 9 p.m. your local time (the time on your clock no matter where you are on the globe). From the Northern Hemisphere, Canopus appears in the southern sky almost directly south of Sirius. When Sirius is at its highest point to the south, Canopus is about 36 degrees below it.

For observers in the Southern Hemisphere, it’s an entirely different story. From latitudes south of the equator, both Canopus and Sirius appear higher in the sky. Indeed, they are like twin beacons crossing overhead together.

For sure, the sight of them is enough to make a northern observer envy the southern skies!

Science of Canopus

According to data obtained by the Hipparcos Space Astrometry Mission, Canopus is about 310 light-years away.

Spectroscopically, it is an F0 type star, making it significantly hotter than our sun (roughly 13,600 degrees Fahrenheit or 7,500 degrees Celsius) at its surface. This is compared to about 10,000 degrees F or 5,500 degrees C for the sun.

Canopus also has a luminosity class rating of II, which makes it a “bright giant” star much larger than the sun. (Some classifications make it a type Ia “supergiant.”)

If the sun and Canopus were side by side, it would take about 71 suns, altogether, to fit across Canopus. Canopus appears significantly less bright than Sirius, but it is much brighter, blazing with the brilliance of 10,000 suns!

Although its exact age is unknown, Canopus’ great mass dictates that this star must be near the end of its lifetime. It is likely a few million to a few tens of millions of years old. Compared to our sedate middle-aged 5-billion-year-old sun, Canopus has lived in the stellar fast lane and is destined to die young.

Canopus in science fiction

In Frank Herbert‘s 1965 novel Dune and other novels in his Dune universe, the fictional planet Arrakis is a vast desert world. It is home to sandworms and Bedouin-like humans called the Fremen. It is the third planet from a real star in our night sky. That star is Canopus.

In Herbert’s novel, the desert planet Arrakis is the only source of “spice,” the most important and valuable substance in the Dune universe. This “spice” is what makes star travel possible, in this fictional universe.

It’s possible, according to Wikipedia (which references the famous book Star Names: Their Lore and Meaning by Richard Hinckley Allen), that Herbert was influenced in his choice of this star as the primary for Arrakis by a common etymological derivation of the name Canopus:

… as a Latinization (through Greek Kanobos) from the Coptic Kahi Nub (“Golden Earth”), which refers to how Canopus would have appeared over the southern desert horizon in ancient Egypt, reddened by atmospheric absorption.

And it’s true … from much of the classical world in ancient times, Canopus would have appeared low in the sky, when it was visible at all. And so, yes, its bright light would be reddened due to looking at it through a greater thickness of atmosphere in the direction toward the horizon. Just as, for example, our sun or moon seen low in the sky looks redder than usual. Golden Earth indeed.

By the way, although Arrakis is fictional, Canopus is not only very real but also much hotter and larger than our sun.

History and mythology

Canopus is also called Alpha Carinae, the brightest star in the constellation Carina the Keel. This constellation used to be considered part of Argo Navis, the ship of Jason and his famed Argonauts, as seen in our sky. Canopus originally marked a keel or rudder of this ancient celestial ship. Alas, the great Argo Navis constellation no longer exists. Modern imaginations see it as broken into three parts: the Keel (Carina, of which Canopus is part), sails (Vela) and the poop deck (Puppis).

For those far enough south to see it, Canopus was a star of great importance from ancient times to modern times as a primary navigational star. This is, surely, due to its brightness.

The origin of the name Canopus is subject to question. By some accounts it is the name of a ship’s captain from the Trojan War. Another theory is that it is from ancient Egyptian meaning Golden Earth. It’s a possible reference to the star’s appearance as seen through atmospheric haze near the horizon from Egyptian latitudes.

The position of Canopus is RA: 6h 23m 57s, Dec: -52° 41′ 45″

Drawing from Urania’s Mirror, 1824. Carina is part of the ancient ship Argo Navis in the lower right corner. Image via Sidney Hall/ Wikipedia (public domain).

Bottom line: Canopus is the 2nd-brightest star as seen from Earth. To see Canopus, you must either be in the Southern Hemisphere or below the Northern Hemisphere’s 37th parallel north.

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The post Can you see Canopus, the 2nd-brightest star? first appeared on EarthSky.

from EarthSky https://ift.tt/pLhfinl

Sirius is the sky’s brightest star. You’ll always know it’s Sirius because Orion’s Belt – 3 stars in a short, straight row – points to it. As seen from latitudes like those in Florida, Texas or southern California, Canopus – the 2nd brightest star – arcs across the south below Sirius on February evenings. From farther south, Sirius and Canopus cross higher in the sky, like almost-twin diamonds.

Can you see Canopus?

If you stay at latitudes like those in the northern U.S., you’ll never see Canopus. That’s why this star has become a holy grail of sorts for some Northern Hemisphere skywatchers, who take winter vacations at southerly latitudes (like those in the southern U.S.), just to catch a glimpse of it. From latitudes like those in the southern U.S., Canopus – the sky’s 2nd-brightest star – appears as a bright light closer to the horizon than Sirius (the sky’s brightest star). For those southerly observers, Canopus and Sirius arc across the south together on February evenings.

Will you see Canopus? It depends, basically, on how far south you are, and what time of year you’re looking. Canopus never rises above the horizon for locations north of about 37 degrees north latitude. In the United States, that line runs from roughly Richmond, Virginia; westward to Bowling Green, Kentucky; through Trinidad, Colorado and onward to San Jose, California. Here’s a list of global locations at the 37th parallel north. You must be south of that line to see Canopus.

February evenings are ideal

Right now, February evenings are a perfect time to look for Canopus. Then, this star is at its highest in the sky around 9 p.m. your local time (the time on your clock no matter where you are on the globe). From the Northern Hemisphere, Canopus appears in the southern sky almost directly south of Sirius. When Sirius is at its highest point to the south, Canopus is about 36 degrees below it.

For observers in the Southern Hemisphere, it’s an entirely different story. From latitudes south of the equator, both Canopus and Sirius appear higher in the sky. Indeed, they are like twin beacons crossing overhead together.

For sure, the sight of them is enough to make a northern observer envy the southern skies!

Science of Canopus

According to data obtained by the Hipparcos Space Astrometry Mission, Canopus is about 310 light-years away.

Spectroscopically, it is an F0 type star, making it significantly hotter than our sun (roughly 13,600 degrees Fahrenheit or 7,500 degrees Celsius) at its surface. This is compared to about 10,000 degrees F or 5,500 degrees C for the sun.

Canopus also has a luminosity class rating of II, which makes it a “bright giant” star much larger than the sun. (Some classifications make it a type Ia “supergiant.”)

If the sun and Canopus were side by side, it would take about 71 suns, altogether, to fit across Canopus. Canopus appears significantly less bright than Sirius, but it is much brighter, blazing with the brilliance of 10,000 suns!

Although its exact age is unknown, Canopus’ great mass dictates that this star must be near the end of its lifetime. It is likely a few million to a few tens of millions of years old. Compared to our sedate middle-aged 5-billion-year-old sun, Canopus has lived in the stellar fast lane and is destined to die young.

Canopus in science fiction

In Frank Herbert‘s 1965 novel Dune and other novels in his Dune universe, the fictional planet Arrakis is a vast desert world. It is home to sandworms and Bedouin-like humans called the Fremen. It is the third planet from a real star in our night sky. That star is Canopus.

In Herbert’s novel, the desert planet Arrakis is the only source of “spice,” the most important and valuable substance in the Dune universe. This “spice” is what makes star travel possible, in this fictional universe.

It’s possible, according to Wikipedia (which references the famous book Star Names: Their Lore and Meaning by Richard Hinckley Allen), that Herbert was influenced in his choice of this star as the primary for Arrakis by a common etymological derivation of the name Canopus:

… as a Latinization (through Greek Kanobos) from the Coptic Kahi Nub (“Golden Earth”), which refers to how Canopus would have appeared over the southern desert horizon in ancient Egypt, reddened by atmospheric absorption.

And it’s true … from much of the classical world in ancient times, Canopus would have appeared low in the sky, when it was visible at all. And so, yes, its bright light would be reddened due to looking at it through a greater thickness of atmosphere in the direction toward the horizon. Just as, for example, our sun or moon seen low in the sky looks redder than usual. Golden Earth indeed.

By the way, although Arrakis is fictional, Canopus is not only very real but also much hotter and larger than our sun.

History and mythology

Canopus is also called Alpha Carinae, the brightest star in the constellation Carina the Keel. This constellation used to be considered part of Argo Navis, the ship of Jason and his famed Argonauts, as seen in our sky. Canopus originally marked a keel or rudder of this ancient celestial ship. Alas, the great Argo Navis constellation no longer exists. Modern imaginations see it as broken into three parts: the Keel (Carina, of which Canopus is part), sails (Vela) and the poop deck (Puppis).

For those far enough south to see it, Canopus was a star of great importance from ancient times to modern times as a primary navigational star. This is, surely, due to its brightness.

The origin of the name Canopus is subject to question. By some accounts it is the name of a ship’s captain from the Trojan War. Another theory is that it is from ancient Egyptian meaning Golden Earth. It’s a possible reference to the star’s appearance as seen through atmospheric haze near the horizon from Egyptian latitudes.

The position of Canopus is RA: 6h 23m 57s, Dec: -52° 41′ 45″

Drawing from Urania’s Mirror, 1824. Carina is part of the ancient ship Argo Navis in the lower right corner. Image via Sidney Hall/ Wikipedia (public domain).

Bottom line: Canopus is the 2nd-brightest star as seen from Earth. To see Canopus, you must either be in the Southern Hemisphere or below the Northern Hemisphere’s 37th parallel north.

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The post Can you see Canopus, the 2nd-brightest star? first appeared on EarthSky.

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The gliding possum is a nocturnal acrobat of the forest

Discover the amazing gliding possum with EarthSky’s Cristina Ortiz.

Imagine an animal that can glide more than 165 feet (50 m) without flapping its limbs, with eyes so large they seem to capture the entire night, and that carries its young in a pouch like a kangaroo. It’s not a fantasy creature: it’s the gliding possum. This arboreal marsupial turns the nighttime forest into an airborne highway.

Although many confuse gliding possums with flying squirrels, they are not related. The gliding possum is not a rodent; it’s a marsupial, which changes the story completely. Here are the secrets of one of Oceania’s most fascinating mammals.

Anatomy of a nocturnal acrobat

The gliding possum is a small marsupial with a light, flexible body adapted to life in the trees. Depending on the species, its size varies considerably, from the tiny pygmy gliding possum (Acrobates pygmaeus), weighing just over 0.35 ounces (10 g), to the greater gliders, which can reach up to 3.5 pounds (1.6 kg) in weight.

The pygmy gliding possum is also called feathertail glider because of its distinctive tail with a “feathered” appearance. Image via Tony Rees/ Wikipedia (CC BY-SA 4.0).

Its fur is usually soft and dense, in shades of gray or brown, often with a darker stripe along the back. The tail is long, furry and highly functional. It acts as a rudder during gliding and as a balance aid when moving along branches.

Its limbs are equipped with long, exceptionally agile fingers that end in sharp claws. The gliding possum can grip tree bark, climb safely and maneuver precisely among branches.

As a true marsupial, the female has a ventral pouch where the young complete their development after an extremely premature birth. The tiny, undeveloped offspring cling inside the pouch for several weeks, feeding and growing. When they start venturing out, they practice climbing and exploring under the watchful eye of their mother, who protects and guides them in their first movements.

A greater glider holds onto a tree branch. Image via Josh Bowell/ Victorian National Parks Association/ Science NASA (CC BY 2.0).

The patagium acts as wings

The most astonishing feature of the gliding possum is the patagium, a thin skin membrane stretching from the forelimbs to the hindlimbs. When the animal extends its limbs, this membrane unfolds like a natural paraglider.

See that folded skin that separates the dark back from the white belly? That’s the patagium, a membrane that opens and acts as a paraglider. Image via Iachlancopeland/ iNaturalist (CC BY-SA 4.0).

Thanks to this adaptation, the gliding possum does not truly fly; it glides. It can launch from the top of a tree and travel up to 165 feet (50 m) before landing precisely on another trunk. While gliding, it adjusts its direction mainly using its limbs and tail, allowing it to navigate around obstacles and land accurately. Some species are capable of sharp, nearly 90-degree turns, helping them maneuver through dense forest canopies and evade predators. So the gliding possum’s efficient movement through trees also protects it from predation.

Big eyes, night vision

The possum’s enormous eyes are not merely aesthetic. They are essential adaptations to its nocturnal lifestyle.

Being primarily active at night, it needs to capture as much light as possible in dark environments. Its large eyeballs allow more light to reach the retina, improving vision in low-light conditions. This helps it locate food and anticipate predators.

Additionally, its vision is specially adapted to gauge distances accurately. This is crucial when jumping and gliding between trees high above the ground.

In addition to their exceptional eyesight, gliding possums rely heavily on smell and sensitive whiskers to navigate the forest at night. These senses help them detect obstacles, find food and move confidently even in near-total darkness.

Gliding possums are nocturnal animals. Therefore, they need big eyes to capture as much light as they can. Image via Timur Garifov/ Unsplash.

Forest friends in flight

Beyond gliding, these animals are full of surprising traits. Although often compared to flying squirrels, they are not rodents. They belong to the marsupial group, making them much more closely related to kangaroos and koalas than to any squirrel.

This small animal feeds on sap, nectar, fruit, insects and small invertebrates. Some species show remarkable behavior with food. They can carry small amounts in their mouths to eat later, almost like a portable pantry. They can also remember specific routes and trees that provide food, returning to the same trees year after year: a sign of exceptional spatial memory.

Although known for gliding, gliding possums can also leap vertically up to 6.5 feet (2 m) between nearby branches. They use this skill to evade predators or reach strategic launching points. Their constant activity among the trees is also a boon to the ecosystem. They transport pollen and disperse seeds, helping maintain forest balance. The gliding possum is an active and essential component of its ecosystem.

These marsupials feed on sap, nectar, fruit, insects and small invertebrates. While they move among the trees, they transport pollen and disperse seeds, contributing to forest health. Image via andyround62/ Pixabay.

Curious facts about the gliding possum

Another fascinating feature of gliding possums is their communication. They produce a wide range of sounds, including whistles, chirps and barely audible grunts. These noises help them stay in contact with their group and warn each other of danger. They are also highly social, sharing shelters, grooming one another and recognizing each family member by scent and sound.

In cold nights or when food is scarce, gliding possums can lower their metabolism and enter a state of torpor. This allows them conserve energy until conditions improve.

Gliding possums use a rich language to stay connected, share shelters, groom each other and navigate life together in the forest canopy. Image via Pfinge/ Wikipedia (CC BY-SA 2.0).

How many species of gliding possums exist?

Gliding possums belong to several genera within the order Diprotodontia, the largest living order of marsupials. They are the only marsupials capable of aerial gliding. More than 15 species are recognized, mainly in genera such as Petaurus, Petauroides, and Acrobates, along with a few minor genera.

Among them, the sugar glider (Petaurus breviceps) stands out as the most widely known species. Its popularity comes from both its wide distribution in Australia and New Guinea and its presence in the exotic pet trade. It is small, very social and active, which has contributed to its fame. But keeping it as a pet requires highly specific care.

At the opposite end in size is the southern greater glider (Petauroides volans), capable of spectacular glides among tall Australian forest trees.

From the tiny, social sugar glider to the soaring southern greater glider, these creatures are the only marsupails capable of true aerial gliding, spanning over 15 species across several genera. Image via Greg Tasney/ iNaturalist (CC BY-SA 4.0).

A fascinating and demanding animal

In recent years, the sugar glider has gained popularity as an exotic pet in various countries. Its small size, adorable appearance and active behavior make it appealing to those seeking a unique companion.

However, behind that cute image lies an animal with very specific needs. It is nocturnal, deeply social — living in small family groups and needing the company of other members of its species — and requires vertical space, constant stimulation and a complex diet difficult to replicate outside its natural habitat.

It is not a domesticated animal but a wild one. In the wild, these animals inhabit the vast forests of Australia and New Guinea, where vertical space and abundant trees make their aerial lifestyle possible.

When you understand their biology and behavior, you see the forest is where they’re meant to live. There, gliding among trees in the dark, the gliding possums display all the skills that make them one of nature’s most extraordinary little acrobats.

Sugar gliders are highly social, nocturnal wild animals with specialized needs. They thrive in forested habitats that allow them to glide, forage and live as nature intended. Image via naturalist67279/ iNaturalist.

Bottom line: Gliding possums dart through the night, soaring up to 165 feet with their young in their pouches. These tiny acrobats rule the treetops.

Read more: Koalas are our cute and furry lifeform of the week

Read more: Australian lyrebirds have a hidden skill for farming

The post The gliding possum is a nocturnal acrobat of the forest first appeared on EarthSky.

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Discover the amazing gliding possum with EarthSky’s Cristina Ortiz.

Imagine an animal that can glide more than 165 feet (50 m) without flapping its limbs, with eyes so large they seem to capture the entire night, and that carries its young in a pouch like a kangaroo. It’s not a fantasy creature: it’s the gliding possum. This arboreal marsupial turns the nighttime forest into an airborne highway.

Although many confuse gliding possums with flying squirrels, they are not related. The gliding possum is not a rodent; it’s a marsupial, which changes the story completely. Here are the secrets of one of Oceania’s most fascinating mammals.

Anatomy of a nocturnal acrobat

The gliding possum is a small marsupial with a light, flexible body adapted to life in the trees. Depending on the species, its size varies considerably, from the tiny pygmy gliding possum (Acrobates pygmaeus), weighing just over 0.35 ounces (10 g), to the greater gliders, which can reach up to 3.5 pounds (1.6 kg) in weight.

The pygmy gliding possum is also called feathertail glider because of its distinctive tail with a “feathered” appearance. Image via Tony Rees/ Wikipedia (CC BY-SA 4.0).

Its fur is usually soft and dense, in shades of gray or brown, often with a darker stripe along the back. The tail is long, furry and highly functional. It acts as a rudder during gliding and as a balance aid when moving along branches.

Its limbs are equipped with long, exceptionally agile fingers that end in sharp claws. The gliding possum can grip tree bark, climb safely and maneuver precisely among branches.

As a true marsupial, the female has a ventral pouch where the young complete their development after an extremely premature birth. The tiny, undeveloped offspring cling inside the pouch for several weeks, feeding and growing. When they start venturing out, they practice climbing and exploring under the watchful eye of their mother, who protects and guides them in their first movements.

A greater glider holds onto a tree branch. Image via Josh Bowell/ Victorian National Parks Association/ Science NASA (CC BY 2.0).

The patagium acts as wings

The most astonishing feature of the gliding possum is the patagium, a thin skin membrane stretching from the forelimbs to the hindlimbs. When the animal extends its limbs, this membrane unfolds like a natural paraglider.

See that folded skin that separates the dark back from the white belly? That’s the patagium, a membrane that opens and acts as a paraglider. Image via Iachlancopeland/ iNaturalist (CC BY-SA 4.0).

Thanks to this adaptation, the gliding possum does not truly fly; it glides. It can launch from the top of a tree and travel up to 165 feet (50 m) before landing precisely on another trunk. While gliding, it adjusts its direction mainly using its limbs and tail, allowing it to navigate around obstacles and land accurately. Some species are capable of sharp, nearly 90-degree turns, helping them maneuver through dense forest canopies and evade predators. So the gliding possum’s efficient movement through trees also protects it from predation.

Big eyes, night vision

The possum’s enormous eyes are not merely aesthetic. They are essential adaptations to its nocturnal lifestyle.

Being primarily active at night, it needs to capture as much light as possible in dark environments. Its large eyeballs allow more light to reach the retina, improving vision in low-light conditions. This helps it locate food and anticipate predators.

Additionally, its vision is specially adapted to gauge distances accurately. This is crucial when jumping and gliding between trees high above the ground.

In addition to their exceptional eyesight, gliding possums rely heavily on smell and sensitive whiskers to navigate the forest at night. These senses help them detect obstacles, find food and move confidently even in near-total darkness.

Gliding possums are nocturnal animals. Therefore, they need big eyes to capture as much light as they can. Image via Timur Garifov/ Unsplash.

Forest friends in flight

Beyond gliding, these animals are full of surprising traits. Although often compared to flying squirrels, they are not rodents. They belong to the marsupial group, making them much more closely related to kangaroos and koalas than to any squirrel.

This small animal feeds on sap, nectar, fruit, insects and small invertebrates. Some species show remarkable behavior with food. They can carry small amounts in their mouths to eat later, almost like a portable pantry. They can also remember specific routes and trees that provide food, returning to the same trees year after year: a sign of exceptional spatial memory.

Although known for gliding, gliding possums can also leap vertically up to 6.5 feet (2 m) between nearby branches. They use this skill to evade predators or reach strategic launching points. Their constant activity among the trees is also a boon to the ecosystem. They transport pollen and disperse seeds, helping maintain forest balance. The gliding possum is an active and essential component of its ecosystem.

These marsupials feed on sap, nectar, fruit, insects and small invertebrates. While they move among the trees, they transport pollen and disperse seeds, contributing to forest health. Image via andyround62/ Pixabay.

Curious facts about the gliding possum

Another fascinating feature of gliding possums is their communication. They produce a wide range of sounds, including whistles, chirps and barely audible grunts. These noises help them stay in contact with their group and warn each other of danger. They are also highly social, sharing shelters, grooming one another and recognizing each family member by scent and sound.

In cold nights or when food is scarce, gliding possums can lower their metabolism and enter a state of torpor. This allows them conserve energy until conditions improve.

Gliding possums use a rich language to stay connected, share shelters, groom each other and navigate life together in the forest canopy. Image via Pfinge/ Wikipedia (CC BY-SA 2.0).

How many species of gliding possums exist?

Gliding possums belong to several genera within the order Diprotodontia, the largest living order of marsupials. They are the only marsupials capable of aerial gliding. More than 15 species are recognized, mainly in genera such as Petaurus, Petauroides, and Acrobates, along with a few minor genera.

Among them, the sugar glider (Petaurus breviceps) stands out as the most widely known species. Its popularity comes from both its wide distribution in Australia and New Guinea and its presence in the exotic pet trade. It is small, very social and active, which has contributed to its fame. But keeping it as a pet requires highly specific care.

At the opposite end in size is the southern greater glider (Petauroides volans), capable of spectacular glides among tall Australian forest trees.

From the tiny, social sugar glider to the soaring southern greater glider, these creatures are the only marsupails capable of true aerial gliding, spanning over 15 species across several genera. Image via Greg Tasney/ iNaturalist (CC BY-SA 4.0).

A fascinating and demanding animal

In recent years, the sugar glider has gained popularity as an exotic pet in various countries. Its small size, adorable appearance and active behavior make it appealing to those seeking a unique companion.

However, behind that cute image lies an animal with very specific needs. It is nocturnal, deeply social — living in small family groups and needing the company of other members of its species — and requires vertical space, constant stimulation and a complex diet difficult to replicate outside its natural habitat.

It is not a domesticated animal but a wild one. In the wild, these animals inhabit the vast forests of Australia and New Guinea, where vertical space and abundant trees make their aerial lifestyle possible.

When you understand their biology and behavior, you see the forest is where they’re meant to live. There, gliding among trees in the dark, the gliding possums display all the skills that make them one of nature’s most extraordinary little acrobats.

Sugar gliders are highly social, nocturnal wild animals with specialized needs. They thrive in forested habitats that allow them to glide, forage and live as nature intended. Image via naturalist67279/ iNaturalist.

Bottom line: Gliding possums dart through the night, soaring up to 165 feet with their young in their pouches. These tiny acrobats rule the treetops.

Read more: Koalas are our cute and furry lifeform of the week

Read more: Australian lyrebirds have a hidden skill for farming

The post The gliding possum is a nocturnal acrobat of the forest first appeared on EarthSky.

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Chelyabinsk meteor: February 15, 2013

EarthSky’s 2026 lunar calendar shows the moon phase for every day of the year. Get yours today!

Chelyabinsk: a mid-sky asteroid explosion

On February 15, 2013, a small asteroid with an estimated size of 65 feet (20 meters) entered Earth’s atmosphere. It was moving at 12 miles per second (~19 km/sec) when it struck the protective blanket of air around our planet, which did its job and caused the asteroid to explode. The bright, hot explosion took place only about 20 miles (30 km) above the city of Chelyabinsk in Russia and carried 20 to 30 times the energy of the Hiroshima atomic bomb. Its shock wave broke windows and knocked down parts of buildings in six Russian cities; furthermore, it caused some 1,500 people to seek medical attention for injuries, mostly from flying glass.

Bright fireball over Russia on the morning of February 15, 2013. Scientists later said the light from the Chelyabinsk meteor was brighter than the sun. People saw it up to 60 miles (100 km) away.

The power of the Chelyabinsk explosion

Large and small bodies from space strike Earth’s atmosphere continuously. The Nuclear Test Ban Treaty Organization operates a network of sensors that monitors Earth around the clock listening for the infrasound signature of nuclear detonations. In 2014 it stated that the sensors had recorded 26 atom-bomb-scale asteroid impacts to Earth’s atmosphere since 2000.

Still, the February 15, 2013, Russian superbolide was extremely powerful; in fact, it was the most powerful explosion caused by an asteroid since Tunguska. The Tunguska event flattened a wide area of forest and killed reindeer in Siberia in 1908.

The Tunguska event happened in a sparsely populated part of Siberia; therefore, it remained mysterious to scientists throughout the early part of the 20th century. By contrast, across a wide swath of Russia on February 15, 2013, numerous dashboard cameras and amateur photographers captured images of the incoming meteor and its effects.

Vapor cloud trail left by the Chelyabinsk, Russia, asteroid as captured by M. Ahmetvaleev on February 15, 2013. Image via ESA.

Meteorites left by the explosion

After the 2013 meteor exploded, local residents and schoolchildren found meteorite fragments left in its aftermath, many located in snowdrifts. An informal market emerged for meteorite fragments.

A large number of small meteorites fell on areas west of Chelyabinsk, and, within hours of the visual sighting of the meteor, a 20-foot (6-meter) hole was discovered on the frozen surface of Lake Chebarkul in the Russian Ural Mountains. Scientists from the Ural Federal University collected 53 samples from around the hole that same day.

In June 2013, Russian scientists reported further investigation by magnetic imaging below the location of the ice hole in Lake Chebarkul. They identified a larger meteorite buried in sediments on the lake floor.

Following an operation lasting a number of weeks, on October 15, 2013, the scientists pulled up a large fragment of the meteorite from the bottom of Lake Chebarkul. It had a total mass of 1,442 pounds (654 kg) and to date remains the largest found fragment of the Chelyabinsk meteorite.

This is the largest-discovered fragment of the Russian meteorite, lifted from the bed of Lake Chebarkul in the Urals. Image via Voice of Russia.

Tracking the plume in the atmosphere

NASA satellites were also able to track the meteor plume in Earth’s atmosphere. As the video below describes, they tracked and studied the meteor plume for months.

Bottom line: On February 15, 2013, a small asteroid entered Earth’s atmosphere over Russia. Dash cam footage captured the bright meteor’s explosion over the city of Chelyabinsk.

How big are asteroids? Compare sizes in this video

Simulate asteroid impacts here

The post Chelyabinsk meteor: February 15, 2013 first appeared on EarthSky.

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EarthSky’s 2026 lunar calendar shows the moon phase for every day of the year. Get yours today!

Chelyabinsk: a mid-sky asteroid explosion

On February 15, 2013, a small asteroid with an estimated size of 65 feet (20 meters) entered Earth’s atmosphere. It was moving at 12 miles per second (~19 km/sec) when it struck the protective blanket of air around our planet, which did its job and caused the asteroid to explode. The bright, hot explosion took place only about 20 miles (30 km) above the city of Chelyabinsk in Russia and carried 20 to 30 times the energy of the Hiroshima atomic bomb. Its shock wave broke windows and knocked down parts of buildings in six Russian cities; furthermore, it caused some 1,500 people to seek medical attention for injuries, mostly from flying glass.

Bright fireball over Russia on the morning of February 15, 2013. Scientists later said the light from the Chelyabinsk meteor was brighter than the sun. People saw it up to 60 miles (100 km) away.

The power of the Chelyabinsk explosion

Large and small bodies from space strike Earth’s atmosphere continuously. The Nuclear Test Ban Treaty Organization operates a network of sensors that monitors Earth around the clock listening for the infrasound signature of nuclear detonations. In 2014 it stated that the sensors had recorded 26 atom-bomb-scale asteroid impacts to Earth’s atmosphere since 2000.

Still, the February 15, 2013, Russian superbolide was extremely powerful; in fact, it was the most powerful explosion caused by an asteroid since Tunguska. The Tunguska event flattened a wide area of forest and killed reindeer in Siberia in 1908.

The Tunguska event happened in a sparsely populated part of Siberia; therefore, it remained mysterious to scientists throughout the early part of the 20th century. By contrast, across a wide swath of Russia on February 15, 2013, numerous dashboard cameras and amateur photographers captured images of the incoming meteor and its effects.

Vapor cloud trail left by the Chelyabinsk, Russia, asteroid as captured by M. Ahmetvaleev on February 15, 2013. Image via ESA.

Meteorites left by the explosion

After the 2013 meteor exploded, local residents and schoolchildren found meteorite fragments left in its aftermath, many located in snowdrifts. An informal market emerged for meteorite fragments.

A large number of small meteorites fell on areas west of Chelyabinsk, and, within hours of the visual sighting of the meteor, a 20-foot (6-meter) hole was discovered on the frozen surface of Lake Chebarkul in the Russian Ural Mountains. Scientists from the Ural Federal University collected 53 samples from around the hole that same day.

In June 2013, Russian scientists reported further investigation by magnetic imaging below the location of the ice hole in Lake Chebarkul. They identified a larger meteorite buried in sediments on the lake floor.

Following an operation lasting a number of weeks, on October 15, 2013, the scientists pulled up a large fragment of the meteorite from the bottom of Lake Chebarkul. It had a total mass of 1,442 pounds (654 kg) and to date remains the largest found fragment of the Chelyabinsk meteorite.

This is the largest-discovered fragment of the Russian meteorite, lifted from the bed of Lake Chebarkul in the Urals. Image via Voice of Russia.

Tracking the plume in the atmosphere

NASA satellites were also able to track the meteor plume in Earth’s atmosphere. As the video below describes, they tracked and studied the meteor plume for months.

Bottom line: On February 15, 2013, a small asteroid entered Earth’s atmosphere over Russia. Dash cam footage captured the bright meteor’s explosion over the city of Chelyabinsk.

How big are asteroids? Compare sizes in this video

Simulate asteroid impacts here

The post Chelyabinsk meteor: February 15, 2013 first appeared on EarthSky.

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Mercury is farthest from the sunset February 19

Mercury isn’t as blazingly bright as Venus, but you can catch it in the western twilight now. It’ll climb away from Venus until February 19, then begin dropping back toward the sunset horizon. Saturn is also nearby. It’s slowly creeping closer to Venus, Mercury and the western horizon as the month goes by. Chart via EarthSky.

February 2026 is a great (though brief) opportunity to see the most elusive planet, Mercury. As our sun’s innermost planet, Mercury always lies near the sun in our sky. This small, speedy planet is now in the west after sunset. It’ll reach its greatest elongation, its greatest apparent distance from the sun in our sky on February 19, 2026. Just don’t mistake Mercury for the blazing planet Venus – or for much-fainter Saturn – which are also in the west in evening twilight.

Mercury after sunset in February 2026

Where to look: Look west, in the sunset direction – shortly after sunset – for Mercury. Venus is up there, too, blazing away at -3.9 magnitude. So the very bright one is Venus. From mid- to late February, Mercury is above Venus in the evening twilight sky. And Saturn is higher up still. The ecliptic – or path of the sun, moon and planets in our sky – is nearly perpendicular to the western horizon after sunset in spring. So, for the Northern Hemisphere, this is Mercury’s best evening apparition of 2026. Watch for the moon near Mercury on the evening of February 18.
Greatest elongation: Mercury is farthest from the sun on our sky’s dome at 18 UTC (1 p.m. CST) on February 19, 2026. At that time, Mercury will be 18 degrees from the sun in our sky. See a comparison of elongations, below.
Brightness: Mercury emerged in the evening sky early in February. Since then, it’s been shining at around -1.0 magnitude. At greatest elongation it’ll be farther from the sunset glare, shining around 0 magnitude and therefore brighter than most stars! In the evenings after greatest elongation, the innermost planet will rapidly fade. It’ll be moving between Earth and the sun, with its illuminated side becoming less and less visible. It’ll disappear early next month and will reach inferior conjunction – when it passes between Earth and the sun – at 11 UTC on March 7.
Through a telescope: Mercury will appear about 48% illuminated at greatest elongation. It’ll measure 7.18 arcseconds across.
Constellation: Mercury will lie in front of the constellation Pisces the Fish at this elongation. Doubtless, the stars in this constellation will be lost in the twilight.
Note: As the innermost planet, Mercury is tied to the sun in our sky. As a result, it never ventures very far above the horizon after sunset. So as soon as the sun disappears below your horizon, your clock starts ticking. Will you see the glowing point of light that is Mercury before it drops below the horizon, following the setting sun?

For precise sun and Mercury rising times at your location:

timeanddate.com (worldwide)
Stellarium (online planetarium)

Mercury events in 2026

Note: Times are in UTC

Jan 21, 2026: Superior conjunction (passes behind sun from Earth)
Feb 19, 2026: Greatest elongation (evening)
Mar 7, 2026: Inferior conjunction (races between Earth and sun)
Apr 3, 2026: Greatest elongation (morning)
May 14, 2026: Superior conjunction (passes behind sun from Earth)
Jun 15, 2026: Greatest elongation (evening)
Jul 13, 2026: Inferior conjunction (races between Earth and sun)
Aug 2, 2026: Greatest elongation (morning)
Aug 27, 2026: Superior conjunction (passes behind sun from Earth)
Oct 12, 2026: Greatest elongation (evening)
Nov 4, 2026: Inferior conjunction (races between Earth and sun)
Nov 21, 2026: Greatest elongation (morning)

At greatest elongation, Mercury is to one side of the sun and is at its greatest distance from the sun on our sky’s dome. Mercury reaches greatest eastern (evening) elongation from the sun at 18 UTC on February 19, 2026. That’s 1 p.m. CST. It’s then 18 degrees from the sun in the evening sky. This will be the best evening apparition of Mercury for the Northern Hemisphere in 2026. Chart via EarthSky.

Heliocentric view of Mercury February 2026

Heliocentric view of solar system, February 2026. Chart via Guy Ottewell’s 2026 Astronomical Calendar. Used with permission. Plus Guy Ottewell explains heliocentric charts here.

A comparison of elongations

In February 2026, Mercury stretches out 18 degrees from the sun in our sky. In fact, the farthest from the sun that Mercury can ever appear on the sky’s dome is about 28 degrees. And the least distance is around 18 degrees.

Mercury (and Venus) elongations are better or worse depending on the time of the year they occur. So in 2026, the Northern Hemisphere will have the best evening apparition in February. And the Southern Hemisphere will have its best evening elongation of Mercury in June.

In the autumn for either hemisphere, the ecliptic – or path of the sun, moon and planets – makes a narrow angle to the horizon in the evening. But it makes a steep slant, nearly perpendicular, in the morning. So, in autumn from either hemisphere, morning elongations of Mercury are best. That’s when Mercury appears higher above the horizon and farther from the glow of the sun. However, evening elongations in autumn are harder to see.

In the spring for either hemisphere, the situation reverses. The ecliptic and horizon meet at a sharper angle on spring evenings and a narrower angle on spring mornings. So, in springtime for either hemisphere, evening elongations of Mercury are best. Meanwhile, morning elongations in springtime are harder to see.

Mercury elongations compared. Here, gray areas represent evening apparitions (eastward elongation). Blue areas represent morning apparitions (westward elongation). The top figures are the maximum elongations, reached at the top dates shown beneath. Curves show the altitude of the planet above the horizon at sunrise or sunset, for latitude 40 degrees north (thick line) and 35 degrees south (thin line). Likewise, maxima are reached at the parenthesized dates below (40 degrees north in bold). Chart via Guy Ottewell’s 2026 Astronomical Calendar. Used with permission.

More Mercury evening elongation comparisons for 2026

Mercury’s greatest evening elongations in 2026 from the Northern Hemisphere as viewed through a powerful telescope. The planet images are at the 1st, 11th, and 21st of each month. Dots show the actual positions of the planet for every day. Chart via Guy Ottewell’s 2026 Astronomical Calendar. Used with permission.

Mercury’s greatest evening elongations in 2026 from the Southern Hemisphere as viewed through a powerful telescope. The planet images are at the 1st, 11th, and 21st of each month. Dots show the actual positions of the planet for every day. Chart via Guy Ottewell’s 2026 Astronomical Calendar. Used with permission.

Bottom line: The sun’s innermost planet, Mercury, will be 18 degrees from the sunset when it reaches its greatest elongation at 18 UTC on February 19. Also, this is the best evening apparition of Mercury in 2026 for the Northern Hemisphere.

Submit your photos to EarthSky here.

Read about greatest elongations, superior and inferior conjunctions: Definitions for stargazers

The post Mercury is farthest from the sunset February 19 first appeared on EarthSky.

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Mercury isn’t as blazingly bright as Venus, but you can catch it in the western twilight now. It’ll climb away from Venus until February 19, then begin dropping back toward the sunset horizon. Saturn is also nearby. It’s slowly creeping closer to Venus, Mercury and the western horizon as the month goes by. Chart via EarthSky.

February 2026 is a great (though brief) opportunity to see the most elusive planet, Mercury. As our sun’s innermost planet, Mercury always lies near the sun in our sky. This small, speedy planet is now in the west after sunset. It’ll reach its greatest elongation, its greatest apparent distance from the sun in our sky on February 19, 2026. Just don’t mistake Mercury for the blazing planet Venus – or for much-fainter Saturn – which are also in the west in evening twilight.

Mercury after sunset in February 2026

Where to look: Look west, in the sunset direction – shortly after sunset – for Mercury. Venus is up there, too, blazing away at -3.9 magnitude. So the very bright one is Venus. From mid- to late February, Mercury is above Venus in the evening twilight sky. And Saturn is higher up still. The ecliptic – or path of the sun, moon and planets in our sky – is nearly perpendicular to the western horizon after sunset in spring. So, for the Northern Hemisphere, this is Mercury’s best evening apparition of 2026. Watch for the moon near Mercury on the evening of February 18.
Greatest elongation: Mercury is farthest from the sun on our sky’s dome at 18 UTC (1 p.m. CST) on February 19, 2026. At that time, Mercury will be 18 degrees from the sun in our sky. See a comparison of elongations, below.
Brightness: Mercury emerged in the evening sky early in February. Since then, it’s been shining at around -1.0 magnitude. At greatest elongation it’ll be farther from the sunset glare, shining around 0 magnitude and therefore brighter than most stars! In the evenings after greatest elongation, the innermost planet will rapidly fade. It’ll be moving between Earth and the sun, with its illuminated side becoming less and less visible. It’ll disappear early next month and will reach inferior conjunction – when it passes between Earth and the sun – at 11 UTC on March 7.
Through a telescope: Mercury will appear about 48% illuminated at greatest elongation. It’ll measure 7.18 arcseconds across.
Constellation: Mercury will lie in front of the constellation Pisces the Fish at this elongation. Doubtless, the stars in this constellation will be lost in the twilight.
Note: As the innermost planet, Mercury is tied to the sun in our sky. As a result, it never ventures very far above the horizon after sunset. So as soon as the sun disappears below your horizon, your clock starts ticking. Will you see the glowing point of light that is Mercury before it drops below the horizon, following the setting sun?

For precise sun and Mercury rising times at your location:

timeanddate.com (worldwide)
Stellarium (online planetarium)

Mercury events in 2026

Note: Times are in UTC

Jan 21, 2026: Superior conjunction (passes behind sun from Earth)
Feb 19, 2026: Greatest elongation (evening)
Mar 7, 2026: Inferior conjunction (races between Earth and sun)
Apr 3, 2026: Greatest elongation (morning)
May 14, 2026: Superior conjunction (passes behind sun from Earth)
Jun 15, 2026: Greatest elongation (evening)
Jul 13, 2026: Inferior conjunction (races between Earth and sun)
Aug 2, 2026: Greatest elongation (morning)
Aug 27, 2026: Superior conjunction (passes behind sun from Earth)
Oct 12, 2026: Greatest elongation (evening)
Nov 4, 2026: Inferior conjunction (races between Earth and sun)
Nov 21, 2026: Greatest elongation (morning)

At greatest elongation, Mercury is to one side of the sun and is at its greatest distance from the sun on our sky’s dome. Mercury reaches greatest eastern (evening) elongation from the sun at 18 UTC on February 19, 2026. That’s 1 p.m. CST. It’s then 18 degrees from the sun in the evening sky. This will be the best evening apparition of Mercury for the Northern Hemisphere in 2026. Chart via EarthSky.

Heliocentric view of Mercury February 2026

Heliocentric view of solar system, February 2026. Chart via Guy Ottewell’s 2026 Astronomical Calendar. Used with permission. Plus Guy Ottewell explains heliocentric charts here.

A comparison of elongations

In February 2026, Mercury stretches out 18 degrees from the sun in our sky. In fact, the farthest from the sun that Mercury can ever appear on the sky’s dome is about 28 degrees. And the least distance is around 18 degrees.

Mercury (and Venus) elongations are better or worse depending on the time of the year they occur. So in 2026, the Northern Hemisphere will have the best evening apparition in February. And the Southern Hemisphere will have its best evening elongation of Mercury in June.

In the autumn for either hemisphere, the ecliptic – or path of the sun, moon and planets – makes a narrow angle to the horizon in the evening. But it makes a steep slant, nearly perpendicular, in the morning. So, in autumn from either hemisphere, morning elongations of Mercury are best. That’s when Mercury appears higher above the horizon and farther from the glow of the sun. However, evening elongations in autumn are harder to see.

In the spring for either hemisphere, the situation reverses. The ecliptic and horizon meet at a sharper angle on spring evenings and a narrower angle on spring mornings. So, in springtime for either hemisphere, evening elongations of Mercury are best. Meanwhile, morning elongations in springtime are harder to see.

Mercury elongations compared. Here, gray areas represent evening apparitions (eastward elongation). Blue areas represent morning apparitions (westward elongation). The top figures are the maximum elongations, reached at the top dates shown beneath. Curves show the altitude of the planet above the horizon at sunrise or sunset, for latitude 40 degrees north (thick line) and 35 degrees south (thin line). Likewise, maxima are reached at the parenthesized dates below (40 degrees north in bold). Chart via Guy Ottewell’s 2026 Astronomical Calendar. Used with permission.

More Mercury evening elongation comparisons for 2026

Mercury’s greatest evening elongations in 2026 from the Northern Hemisphere as viewed through a powerful telescope. The planet images are at the 1st, 11th, and 21st of each month. Dots show the actual positions of the planet for every day. Chart via Guy Ottewell’s 2026 Astronomical Calendar. Used with permission.

Mercury’s greatest evening elongations in 2026 from the Southern Hemisphere as viewed through a powerful telescope. The planet images are at the 1st, 11th, and 21st of each month. Dots show the actual positions of the planet for every day. Chart via Guy Ottewell’s 2026 Astronomical Calendar. Used with permission.

Bottom line: The sun’s innermost planet, Mercury, will be 18 degrees from the sunset when it reaches its greatest elongation at 18 UTC on February 19. Also, this is the best evening apparition of Mercury in 2026 for the Northern Hemisphere.

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Read about greatest elongations, superior and inferior conjunctions: Definitions for stargazers

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Pale Blue Dot 36 years later: Earth in a sunbeam

View larger. | In this image from Voyager 1 – acquired on February 14, 1990, from a distance slightly past the orbit of Saturn – planet Earth appears as a pale blue dot within the sunbeam, just right of center. As you can see, the blue glow of Earth occupies less than a single pixel so it’s not fully resolved. Image via NASA.

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February 14, 1990: the Pale Blue Dot

The Voyager 1 spacecraft, out near Saturn, took this iconic image of Earth 36 years ago. It turned out to be one of the most memorable images ever taken from space. Astronomer Carl Sagan wrote in his 1994 book Pale Blue Dot:

Look again at that dot. That’s here. That’s home. That’s us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives. The aggregate of our joy and suffering, thousands of confident religions, ideologies, and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilization, every king and peasant, every young couple in love, every mother and father, hopeful child, inventor and explorer, every teacher of morals, every corrupt politician, every ‘superstar,’ every ‘supreme leader,’ every saint and sinner in the history of our species lived there – on a mote of dust suspended in a sunbeam.

An updated look at the Pale Blue Dot

NASA said on February 12, 2020, that it updated the Pale Blue Dot image, using modern image-processing software and techniques. NASA explained:

… the Voyager project planned to shut off the Voyager 1 spacecraft’s imaging cameras to conserve power because the probe – along with its sibling Voyager 2 – would not fly close enough to any other objects to take pictures. Before the shutdown, the mission commanded the probe to take a series of 60 images designed to produce what they termed the Family Portrait of the Solar System. Executed on Valentine’s Day 1990, this sequence returned images for making color views of six of the solar system’s planets and also imaged the sun in monochrome.

Carl Sagan named the image

The popular name of this view comes from the title of the 1994 book by Voyager imaging scientist Carl Sagan. He originated the idea of using Voyager’s cameras to image the distant Earth and played a critical role in getting the family portrait taken.

The direction of the sun is toward the bottom of the view (where the image is brightest). Rays of sunlight scattered within the camera optics stretch across the scene. By coincidence, one of those light rays intersects dramatically with Earth.

From Voyager 1’s vantage point – a distance of approximately 3.8 billion miles (6 billion km) – Earth appears separated from the sun by only a few degrees. The close proximity of the inner planets to the sun was a key factor as to why engineers couldn’t take these images earlier in the mission. At that time, our star was still close and bright enough to damage the cameras with its blinding glare.

Scientists combined green, blue and violet spectral filters from the Voyager 1 Narrow-Angle Camera for this composite. Voyager took these photos at 4:48 UTC on February 14, 1990. That was just 34 minutes before Voyager 1 powered off its cameras forever.

Our family portrait

View larger. | The Family Portrait of the Solar System. Voyager 1 acquired this series of 60 images on February 14, 1990. Image via NASA.

View larger. | This simulated view from NASA’s Eyes on the Solar System app shows Voyager 1’s perspective when it took its final series of images. This Family Portrait of the Solar System includes the Pale Blue Dot image. Image via NASA.

Bottom line: February 14, 2026, is the 36th anniversary of the Voyager 1 image of Earth. Voyager was near Saturn when it took this image, which is now known as the Pale Blue Dot.

Via NASA

Read more: Hera spots Earth and the moon from space. See it here!

Read more: Earth images from space: 10 incredible photos of our planet

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View larger. | In this image from Voyager 1 – acquired on February 14, 1990, from a distance slightly past the orbit of Saturn – planet Earth appears as a pale blue dot within the sunbeam, just right of center. As you can see, the blue glow of Earth occupies less than a single pixel so it’s not fully resolved. Image via NASA.

EarthSky’s 2026 lunar calendar shows the moon phase for every day of the year. Get yours today!

February 14, 1990: the Pale Blue Dot

The Voyager 1 spacecraft, out near Saturn, took this iconic image of Earth 36 years ago. It turned out to be one of the most memorable images ever taken from space. Astronomer Carl Sagan wrote in his 1994 book Pale Blue Dot:

Look again at that dot. That’s here. That’s home. That’s us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives. The aggregate of our joy and suffering, thousands of confident religions, ideologies, and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilization, every king and peasant, every young couple in love, every mother and father, hopeful child, inventor and explorer, every teacher of morals, every corrupt politician, every ‘superstar,’ every ‘supreme leader,’ every saint and sinner in the history of our species lived there – on a mote of dust suspended in a sunbeam.

An updated look at the Pale Blue Dot

NASA said on February 12, 2020, that it updated the Pale Blue Dot image, using modern image-processing software and techniques. NASA explained:

… the Voyager project planned to shut off the Voyager 1 spacecraft’s imaging cameras to conserve power because the probe – along with its sibling Voyager 2 – would not fly close enough to any other objects to take pictures. Before the shutdown, the mission commanded the probe to take a series of 60 images designed to produce what they termed the Family Portrait of the Solar System. Executed on Valentine’s Day 1990, this sequence returned images for making color views of six of the solar system’s planets and also imaged the sun in monochrome.

Carl Sagan named the image

The popular name of this view comes from the title of the 1994 book by Voyager imaging scientist Carl Sagan. He originated the idea of using Voyager’s cameras to image the distant Earth and played a critical role in getting the family portrait taken.

The direction of the sun is toward the bottom of the view (where the image is brightest). Rays of sunlight scattered within the camera optics stretch across the scene. By coincidence, one of those light rays intersects dramatically with Earth.

From Voyager 1’s vantage point – a distance of approximately 3.8 billion miles (6 billion km) – Earth appears separated from the sun by only a few degrees. The close proximity of the inner planets to the sun was a key factor as to why engineers couldn’t take these images earlier in the mission. At that time, our star was still close and bright enough to damage the cameras with its blinding glare.

Scientists combined green, blue and violet spectral filters from the Voyager 1 Narrow-Angle Camera for this composite. Voyager took these photos at 4:48 UTC on February 14, 1990. That was just 34 minutes before Voyager 1 powered off its cameras forever.

Our family portrait

View larger. | The Family Portrait of the Solar System. Voyager 1 acquired this series of 60 images on February 14, 1990. Image via NASA.

View larger. | This simulated view from NASA’s Eyes on the Solar System app shows Voyager 1’s perspective when it took its final series of images. This Family Portrait of the Solar System includes the Pale Blue Dot image. Image via NASA.

Bottom line: February 14, 2026, is the 36th anniversary of the Voyager 1 image of Earth. Voyager was near Saturn when it took this image, which is now known as the Pale Blue Dot.

Via NASA

Read more: Hera spots Earth and the moon from space. See it here!

Read more: Earth images from space: 10 incredible photos of our planet

The post Pale Blue Dot 36 years later: Earth in a sunbeam first appeared on EarthSky.

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Star dims for 9 months, likely due to giant ringed object

Artist’s impression of a star dimming due to its light being blocked by a giant ringed planet or possibly a brown dwarf. In this illustration, a super-Jupiter with massive rings in the foreground forms an opaque “saucer” through which some light from the star ASASSN-24fw shines. Scientists also discovered a neighboring red dwarf star during their research. Image via S. Shah et al./ Royal Astronomical Society (CC BY 4.0).

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• A star called ASASSN-24fw dimmed by 97% for more than nine months. It was one of the longest stellar dimming events ever recorded. But why did it get so dim for so long?
• Astronomers think an unseen brown dwarf or super-Jupiter with a huge ring system passed in front of the star, blocking its light.
• The researchers expect the star to dim again in about 42 or 43 years. At that time, astronomers can carry out further analysis to find out more about this fascinating system.

The Royal Astronomical Society published this original story on February 12, 2026. Edits by EarthSky.

Star dims for 9 months, likely due to giant ringed planet

One of the longest stellar dimming events ever observed was likely caused by the gigantic saucer-like rings of either an unseen “super-Jupiter” or a brown dwarf blocking its host star’s light. That’s according to astronomers at the Royal Astronomical Society, who described the new research on the fading star on February 12. 2026. The star, named ASASSN-24fw, sits 3,200 light-years from Earth and is about twice as big as our sun. For decades, astronomers had observed the star as stable, but at the end of 2024 it faded dramatically.

It then remained this way for more than nine months, far longer than is normal for an event like this. The unusual length of the dimming sparked confusion among researchers and prompted speculation as to what could have caused such an “extremely rare” phenomenon.

Now, in a new study published February 12, 2026, in the peer-reviewed Monthly Notices of the Royal Astronomical Society, a team of international researchers propose a solution of the riddle of this mysterious star in the Monoceros constellation.

They think it was most likely a brown dwarf (an object between the size of a star and Jupiter) with Saturn-like rings that caused ASASSN-24fw to dim by about 97%. This ring system is so enormous it extends out about 0.17 astronomical units (AU), comparable to half the distance between our sun and Mercury.

Brown dwarf or super-Jupiter

The two most likely objects responsible for blocking the star’s light are a brown dwarf or super-Jupiter.

Brown dwarfs are mysterious objects. They’re too big to be a planet but also too small to be a star. They lack the mass to keep fusing atoms and blossom into fully fledged suns.

The other option, the researchers said, is a super-Jupiter. These are massive gas giant exoplanets that exceed the mass of Jupiter and bridge the gap between brown dwarfs and planets.

Their findings offer a glimpse into complex planetary-scale structures beyond our solar system. And they pave a new way to study how planets and their rings may form and evolve around other stars.

Unlike typical eclipses, which usually last days or weeks, this dimming continued for nearly 200 days, making it one of the longest ever observed.

Lead author Sarang Shah, a post-doctoral researcher at the Inter-University Centre for Astronomy and Astrophysics (IUCAA), in Pune, India, said:

Various models made by our group show that the most likely explanation for the dimming is a brown dwarf – an object heavier than a planet but lighter than a star – surrounded by a vast and dense ring system. It is orbiting the star at a farther distance with the ring.

Long-lasting dimming events like this are exceptionally uncommon as they require very perfect lineups. The dimming began gradually because the outer parts of the rings are thin, and only became obvious when the denser regions passed in front of the star.

Artist’s impression of ASASSN-24fw after the eclipse is over. Now we can see the star shining unobstructed. And it also has a debris disk, possibly the remnants from a planetary collision. The unseen object with its huge rings is at lower right. A companion red dwarf star is at lower left. Image via S. Shah et al./ Royal Astronomical Society (CC BY 4.0).

Large ring system

Analysis of photometric and spectroscopic studies of the event suggests that the companion object has a mass of more than three times that of Jupiter.

The analysis also shows that ASASSN-24fw itself has a circumstellar environment (possibly remnants from past or ongoing planetary collisions) very near to it, which is unusual for a star of this age (likely more than 1 billion years).

Co-author Jonathan Marshall, an independent post-doctoral researcher affiliated with Academia Sinica, Taiwan, has expertise is in circumstellar material and debris discs. Marshall said:

Large ring systems are expected around massive objects, but they are very difficult to observe directly to determine their characteristics. This rare event allows us to study such a complex system in remarkable detail. In fact, while studying this dimming, we also serendipitously discovered that ASASSN-24fw also has a red dwarf star in its vicinity.

The team of researchers now want to measure the temperature, evolutionary status, chemical composition and age of the star that dimmed. They then hope to obtain more data from the European Southern Observatory’s Very Large Telescope in Chile and the James Webb Space Telescope to better understand the evolution of such systems and relate them to planetary formation theories.

The researchers expect the star to dim again in about 42 or 43 years’ time. At that time, astronomers can carry out further analysis to find out more about this fascinating system.

Bottom line: Astronomers watched a star dim to less than 97% of its brightness for nine months. They believe a giant ringed object blocked the light from our view.

Source: The nature of ASASSN-24fw’s occultation: modelling the event as dimming by optically thick rings around a sub-stellar companion

Via Royal Astronomical Society

The post Star dims for 9 months, likely due to giant ringed object first appeared on EarthSky.

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Artist’s impression of a star dimming due to its light being blocked by a giant ringed planet or possibly a brown dwarf. In this illustration, a super-Jupiter with massive rings in the foreground forms an opaque “saucer” through which some light from the star ASASSN-24fw shines. Scientists also discovered a neighboring red dwarf star during their research. Image via S. Shah et al./ Royal Astronomical Society (CC BY 4.0).

EarthSky’s 2026 lunar calendar shows the moon phase for every day of the year. Get yours today!

• A star called ASASSN-24fw dimmed by 97% for more than nine months. It was one of the longest stellar dimming events ever recorded. But why did it get so dim for so long?
• Astronomers think an unseen brown dwarf or super-Jupiter with a huge ring system passed in front of the star, blocking its light.
• The researchers expect the star to dim again in about 42 or 43 years. At that time, astronomers can carry out further analysis to find out more about this fascinating system.

The Royal Astronomical Society published this original story on February 12, 2026. Edits by EarthSky.

Star dims for 9 months, likely due to giant ringed planet

One of the longest stellar dimming events ever observed was likely caused by the gigantic saucer-like rings of either an unseen “super-Jupiter” or a brown dwarf blocking its host star’s light. That’s according to astronomers at the Royal Astronomical Society, who described the new research on the fading star on February 12. 2026. The star, named ASASSN-24fw, sits 3,200 light-years from Earth and is about twice as big as our sun. For decades, astronomers had observed the star as stable, but at the end of 2024 it faded dramatically.

It then remained this way for more than nine months, far longer than is normal for an event like this. The unusual length of the dimming sparked confusion among researchers and prompted speculation as to what could have caused such an “extremely rare” phenomenon.

Now, in a new study published February 12, 2026, in the peer-reviewed Monthly Notices of the Royal Astronomical Society, a team of international researchers propose a solution of the riddle of this mysterious star in the Monoceros constellation.

They think it was most likely a brown dwarf (an object between the size of a star and Jupiter) with Saturn-like rings that caused ASASSN-24fw to dim by about 97%. This ring system is so enormous it extends out about 0.17 astronomical units (AU), comparable to half the distance between our sun and Mercury.

Brown dwarf or super-Jupiter

The two most likely objects responsible for blocking the star’s light are a brown dwarf or super-Jupiter.

Brown dwarfs are mysterious objects. They’re too big to be a planet but also too small to be a star. They lack the mass to keep fusing atoms and blossom into fully fledged suns.

The other option, the researchers said, is a super-Jupiter. These are massive gas giant exoplanets that exceed the mass of Jupiter and bridge the gap between brown dwarfs and planets.

Their findings offer a glimpse into complex planetary-scale structures beyond our solar system. And they pave a new way to study how planets and their rings may form and evolve around other stars.

Unlike typical eclipses, which usually last days or weeks, this dimming continued for nearly 200 days, making it one of the longest ever observed.

Lead author Sarang Shah, a post-doctoral researcher at the Inter-University Centre for Astronomy and Astrophysics (IUCAA), in Pune, India, said:

Various models made by our group show that the most likely explanation for the dimming is a brown dwarf – an object heavier than a planet but lighter than a star – surrounded by a vast and dense ring system. It is orbiting the star at a farther distance with the ring.

Long-lasting dimming events like this are exceptionally uncommon as they require very perfect lineups. The dimming began gradually because the outer parts of the rings are thin, and only became obvious when the denser regions passed in front of the star.

Artist’s impression of ASASSN-24fw after the eclipse is over. Now we can see the star shining unobstructed. And it also has a debris disk, possibly the remnants from a planetary collision. The unseen object with its huge rings is at lower right. A companion red dwarf star is at lower left. Image via S. Shah et al./ Royal Astronomical Society (CC BY 4.0).

Large ring system

Analysis of photometric and spectroscopic studies of the event suggests that the companion object has a mass of more than three times that of Jupiter.

The analysis also shows that ASASSN-24fw itself has a circumstellar environment (possibly remnants from past or ongoing planetary collisions) very near to it, which is unusual for a star of this age (likely more than 1 billion years).

Co-author Jonathan Marshall, an independent post-doctoral researcher affiliated with Academia Sinica, Taiwan, has expertise is in circumstellar material and debris discs. Marshall said:

Large ring systems are expected around massive objects, but they are very difficult to observe directly to determine their characteristics. This rare event allows us to study such a complex system in remarkable detail. In fact, while studying this dimming, we also serendipitously discovered that ASASSN-24fw also has a red dwarf star in its vicinity.

The team of researchers now want to measure the temperature, evolutionary status, chemical composition and age of the star that dimmed. They then hope to obtain more data from the European Southern Observatory’s Very Large Telescope in Chile and the James Webb Space Telescope to better understand the evolution of such systems and relate them to planetary formation theories.

The researchers expect the star to dim again in about 42 or 43 years’ time. At that time, astronomers can carry out further analysis to find out more about this fascinating system.

Bottom line: Astronomers watched a star dim to less than 97% of its brightness for nine months. They believe a giant ringed object blocked the light from our view.

Source: The nature of ASASSN-24fw’s occultation: modelling the event as dimming by optically thick rings around a sub-stellar companion

Via Royal Astronomical Society

The post Star dims for 9 months, likely due to giant ringed object first appeared on EarthSky.

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