Taurid meteors in 2026: All you need to know

Taurid meteors consist of 2 streams, the South Taurids and North Taurids. Both streams radiate from the constellation Taurus the Bull, not far from the bright star Aldebaran and the tiny, misty, dipper-shaped Pleiades. Taurus is high in the sky in the middle of the night now. So the hours around midnight are a good time to watch for Taurid meteors and fireballs, as they appear to originate from the constellation Taurus. In October and November, this constellation is highest in the sky in the middle of the night.

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Taurid meteors in 2026

You might see South Taurid meteors any time from about September 10 to November 20. The North Taurids stem from a nearby but slightly different stream. They’re active from about October 20 to December 10. Both showers produce about five meteors per hour (10 total when they overlap) and some of them are fireballs.

Predicted peak: According the the RASC Observer’s Guide, the South Taurids’ predicted peak is for 19 UTC on November 5, 2026. The North Taurids’ predicted peak is for 18 UTC on November 12, 2026. Both the South and North Taurids don’t have very definite peaks. They ramble along in October and November and are especially noticeable from late October into early November, when they overlap.
When to watch: Best around midnight when the radiant is highest in the sky.
Overall duration of shower: The South Taurids run from about September 23 to November 12. This time period is when we’re passing through the Southern Taurid meteor stream in space. North Taurids are active from about October 13 to December 2. And this time period is when we’re passing through the Northern Taurid meteor stream in space.
Radiant: Rises in early evening, highest in the sky around midnight. See chart below.
Nearest moon phases: In 2026, the new moon falls at 7:02 UTC on November 9. So moonlight will not interfere with Taurid meteors in 2026. You’ll catch Taurid meteors throughout October and November. Visit Sunrise Sunset Calendars to see moon rising times for your location. Be sure to check the moon rising time box.
Expected meteors at peak, under ideal conditions: Under dark skies with no moon, both the South and North Taurid meteor showers produce about five meteors per hour (10 total when they overlap). Also, watch for fireballs. In most years, only 1% of all Taurid meteors are fireballs. In exceptional years, when the Earth passes through a concentrated field of debris, the percentage can be as high as 7%.
Note: Taurid meteors tend to be slow-moving but sometimes very bright. The showers sometimes produce fireballs, which made their cyclical reappearance in 2008, 2015 and 2022. The next predicted swarm or outburst of Taurid fireballs is in 2032.

Around now, watch for Taurid fireballs

The Taurid fireball display in 2015 was really fun! Photos and video of 2015 Taurid fireballs here.

Read more about Taurid fireballs in 2022

Report a fireball (very bright meteor) to the American Meteor Society: it’s fun and easy!

Read more: Veteran meteor photographer Eliot Herman’s website: Meteor Photography

The Northern Taurids parent comet

This section is by the late, great Don Machholz (1952-2022), who discovered 12 comets …

The object responsible for the Northern Taurid meteor shower is believed to be an asteroid. And that asteroid is related to a comet.

The asteroid is named 2004 TG10. The Spacewatch program discovered it on October 8, 2004. Its orbit around the sun closely matches that of periodic Comet Encke (officially known as 2P/Encke). Scientists believe this asteroid was once part of a much larger object known as the Encke Complex.

The most widely accepted theory is that about 20,000 years ago, a much larger object broke up, creating Comet Encke and several asteroids and meteor showers. Scientists named this group of resultant objects after the most prominent member of the group: Comet Encke. Hence, the Encke Complex.

No single asteroid produces Taurid meteors

A recent study indicates that the asteroid 2004 TG10 is only one of 10 related asteroids that may be responsible for this meteor shower. If that is true, then no single asteroid is producing the material causing the Northern Taurid meteors.

How is a mystery like this solved? Time and teamwork. Special nighttime video cameras record incoming meteors, and computers calculate the orbit almost immediately. Scientists compare these orbits to known objects, such as comets and asteroids. A direct match is unlikely, because any piece of material ejected from a comet or asteroid — perhaps hundreds of years ago — has been subjected to solar radiation and planetary perturbations that change its path around the sun. So, its final orbit, just before it enters our atmosphere, is likely different than the orbit it originated from. Astronomers who specialize in celestial mechanics will be the ones to bring us the solution.

Cameras and computers are likely to give us a better picture and a more thorough understanding of the Northern Taurids meteor shower.

The Southern Taurids parent comet

From Don Machholz …

The material we see as meteors from the Southern Taurids radiant comes from the comet known as Encke’s Comet. Officially known as 2P/Encke, this comet was discovered four times before it received its name.

The French comet hunter Pierre Mechian discovered it on January 17, 1786. He observed the comet for only three days and did not calculate its orbit. Next up was Caroline Herschel of England, who found it on November 7, 1795, 10 years later. She tracked it for 23 days but did not calculate an accurate orbit. Ten years later, Frenchman Jean-Louis Pons, the greatest visual comet hunter of all time, picked it up on October 20, 1805. Within hours of Pons’ discovery, Hofrath Huth of Germany and Alexis Bouvard in Paris picked it up too. This time they followed it for 32 days.

Enter Johann Franz Encke. Using these positions, he calculated an orbit for this comet and predicted that it would return. End of story? No, because he predicted it would return in 12.12 years. And it didn’t.

Tracking a new comet

Then, on November 26, 1818, Pons picked up a comet and tracked it for 48 days. Encke calculated an orbit for this one, and using some new computing techniques, came up with an orbital solution suggesting the comet takes only 3.3 years to go around the sun once. After six weeks of work, he was also able to link this comet to the comets of 1786, 1795 and 1805. He then correctly predicted that it would return in 1822. Based upon his work correctly calculating the comet’s orbit, the comet received the name Encke.

Comet Encke has the shortest orbital period of any major comet in our solar system. At its closest, it gets as close to the sun as does the planet Mercury, the planet closest to the sun. The orbit is stable, and the comet has probably been in the same orbit for thousands of years.

Was Comet Encke once part of a larger comet?

A recent theory is that Comet Encke was once part of a larger comet that broke up about 20,000 years ago. This event produced several small asteroids and the debris that now forms this meteor shower. And there are more. Scientists attribute at least three other meteor showers to Comet Encke. One stream of material might have delivered the object responsible for the Tunguska meteor event of 1908. This whole system is known as the Encke Complex.

Comet Encke, parent of the Taurid meteor showers. Image via NASA.

The next return of Comet Encke will be in July 2030.

What about Taurid fireballs?

Astronomers studying the Taurids found that Earth encounters a concentration of larger-than-normal debris at intervals of three or seven years resulting in a higher rate of fireballs.

The American Meteor Society said in 2022:

Taurid fireballs — visible in Earth’s skies in October and November — are often colorful. They often fragment as they streak slowly through the sky. In most years, only 1% of all Taurid meteors are fireballs. In exceptional years, when the Earth passes through a concentrated field of debris, the percentage can be as high as 7%. So visual observers and astrophotographers might see several fireballs each night instead of the normal rate of one every 20 hours.

And they were right! There were lots of fireball sightings in 2022.

The next predicted Taurid swarm is in 2032 and appears to be an exceptional year, as the moon will be new and Earth will pass very close to the center of the swarm.

Read more: Could Taurid fireballs – aka Halloween fireballs – bring a risk to Earth?

Why don’t the dates agree for Taurid meteors?

The story of the predicted peaks for the Taurids — which vary from place to place across the internet — is interesting. And a big reason is that astronomers are always learning new things.

For the most part, we count on the American Meteor Society and the Observer’s Handbook from the Royal Astronomical Society of Canada to provide us with the peak dates for the year’s major meteor showers.

So predicted peaks will vary. It’s nature! We don’t have it entirely pinned down.

View at EarthSky Community Photos. | Joel Weatherly in Edmonton, Alberta, Canada, created this composite from images captured on the morning of November 11, 2020. He wrote, “This is a composite image featuring Taurus and 4 meteors that I observed while out for the Northern Taurids meteor shower. The 2 brightest meteors left behind dust trails.” Thank you, Joel!

Bottom line: You might see a South Taurid meteor any time from about September 10 to November 20. That’s when Earth is plowing through the meteor stream – the stream of comet debris in space – that creates this meteor shower. The North Taurids stem from a nearby, but slightly different stream. They’re active from about October 20 to December 10. Both showers produce about five meteors per hour (10 total when they overlap).

**Predicted peak times and dates for meteor showers are from the American Meteor Society. Note that meteor shower peak times can vary.

Meteor showers: Tips for watching the show

Read more: Meteors in moonlight: 6 tips for watching

EarthSky’s meteor shower guide

The post Taurid meteors in 2026: All you need to know first appeared on EarthSky.

from EarthSky https://ift.tt/rhcbXuq

Taurid meteors consist of 2 streams, the South Taurids and North Taurids. Both streams radiate from the constellation Taurus the Bull, not far from the bright star Aldebaran and the tiny, misty, dipper-shaped Pleiades. Taurus is high in the sky in the middle of the night now. So the hours around midnight are a good time to watch for Taurid meteors and fireballs, as they appear to originate from the constellation Taurus. In October and November, this constellation is highest in the sky in the middle of the night.

Don’t miss the next spectacular sky event! Subscribe to EarthSky’s free daily newsletter for sky and science news.

Taurid meteors in 2026

You might see South Taurid meteors any time from about September 10 to November 20. The North Taurids stem from a nearby but slightly different stream. They’re active from about October 20 to December 10. Both showers produce about five meteors per hour (10 total when they overlap) and some of them are fireballs.

Predicted peak: According the the RASC Observer’s Guide, the South Taurids’ predicted peak is for 19 UTC on November 5, 2026. The North Taurids’ predicted peak is for 18 UTC on November 12, 2026. Both the South and North Taurids don’t have very definite peaks. They ramble along in October and November and are especially noticeable from late October into early November, when they overlap.
When to watch: Best around midnight when the radiant is highest in the sky.
Overall duration of shower: The South Taurids run from about September 23 to November 12. This time period is when we’re passing through the Southern Taurid meteor stream in space. North Taurids are active from about October 13 to December 2. And this time period is when we’re passing through the Northern Taurid meteor stream in space.
Radiant: Rises in early evening, highest in the sky around midnight. See chart below.
Nearest moon phases: In 2026, the new moon falls at 7:02 UTC on November 9. So moonlight will not interfere with Taurid meteors in 2026. You’ll catch Taurid meteors throughout October and November. Visit Sunrise Sunset Calendars to see moon rising times for your location. Be sure to check the moon rising time box.
Expected meteors at peak, under ideal conditions: Under dark skies with no moon, both the South and North Taurid meteor showers produce about five meteors per hour (10 total when they overlap). Also, watch for fireballs. In most years, only 1% of all Taurid meteors are fireballs. In exceptional years, when the Earth passes through a concentrated field of debris, the percentage can be as high as 7%.
Note: Taurid meteors tend to be slow-moving but sometimes very bright. The showers sometimes produce fireballs, which made their cyclical reappearance in 2008, 2015 and 2022. The next predicted swarm or outburst of Taurid fireballs is in 2032.

Around now, watch for Taurid fireballs

The Taurid fireball display in 2015 was really fun! Photos and video of 2015 Taurid fireballs here.

Read more about Taurid fireballs in 2022

Report a fireball (very bright meteor) to the American Meteor Society: it’s fun and easy!

Read more: Veteran meteor photographer Eliot Herman’s website: Meteor Photography

The Northern Taurids parent comet

This section is by the late, great Don Machholz (1952-2022), who discovered 12 comets …

The object responsible for the Northern Taurid meteor shower is believed to be an asteroid. And that asteroid is related to a comet.

The asteroid is named 2004 TG10. The Spacewatch program discovered it on October 8, 2004. Its orbit around the sun closely matches that of periodic Comet Encke (officially known as 2P/Encke). Scientists believe this asteroid was once part of a much larger object known as the Encke Complex.

The most widely accepted theory is that about 20,000 years ago, a much larger object broke up, creating Comet Encke and several asteroids and meteor showers. Scientists named this group of resultant objects after the most prominent member of the group: Comet Encke. Hence, the Encke Complex.

No single asteroid produces Taurid meteors

A recent study indicates that the asteroid 2004 TG10 is only one of 10 related asteroids that may be responsible for this meteor shower. If that is true, then no single asteroid is producing the material causing the Northern Taurid meteors.

How is a mystery like this solved? Time and teamwork. Special nighttime video cameras record incoming meteors, and computers calculate the orbit almost immediately. Scientists compare these orbits to known objects, such as comets and asteroids. A direct match is unlikely, because any piece of material ejected from a comet or asteroid — perhaps hundreds of years ago — has been subjected to solar radiation and planetary perturbations that change its path around the sun. So, its final orbit, just before it enters our atmosphere, is likely different than the orbit it originated from. Astronomers who specialize in celestial mechanics will be the ones to bring us the solution.

Cameras and computers are likely to give us a better picture and a more thorough understanding of the Northern Taurids meteor shower.

The Southern Taurids parent comet

From Don Machholz …

The material we see as meteors from the Southern Taurids radiant comes from the comet known as Encke’s Comet. Officially known as 2P/Encke, this comet was discovered four times before it received its name.

The French comet hunter Pierre Mechian discovered it on January 17, 1786. He observed the comet for only three days and did not calculate its orbit. Next up was Caroline Herschel of England, who found it on November 7, 1795, 10 years later. She tracked it for 23 days but did not calculate an accurate orbit. Ten years later, Frenchman Jean-Louis Pons, the greatest visual comet hunter of all time, picked it up on October 20, 1805. Within hours of Pons’ discovery, Hofrath Huth of Germany and Alexis Bouvard in Paris picked it up too. This time they followed it for 32 days.

Enter Johann Franz Encke. Using these positions, he calculated an orbit for this comet and predicted that it would return. End of story? No, because he predicted it would return in 12.12 years. And it didn’t.

Tracking a new comet

Then, on November 26, 1818, Pons picked up a comet and tracked it for 48 days. Encke calculated an orbit for this one, and using some new computing techniques, came up with an orbital solution suggesting the comet takes only 3.3 years to go around the sun once. After six weeks of work, he was also able to link this comet to the comets of 1786, 1795 and 1805. He then correctly predicted that it would return in 1822. Based upon his work correctly calculating the comet’s orbit, the comet received the name Encke.

Comet Encke has the shortest orbital period of any major comet in our solar system. At its closest, it gets as close to the sun as does the planet Mercury, the planet closest to the sun. The orbit is stable, and the comet has probably been in the same orbit for thousands of years.

Was Comet Encke once part of a larger comet?

A recent theory is that Comet Encke was once part of a larger comet that broke up about 20,000 years ago. This event produced several small asteroids and the debris that now forms this meteor shower. And there are more. Scientists attribute at least three other meteor showers to Comet Encke. One stream of material might have delivered the object responsible for the Tunguska meteor event of 1908. This whole system is known as the Encke Complex.

Comet Encke, parent of the Taurid meteor showers. Image via NASA.

The next return of Comet Encke will be in July 2030.

What about Taurid fireballs?

Astronomers studying the Taurids found that Earth encounters a concentration of larger-than-normal debris at intervals of three or seven years resulting in a higher rate of fireballs.

The American Meteor Society said in 2022:

Taurid fireballs — visible in Earth’s skies in October and November — are often colorful. They often fragment as they streak slowly through the sky. In most years, only 1% of all Taurid meteors are fireballs. In exceptional years, when the Earth passes through a concentrated field of debris, the percentage can be as high as 7%. So visual observers and astrophotographers might see several fireballs each night instead of the normal rate of one every 20 hours.

And they were right! There were lots of fireball sightings in 2022.

The next predicted Taurid swarm is in 2032 and appears to be an exceptional year, as the moon will be new and Earth will pass very close to the center of the swarm.

Read more: Could Taurid fireballs – aka Halloween fireballs – bring a risk to Earth?

Why don’t the dates agree for Taurid meteors?

The story of the predicted peaks for the Taurids — which vary from place to place across the internet — is interesting. And a big reason is that astronomers are always learning new things.

For the most part, we count on the American Meteor Society and the Observer’s Handbook from the Royal Astronomical Society of Canada to provide us with the peak dates for the year’s major meteor showers.

So predicted peaks will vary. It’s nature! We don’t have it entirely pinned down.

View at EarthSky Community Photos. | Joel Weatherly in Edmonton, Alberta, Canada, created this composite from images captured on the morning of November 11, 2020. He wrote, “This is a composite image featuring Taurus and 4 meteors that I observed while out for the Northern Taurids meteor shower. The 2 brightest meteors left behind dust trails.” Thank you, Joel!

Bottom line: You might see a South Taurid meteor any time from about September 10 to November 20. That’s when Earth is plowing through the meteor stream – the stream of comet debris in space – that creates this meteor shower. The North Taurids stem from a nearby, but slightly different stream. They’re active from about October 20 to December 10. Both showers produce about five meteors per hour (10 total when they overlap).

**Predicted peak times and dates for meteor showers are from the American Meteor Society. Note that meteor shower peak times can vary.

Meteor showers: Tips for watching the show

Read more: Meteors in moonlight: 6 tips for watching

EarthSky’s meteor shower guide

The post Taurid meteors in 2026: All you need to know first appeared on EarthSky.

from EarthSky https://ift.tt/rhcbXuq

This active asteroid has grown a tail! What happened?

These 3 images show asteroid 6993 (1995 BJ4) on 3 separate dates this summer. Is this active asteroid better described as a comet, or did it grow a tail due to a collision? Image via the Zwicky Transient Facility/ NAU/ arXiv.

This active asteroid has grown a tail!

This summer, astronomers spotted something unusual about an asteroid in the main asteroid belt between Mars and Jupiter. The asteroid, named 6993 or 1995 BJ4, appeared to be shedding material and growing a tail, much like a comet. So how should we describe this strange object?

Astronomers are calling it an active asteroid … but it might become known as a comet. More specifically, it could join the small family of main-belt comets, or objects in the main asteroid belt with cometlike features.

However, that’s not the only explanation for this activity. The tail that’s showing up in these images could be the result of a collision among bodies in the main asteroid belt.

If the object does prove to be cometary in nature — with a tail created by sunlight vaporizing ice on its surface — 1995 BJ4 would be the largest-known main-belt comet. It’s about 7.5 miles (12 km) across. That makes it larger than 99% of asteroids. 1995 BJ4 also travels farther from the sun than most known active asteroids do.

Researchers with Northern Arizona University and other institutions discovered the activity using observations from the Zwicky Transient Facility. They published their study on October 22, 2026, on arXiv. It is not yet peer-reviewed.

EarthSky’s famous lunar calendar is now available. Beautiful blue and silver poster shows every day’s moon phase for 2027. Get yours now!

An asteroid with a tail

Most asteroids are static, rocky objects. The majority live in the main asteroid belt between Mars and Jupiter.

But some asteroids occasionally become active. They release dust and gas, creating a fuzzy cloud around the object or a visible tail. Astronomers call these objects active asteroids. And some are considered main-belt comets because they behave like comets while traveling among the asteroids. So far, astronomers have only found about 20 main-belt comets.

The discovery of 1995 BJ4 came through an automated system called the Solar System Notification Alert Processing System. Researchers trained a machine-learning model to recognize the fuzzy appearance of active asteroids. And on August 5, the model flagged an image of 1995 BJ4 with 99.9% confidence.

The team then checked earlier observations and found the tail had already been visible in images from the Zwicky Transient Facility dating back to June 25, 2026. The object showed a narrow, straight tail extending at least 32 arcseconds beyond its main body.

What is making the asteroid active?

The researchers considered several explanations for the activity.

One possibility that didn’t stand up to testing was the idea that the asteroid’s rotation is throwing material into space. But asteroid 1995 BJ4 rotates once every 3.9 hours. That’s not fast enough to achieve what the observations show.

But two other possibilities are still in the running.

One is that an impact with another space rock blasted dust from the asteroid’s surface. If so, the dust could gradually spread into space, causing the tail to fade over time. Because the asteroid appeared a tiny bit brighter in June and July than it was in August and September, that could point toward a collision with dust slowly dispersing.

But the possibility of sublimation — or sunlight warming buried ice — has not been ruled out. Sublimation is what causes material to vaporize on comets, carrying that material away from the surface. This process creates the familiar comas and tails of comets.

So both collision and sublimation are still possibilities, and the active asteroid’s true nature remains a secret, for now.

A possible record-setting main-belt comet

If it turns out that the tail is due to sublimation, it would make 1995 BJ4 the largest-known main-belt comet. Plus, it orbits farther from the sun than any known main-belt comet. Its closest approach to the sun, or perihelion, is about 2.85 times Earth’s distance from our star.

The active asteroid 6993 (1995 BJ4) orbits between Mars and Jupiter, in the outer edge of the main asteroid belt. Image via Tony Dunn.

Watch this asteroid in 2027

The researchers said continued observations will be important for figuring out what’s driving the activity.

1995 BJ4 will reach perihelion in January 2027. So if sunlight is vaporizing ice, astronomers might see its activity increase. But if the tail continues to fade, that would lend support to the impact explanation.

Scientists also hope to learn more about the asteroid’s composition. Its colors and reflectivity don’t fit neatly into existing classifications, leaving some uncertainty about what its surface contains.

Bottom line: Active asteroid 1995 BJ4 has grown a cometlike tail, leaving astronomers wondering what’s happening.

Source: Discovery of activity on Main Belt Asteroid 6993 (1995 BJ4)

Read more: Hera mission begins asteroid defense investigation: 1st closeup views!

Read more: Did comets seed life on Earth?

The post This active asteroid has grown a tail! What happened? first appeared on EarthSky.

from EarthSky https://ift.tt/86jHsBo

These 3 images show asteroid 6993 (1995 BJ4) on 3 separate dates this summer. Is this active asteroid better described as a comet, or did it grow a tail due to a collision? Image via the Zwicky Transient Facility/ NAU/ arXiv.

This active asteroid has grown a tail!

This summer, astronomers spotted something unusual about an asteroid in the main asteroid belt between Mars and Jupiter. The asteroid, named 6993 or 1995 BJ4, appeared to be shedding material and growing a tail, much like a comet. So how should we describe this strange object?

Astronomers are calling it an active asteroid … but it might become known as a comet. More specifically, it could join the small family of main-belt comets, or objects in the main asteroid belt with cometlike features.

However, that’s not the only explanation for this activity. The tail that’s showing up in these images could be the result of a collision among bodies in the main asteroid belt.

If the object does prove to be cometary in nature — with a tail created by sunlight vaporizing ice on its surface — 1995 BJ4 would be the largest-known main-belt comet. It’s about 7.5 miles (12 km) across. That makes it larger than 99% of asteroids. 1995 BJ4 also travels farther from the sun than most known active asteroids do.

Researchers with Northern Arizona University and other institutions discovered the activity using observations from the Zwicky Transient Facility. They published their study on October 22, 2026, on arXiv. It is not yet peer-reviewed.

EarthSky’s famous lunar calendar is now available. Beautiful blue and silver poster shows every day’s moon phase for 2027. Get yours now!

An asteroid with a tail

Most asteroids are static, rocky objects. The majority live in the main asteroid belt between Mars and Jupiter.

But some asteroids occasionally become active. They release dust and gas, creating a fuzzy cloud around the object or a visible tail. Astronomers call these objects active asteroids. And some are considered main-belt comets because they behave like comets while traveling among the asteroids. So far, astronomers have only found about 20 main-belt comets.

The discovery of 1995 BJ4 came through an automated system called the Solar System Notification Alert Processing System. Researchers trained a machine-learning model to recognize the fuzzy appearance of active asteroids. And on August 5, the model flagged an image of 1995 BJ4 with 99.9% confidence.

The team then checked earlier observations and found the tail had already been visible in images from the Zwicky Transient Facility dating back to June 25, 2026. The object showed a narrow, straight tail extending at least 32 arcseconds beyond its main body.

What is making the asteroid active?

The researchers considered several explanations for the activity.

One possibility that didn’t stand up to testing was the idea that the asteroid’s rotation is throwing material into space. But asteroid 1995 BJ4 rotates once every 3.9 hours. That’s not fast enough to achieve what the observations show.

But two other possibilities are still in the running.

One is that an impact with another space rock blasted dust from the asteroid’s surface. If so, the dust could gradually spread into space, causing the tail to fade over time. Because the asteroid appeared a tiny bit brighter in June and July than it was in August and September, that could point toward a collision with dust slowly dispersing.

But the possibility of sublimation — or sunlight warming buried ice — has not been ruled out. Sublimation is what causes material to vaporize on comets, carrying that material away from the surface. This process creates the familiar comas and tails of comets.

So both collision and sublimation are still possibilities, and the active asteroid’s true nature remains a secret, for now.

A possible record-setting main-belt comet

If it turns out that the tail is due to sublimation, it would make 1995 BJ4 the largest-known main-belt comet. Plus, it orbits farther from the sun than any known main-belt comet. Its closest approach to the sun, or perihelion, is about 2.85 times Earth’s distance from our star.

The active asteroid 6993 (1995 BJ4) orbits between Mars and Jupiter, in the outer edge of the main asteroid belt. Image via Tony Dunn.

Watch this asteroid in 2027

The researchers said continued observations will be important for figuring out what’s driving the activity.

1995 BJ4 will reach perihelion in January 2027. So if sunlight is vaporizing ice, astronomers might see its activity increase. But if the tail continues to fade, that would lend support to the impact explanation.

Scientists also hope to learn more about the asteroid’s composition. Its colors and reflectivity don’t fit neatly into existing classifications, leaving some uncertainty about what its surface contains.

Bottom line: Active asteroid 1995 BJ4 has grown a cometlike tail, leaving astronomers wondering what’s happening.

Source: Discovery of activity on Main Belt Asteroid 6993 (1995 BJ4)

Read more: Hera mission begins asteroid defense investigation: 1st closeup views!

Read more: Did comets seed life on Earth?

The post This active asteroid has grown a tail! What happened? first appeared on EarthSky.

from EarthSky https://ift.tt/86jHsBo

A runaway star moves fast in an unusual direction

This Hubble Space Telescope image shows a cloud in space where new stars are forming called 30 Doradus, aka the Tarantula Nebula. The enlarged inset shows a star that appears to have been kicked out of the nebula. In the inset, an arrow points to the runaway star and a dashed arrow to its presumed direction of motion. Image via NASA.

A runaway star moves faster and in a different direction

The sun and all of the Milky Way’s stars are moving in orbit around the center of our galaxy. It’s more or less orderly … but astronomers have identified some Milky Way stars that are moving faster than expected, and often in a direction that seems unusual. They use the term runaway star to describe these renegades.

Stars form in clouds of gas and dust. Multiple stars form from a single cloud. Therefore, many Milky Way stars move through space in loose associations, or more tightly bound open star clusters. By tracking the motions of a runaway star, astronomers can sometimes determine its original stellar companion. And, sometimes, they can work out what must have happened to kick the star on a different and much faster path to these stars.

Astronomers point to 2 possible reasons for a runaway star

The first scenario involves two binary star systems — two systems, each containing two stars — that pass close to each other. The encounter can disrupt both systems and eject one or more stars at relatively high speeds.

The second idea involves a supernova explosion in a multiple star system. These powerful explosions can propel associated stars that didn’t explode along new paths, at much-higher speeds.

GD 50 might be from the Pleiades

One runaway star is GD 50, a white dwarf star with a bit more mass than our sun, but smaller than the Earth. A dime as dense as GD 50 would weigh 2,600 pounds (~1,200 kilos) on Earth.

GD 50 lies within the bounds of the constellation Eridanus the River. And in 2009, astronomers who’d been studying this star found that it moves through space in the same direction and at the same speed as the Pleiades star cluster. The Pleiades is not far from Eridanus on the sky’s dome. GD 50 is also about the same age as stars in the Pleiades. Therefore, astronomers concluded that GD 50 was born in the Pleiades, then flung out, possibly after passing too close to another star.

Some other runaway stars

Further examples of runaway stars are AE Aurigae, 53 Arietis and Mu Columbae. They’re all moving away from each other at velocities of over 100 km/s (for comparison, our sun moves through the Milky Way at only about 20 km/s faster than the local average).

Tracing their motions backwards on the sky’s dome, astronomers can see that — about 2 million years ago — the paths of these stars intersected near the Orion Nebula. There is a great loop or bubble of gas called Barnard’s Loop surrounding Orion’s three prominent Belt stars. Barnard’s Loop may be the remnant of the supernova that launched these stars as runaway stars.

Explore runaway stars on Wikipedia

4 runaway stars plowing through regions of dense interstellar gas and creating bright bow waves and trailing tails of glowing gas. The stars in these NASA Hubble Space Telescope images are among 14 young runaway stars spotted by Hubble’s Advanced Camera for Surveys between October 2005 and July 2006. Image via Hubblesite/ Wikimedia Commons.

Bottom line: Runaway stars move differently from the general stream of stars in our Milky Way galaxy. The most compelling evidence suggests they were kicked out from their original star clusters by encounters between pairs of binary stars or by a supernova explosion.

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This Hubble Space Telescope image shows a cloud in space where new stars are forming called 30 Doradus, aka the Tarantula Nebula. The enlarged inset shows a star that appears to have been kicked out of the nebula. In the inset, an arrow points to the runaway star and a dashed arrow to its presumed direction of motion. Image via NASA.

A runaway star moves faster and in a different direction

The sun and all of the Milky Way’s stars are moving in orbit around the center of our galaxy. It’s more or less orderly … but astronomers have identified some Milky Way stars that are moving faster than expected, and often in a direction that seems unusual. They use the term runaway star to describe these renegades.

Stars form in clouds of gas and dust. Multiple stars form from a single cloud. Therefore, many Milky Way stars move through space in loose associations, or more tightly bound open star clusters. By tracking the motions of a runaway star, astronomers can sometimes determine its original stellar companion. And, sometimes, they can work out what must have happened to kick the star on a different and much faster path to these stars.

Astronomers point to 2 possible reasons for a runaway star

The first scenario involves two binary star systems — two systems, each containing two stars — that pass close to each other. The encounter can disrupt both systems and eject one or more stars at relatively high speeds.

The second idea involves a supernova explosion in a multiple star system. These powerful explosions can propel associated stars that didn’t explode along new paths, at much-higher speeds.

GD 50 might be from the Pleiades

One runaway star is GD 50, a white dwarf star with a bit more mass than our sun, but smaller than the Earth. A dime as dense as GD 50 would weigh 2,600 pounds (~1,200 kilos) on Earth.

GD 50 lies within the bounds of the constellation Eridanus the River. And in 2009, astronomers who’d been studying this star found that it moves through space in the same direction and at the same speed as the Pleiades star cluster. The Pleiades is not far from Eridanus on the sky’s dome. GD 50 is also about the same age as stars in the Pleiades. Therefore, astronomers concluded that GD 50 was born in the Pleiades, then flung out, possibly after passing too close to another star.

Some other runaway stars

Further examples of runaway stars are AE Aurigae, 53 Arietis and Mu Columbae. They’re all moving away from each other at velocities of over 100 km/s (for comparison, our sun moves through the Milky Way at only about 20 km/s faster than the local average).

Tracing their motions backwards on the sky’s dome, astronomers can see that — about 2 million years ago — the paths of these stars intersected near the Orion Nebula. There is a great loop or bubble of gas called Barnard’s Loop surrounding Orion’s three prominent Belt stars. Barnard’s Loop may be the remnant of the supernova that launched these stars as runaway stars.

Explore runaway stars on Wikipedia

4 runaway stars plowing through regions of dense interstellar gas and creating bright bow waves and trailing tails of glowing gas. The stars in these NASA Hubble Space Telescope images are among 14 young runaway stars spotted by Hubble’s Advanced Camera for Surveys between October 2005 and July 2006. Image via Hubblesite/ Wikimedia Commons.

Bottom line: Runaway stars move differently from the general stream of stars in our Milky Way galaxy. The most compelling evidence suggests they were kicked out from their original star clusters by encounters between pairs of binary stars or by a supernova explosion.

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Celebrate as Voyager 1 reaches 1 light-day from Earth! Here’s how

Artist’s concept of the redoubtable Voyager 1 spacecraft — most distant human-made object from Earth. Humanity launched it in 1977. It officially left our solar system in 2012, becoming the first to exit the heliosphere, or sphere of our sun’s influence. NASA said that at 12:16:07 a.m. CST on November 18, 2026, Voyager 1 will reach a distance of 1 light-day from Earth. Image via Caltech/ NASA-JPL.

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Voyager 1 to reach 1 light-day from Earth in November

Voyager 1 is the most distant human-made object from Earth. It launched into space on September 5, 1977, and visited Jupiter and Saturn before heading out of the solar system. It officially crossed out of our solar system, passing the heliopause – the sphere of the sun’s influence – back in 2012. And at 12:16:07 a.m. CST on November 18, 2026, NASA said that Voyager 1 will reach a major milestone: 1 light-day from Earth. That’s the distance it takes light to travel in 24 hours.

This historic milestone of 1 light-day is equal to about 16.1 billion miles (25.9 billion kilometers), or 173.14 astronomical units (AU). As of early October, the Voyager 1 spacecraft is about 15.98 billion miles (25.72 billion km) away from Earth. If we could peer at Voyager 1 through a telescope on Earth, the light we see left the spacecraft 23 hours, 52 minutes and 30 seconds ago. On November 18, it will breach the 24-hour mark.

And how long did it take Voyager 1 to travel 1 light-day? It took 49 years, 2 months, and 11 days to travel that distance from Earth. Keep on reading for how to celebrate this milestone.

Voyager 1 is now outside our solar system. On November 18, 2026, it will reach 1 light-day distant from Earth. Image via NASA/ JPL-Caltech.

Here’s how to celebrate!

To mark Voyager 1’s milestone of 1 light-day distant, NASA is organizing a worldwide Shine Bright celebration. After sunset on Tuesday, November 17, people can participate by pointing a flashlight, phone, glow stick or other light toward the sky and flashing the letters V-G-R for Voyager in Morse code.

So how do you spell V-G-R in Morse code? V is dot, dot, dot, dash. G is dash, dash, dot. And R is dot, dash, dot. If that’s too complicated, you can just NASA’s automated flasher here.

NASA hopes the worldwide light display will celebrate humanity’s remarkable achievement in sending a spacecraft farther into space than anything else they’ve ever built.

What about Voyager 2?

And where is Voyager 2? You might know that Voyager 2 actually launched a few weeks before its sister craft. But while Voyager 1 only visited Jupiter and Saturn, Voyager 2 took a Grand Tour, visiting all the gas giant planets: Jupiter, Saturn, Uranus and Neptune. So it’s not as far from Earth as Voyager 1.

But it’s not too far behind, relatively speaking. Voyager 2 is about 2 billion miles (3.2 billion km) closer to Earth than Voyager 1. It’s also moving a bit slower, so it can never catch up. Besides, Voyager 1 and 2 are not headed in the same direction anyway. Voyager 1 is headed “up” out of the solar plane, while Voyager 2 is headed “down.” Voyager 1 is moving toward the direction of the constellation Ophiuchus. And Voyager 2 is headed in the direction of the constellation Andromeda.

So when will Voyager 2 reach a distance of 1 light-day from us? NASA said not for nine more years, in November 2035.

Are the Voyager spacecraft still functioning?

Both Voyager spacecraft are still in communication with Earth, even though that process takes approximately a day for one-way messages. But most of the instruments on the Voyagers are no longer working. Over the years, NASA has turned off one system after another in order to save power. Just this year, in April 2026, NASA turned off the Low-Energy Charged Particle (LECP) instrument to save energy. This instrument was detecting electrons, ions and cosmic rays in the interstellar medium. But NASA could still turn it on at some point in the future for new measurements.

Both Voyager spacecraft carry a golden record that is etched with images and sounds to represent life on Earth. The golden records were a largely symbolic gesture meant to represent Earth in the wider universe and with the off-chance that an alien civilization would one day find them and learn something of their origins. As Carl Sagan said:

The spacecraft will be encountered and the record played only if there are advanced space-faring civilizations in interstellar space, but the launching of this ‘bottle’ into the cosmic ‘ocean’ says something very hopeful about life on this planet.

Bottom line: The Voyager 1 spacecraft — which launched from Earth in 1977 — will reach 1 light-day from Earth on November 18, 2026. It is the first human-made object to travel that far from Earth.

Via NASA

Read more: Why are the Voyager spacecraft getting closer to Earth now?

The post Celebrate as Voyager 1 reaches 1 light-day from Earth! Here’s how first appeared on EarthSky.

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Artist’s concept of the redoubtable Voyager 1 spacecraft — most distant human-made object from Earth. Humanity launched it in 1977. It officially left our solar system in 2012, becoming the first to exit the heliosphere, or sphere of our sun’s influence. NASA said that at 12:16:07 a.m. CST on November 18, 2026, Voyager 1 will reach a distance of 1 light-day from Earth. Image via Caltech/ NASA-JPL.

You deserve a daily dose of good news. For the latest in science and the night sky, subscribe to EarthSky’s free daily newsletter.

Voyager 1 to reach 1 light-day from Earth in November

Voyager 1 is the most distant human-made object from Earth. It launched into space on September 5, 1977, and visited Jupiter and Saturn before heading out of the solar system. It officially crossed out of our solar system, passing the heliopause – the sphere of the sun’s influence – back in 2012. And at 12:16:07 a.m. CST on November 18, 2026, NASA said that Voyager 1 will reach a major milestone: 1 light-day from Earth. That’s the distance it takes light to travel in 24 hours.

This historic milestone of 1 light-day is equal to about 16.1 billion miles (25.9 billion kilometers), or 173.14 astronomical units (AU). As of early October, the Voyager 1 spacecraft is about 15.98 billion miles (25.72 billion km) away from Earth. If we could peer at Voyager 1 through a telescope on Earth, the light we see left the spacecraft 23 hours, 52 minutes and 30 seconds ago. On November 18, it will breach the 24-hour mark.

And how long did it take Voyager 1 to travel 1 light-day? It took 49 years, 2 months, and 11 days to travel that distance from Earth. Keep on reading for how to celebrate this milestone.

Voyager 1 is now outside our solar system. On November 18, 2026, it will reach 1 light-day distant from Earth. Image via NASA/ JPL-Caltech.

Here’s how to celebrate!

To mark Voyager 1’s milestone of 1 light-day distant, NASA is organizing a worldwide Shine Bright celebration. After sunset on Tuesday, November 17, people can participate by pointing a flashlight, phone, glow stick or other light toward the sky and flashing the letters V-G-R for Voyager in Morse code.

So how do you spell V-G-R in Morse code? V is dot, dot, dot, dash. G is dash, dash, dot. And R is dot, dash, dot. If that’s too complicated, you can just NASA’s automated flasher here.

NASA hopes the worldwide light display will celebrate humanity’s remarkable achievement in sending a spacecraft farther into space than anything else they’ve ever built.

What about Voyager 2?

And where is Voyager 2? You might know that Voyager 2 actually launched a few weeks before its sister craft. But while Voyager 1 only visited Jupiter and Saturn, Voyager 2 took a Grand Tour, visiting all the gas giant planets: Jupiter, Saturn, Uranus and Neptune. So it’s not as far from Earth as Voyager 1.

But it’s not too far behind, relatively speaking. Voyager 2 is about 2 billion miles (3.2 billion km) closer to Earth than Voyager 1. It’s also moving a bit slower, so it can never catch up. Besides, Voyager 1 and 2 are not headed in the same direction anyway. Voyager 1 is headed “up” out of the solar plane, while Voyager 2 is headed “down.” Voyager 1 is moving toward the direction of the constellation Ophiuchus. And Voyager 2 is headed in the direction of the constellation Andromeda.

So when will Voyager 2 reach a distance of 1 light-day from us? NASA said not for nine more years, in November 2035.

Are the Voyager spacecraft still functioning?

Both Voyager spacecraft are still in communication with Earth, even though that process takes approximately a day for one-way messages. But most of the instruments on the Voyagers are no longer working. Over the years, NASA has turned off one system after another in order to save power. Just this year, in April 2026, NASA turned off the Low-Energy Charged Particle (LECP) instrument to save energy. This instrument was detecting electrons, ions and cosmic rays in the interstellar medium. But NASA could still turn it on at some point in the future for new measurements.

Both Voyager spacecraft carry a golden record that is etched with images and sounds to represent life on Earth. The golden records were a largely symbolic gesture meant to represent Earth in the wider universe and with the off-chance that an alien civilization would one day find them and learn something of their origins. As Carl Sagan said:

The spacecraft will be encountered and the record played only if there are advanced space-faring civilizations in interstellar space, but the launching of this ‘bottle’ into the cosmic ‘ocean’ says something very hopeful about life on this planet.

Bottom line: The Voyager 1 spacecraft — which launched from Earth in 1977 — will reach 1 light-day from Earth on November 18, 2026. It is the first human-made object to travel that far from Earth.

Via NASA

Read more: Why are the Voyager spacecraft getting closer to Earth now?

The post Celebrate as Voyager 1 reaches 1 light-day from Earth! Here’s how first appeared on EarthSky.

from EarthSky https://ift.tt/1Uc4NoX

Atmosphere of lava planet: ‘A cloudy, reflective sunscreen’

View larger. | Artist’s concept of super-Earth TOI-561 b. New observations by NASA’s James Webb Space Telescope show again that this distant world has a dense atmosphere. The atmosphere of lava planet TOI-561 b is highly reflective, suggesting clouds or haze. Image via CryoDragon Inc./ University of Birmingham.

• The super-Earth exoplanet TOI-561 b is hot and its surface is likely covered by molten lava. An atmosphere for this lava planet was an unexpected discovery.
• Additional observations using the Webb space telescope have re-confirmed the existence of this world’s dense atmosphere.
• The new observations also show that the atmosphere of TOI-561 b is highly reflective, with clouds or haze.

The 2027 lunar calendar from EarthSky is now available! See the moon’s phase for every day of the year. Get yours now!

Surprising atmosphere of lava planet TOI-561 b re-confirmed by Webb

Last December, scientists at the Carnegie Institution for Science in Washington, D.C. said rocky exoplanet TOI-561 b was a scorching hot super-Earth — a lava planet — with a thick atmosphere. It was a surprise, because scientists had thought it was too small and too close to its star to hold an atmosphere.

TOI-561 b is located some 280.5 light-years from Earth, in the direction of our constellation Sextans. It orbits extremely near its host star, completing a single orbit (a full “year”) in under 10.5 hours. Surface temperatures are estimated to be over 2,000 K (around 3,100°F / 1,700°C). At these extreme temperatures, rock melts, creating a global ocean of molten lava on its dayside.

Now we have an update on this fascinating world. Some of the same researchers that conducted the earlier study — led this time by the University of Montreal in Canada — said on October 27, 2026, that they used the James Webb Space Telescope to re-observe TOI-561 b. Their observations showed that there are clouds or haze in the atmosphere of this world. They also suggest it reflects much of the heat coming from the planet’s star back into space.

The researchers published their peer-reviewed findings in The Astronomical Journal on September 29, 2026.

And Evan Gough wrote about the latest observations for Universe Today on October 27, 2026.

A surprising atmosphere

TOI-561 b is what scientists call an ultra-short period (USP) planet. Even though it is a super-Earth, scientists thought that it was too small — and hot — to hold on to any atmosphere, due to being so close to its star.

But it seems that TOI-561 b does have an atmosphere, and a thick one at that. The paper states:

Ultrashort period (USP) rocky planets are expected to be depleted of any substantial gaseous envelope due to the intense irradiation they receive from their host star, making the recent detection of an atmosphere around TOI-561 b particularly surprising. That finding was based on the planet’s bulk density and dayside emission spectrum, but full-orbit phase-curve observations offer a more comprehensive way to constrain the presence and characteristics of a planet’s atmosphere.

View larger. | Emission spectrum of TOI-561 b from the James Webb Space Telescope. The data are consistent with an atmosphere rich in volatiles like water, oxygen and carbon dioxide. The model shown here assumes an atmosphere that is composed of 100% water vapor. Image via NASA/ ESA/ CSA/ Ralf Crawford (STScI); Science: Johanna Teske (Carnegie Science Earth and Planets Laboratory)/ Anjali Piette (University of Birmingham)/ Tim Lichtenberg (Groningen)/ Nicole Wallack (Carnegie Science Earth and Planets Laboratory).

The atmosphere of the lava planet is highly reflective

The researchers used Webb to observe TOI-561 b for 37 hours. That worked out to seeing three orbits of the planet, at 10.5 hours per orbit. That is good, because the more orbits that can be observed, the better for gathering data.

The previous observations had also shown that TOI-561 b has an atmosphere. How did the researchers determine this?

The dayside of the planet was a lot cooler than expected. That shouldn’t be the case if the planet had no atmosphere.

There were two possible explanations. Either heat was being reflected back into space or the atmosphere transported it to the nightside. But the results showed the nightside wasn’t warm enough. The researchers estimated that about 3/4 of the planet’s heat must be reflected into space. The paper states:

We conclude from the GCM simulations that heat redistribution alone cannot match the observed dayside fluxes or amplitude of the phase curve, and a high-albedo source (Ab = 0.6) indicative of clouds or haze.

Co-author Lisa Dang is the project lead at the University of Waterloo, Ontario, Canada. She explained:

We measured how the planet’s brightness and heat changed throughout its orbit. This technique, known as a phase curve, revealed that the planet reflects a significant amount of light from its star, and that heat is being redistributed around the planet instead of only on the sunlit side. Together, these point to the presence of an atmosphere.

Multiple kinds of clouds

The researchers said that clouds or haze are likely reflecting the heat. Silicon dioxide (SiO2) and magnesium metasilicate (MgSiO3) are two of the most likely compositions of the clouds. The paper states that:

… multiple possible cloud species can form on the dayside, including MgSiO3 and SiO2.

View larger. | Another artist’s concept of scorching hot TOI-561 b and its sunlike star. New observations by NASA’s James Webb Space Telescope show again there is a dense atmosphere on the planet. Image via NASA/ ESA/ CSA/ Ralf Crawford (STScI).

Challenging current theories

The findings are surprising, and they also challenge current theories about rocky ultra-short period planets. Dang said:

Our discovery challenges current theories. We would expect a heavily irradiated rocky planet like TOI-561 b to have lost its atmosphere billions of years ago. Instead, the evidence suggests it still has a significant atmosphere today.

And the paper states:

Atmospheric-escape theory suggests that strongly irradiated super-Earths should be devoid of any volatile envelopes. This is particularly astonishing given that the current JWST census of rocky exoplanets has been interpreted as suggestive of a population of bare-rock planets …

It’s also notable that TOI-561 b orbits a sun-like star. Most ultra-short period planets orbit red dwarfs. And red dwarfs are known for their bursts of deadly radiation. That radiation can strip the atmospheres off planets that are too close.

Yet TOI-561 b receives more radiation from its star than typical red dwarfs. And it still has an atmosphere! How is that possible?

Lisa Dang at the University of Waterloo is the project lead for the new study of TOI-561 b. Image via University of Waterloo.

How is the atmosphere of lava planet TOI-561 b possible?

The researchers aren’t sure how TOI-561 b has been able to keep its atmosphere. But they have ideas.

It might have started out with an even much thicker primordial atmosphere, perhaps as a sub-Neptune (larger than a super-Earth). The radiation might have indeed stripped away most or all of that atmosphere. So what’s left now is a secondary atmosphere.

It’s also possible that the planet originated much farther out from its star than where it is now. That would be when the star was still young. At that time, it emitted even more radiation.

When the planet migrated closer to the star, the star was already “calming down” and emitting less radiation. As a result, the remaining atmosphere was spared from destruction.

Or it could be that the answer lies in both scenarios.

But there’s another possibility, too. The planet “consumed” its original atmosphere. In other words, the atmosphere became trapped in the interior of the planet.

Co-author Anjali Piette, Assistant Professor in Astronomy at the University of Birmingham, said:

Our discovery challenges current theories. We would expect a heavily irradiated rocky planet like TOI-561 b to have lost its atmosphere billions of years ago. Instead, the evidence suggests it still has a significant atmosphere today. This raises major questions such as whether the planet started with an unusually large supply of gases or if the ocean of molten rock covering its surface acts as a planet-wide volcano that is constantly feeding its atmosphere.

View larger. | Artist’s concept of a lava planet. TOI-561 b orbits so close to its star that its surface is likely covered in molten lava. Image via ESO/ Wikimedia Commons.

Venus or Io?

The researchers want to know if TOI-561 b is more similar to Venus or Jupiter’s volcanic moon Io. Dang said:

The next big question we will seek to answer is whether TOI-561 b’s atmosphere resembles Venus or an extreme version of lo. Observing the planet at longer wavelengths with the JWST could give us insights and help explain how a planet this hot has held on to an atmosphere for billions of years.

The unexpected atmosphere of lava world TOI-561 b was a big surprise to astronomers. But it will also provide valuable data for studying other rocky super-Earth planets. How many other also have atmospheres, and what kind?

Bottom line: More recent observations of hot super-Earth TOI-561 b by the Webb space telescope show again that the lava planet’s surprising atmosphere does exist. And it’s very reflective.

Source: A Highly Reflective Atmosphere on the Lava World TOI-561b Revealed by JWST/NIRSpec Phase Curves

Via University of Birmingham

Via Universe Today

Read more: How do lava-world exoplanets keep their atmospheres?

Read more: Juno measures fiery Io’s subsurface temperature for 1st time

The post Atmosphere of lava planet: ‘A cloudy, reflective sunscreen’ first appeared on EarthSky.

from EarthSky https://ift.tt/IMLeNC7

View larger. | Artist’s concept of super-Earth TOI-561 b. New observations by NASA’s James Webb Space Telescope show again that this distant world has a dense atmosphere. The atmosphere of lava planet TOI-561 b is highly reflective, suggesting clouds or haze. Image via CryoDragon Inc./ University of Birmingham.

• The super-Earth exoplanet TOI-561 b is hot and its surface is likely covered by molten lava. An atmosphere for this lava planet was an unexpected discovery.
• Additional observations using the Webb space telescope have re-confirmed the existence of this world’s dense atmosphere.
• The new observations also show that the atmosphere of TOI-561 b is highly reflective, with clouds or haze.

The 2027 lunar calendar from EarthSky is now available! See the moon’s phase for every day of the year. Get yours now!

Surprising atmosphere of lava planet TOI-561 b re-confirmed by Webb

Last December, scientists at the Carnegie Institution for Science in Washington, D.C. said rocky exoplanet TOI-561 b was a scorching hot super-Earth — a lava planet — with a thick atmosphere. It was a surprise, because scientists had thought it was too small and too close to its star to hold an atmosphere.

TOI-561 b is located some 280.5 light-years from Earth, in the direction of our constellation Sextans. It orbits extremely near its host star, completing a single orbit (a full “year”) in under 10.5 hours. Surface temperatures are estimated to be over 2,000 K (around 3,100°F / 1,700°C). At these extreme temperatures, rock melts, creating a global ocean of molten lava on its dayside.

Now we have an update on this fascinating world. Some of the same researchers that conducted the earlier study — led this time by the University of Montreal in Canada — said on October 27, 2026, that they used the James Webb Space Telescope to re-observe TOI-561 b. Their observations showed that there are clouds or haze in the atmosphere of this world. They also suggest it reflects much of the heat coming from the planet’s star back into space.

The researchers published their peer-reviewed findings in The Astronomical Journal on September 29, 2026.

And Evan Gough wrote about the latest observations for Universe Today on October 27, 2026.

A surprising atmosphere

TOI-561 b is what scientists call an ultra-short period (USP) planet. Even though it is a super-Earth, scientists thought that it was too small — and hot — to hold on to any atmosphere, due to being so close to its star.

But it seems that TOI-561 b does have an atmosphere, and a thick one at that. The paper states:

Ultrashort period (USP) rocky planets are expected to be depleted of any substantial gaseous envelope due to the intense irradiation they receive from their host star, making the recent detection of an atmosphere around TOI-561 b particularly surprising. That finding was based on the planet’s bulk density and dayside emission spectrum, but full-orbit phase-curve observations offer a more comprehensive way to constrain the presence and characteristics of a planet’s atmosphere.

View larger. | Emission spectrum of TOI-561 b from the James Webb Space Telescope. The data are consistent with an atmosphere rich in volatiles like water, oxygen and carbon dioxide. The model shown here assumes an atmosphere that is composed of 100% water vapor. Image via NASA/ ESA/ CSA/ Ralf Crawford (STScI); Science: Johanna Teske (Carnegie Science Earth and Planets Laboratory)/ Anjali Piette (University of Birmingham)/ Tim Lichtenberg (Groningen)/ Nicole Wallack (Carnegie Science Earth and Planets Laboratory).

The atmosphere of the lava planet is highly reflective

The researchers used Webb to observe TOI-561 b for 37 hours. That worked out to seeing three orbits of the planet, at 10.5 hours per orbit. That is good, because the more orbits that can be observed, the better for gathering data.

The previous observations had also shown that TOI-561 b has an atmosphere. How did the researchers determine this?

The dayside of the planet was a lot cooler than expected. That shouldn’t be the case if the planet had no atmosphere.

There were two possible explanations. Either heat was being reflected back into space or the atmosphere transported it to the nightside. But the results showed the nightside wasn’t warm enough. The researchers estimated that about 3/4 of the planet’s heat must be reflected into space. The paper states:

We conclude from the GCM simulations that heat redistribution alone cannot match the observed dayside fluxes or amplitude of the phase curve, and a high-albedo source (Ab = 0.6) indicative of clouds or haze.

Co-author Lisa Dang is the project lead at the University of Waterloo, Ontario, Canada. She explained:

We measured how the planet’s brightness and heat changed throughout its orbit. This technique, known as a phase curve, revealed that the planet reflects a significant amount of light from its star, and that heat is being redistributed around the planet instead of only on the sunlit side. Together, these point to the presence of an atmosphere.

Multiple kinds of clouds

The researchers said that clouds or haze are likely reflecting the heat. Silicon dioxide (SiO2) and magnesium metasilicate (MgSiO3) are two of the most likely compositions of the clouds. The paper states that:

… multiple possible cloud species can form on the dayside, including MgSiO3 and SiO2.

View larger. | Another artist’s concept of scorching hot TOI-561 b and its sunlike star. New observations by NASA’s James Webb Space Telescope show again there is a dense atmosphere on the planet. Image via NASA/ ESA/ CSA/ Ralf Crawford (STScI).

Challenging current theories

The findings are surprising, and they also challenge current theories about rocky ultra-short period planets. Dang said:

Our discovery challenges current theories. We would expect a heavily irradiated rocky planet like TOI-561 b to have lost its atmosphere billions of years ago. Instead, the evidence suggests it still has a significant atmosphere today.

And the paper states:

Atmospheric-escape theory suggests that strongly irradiated super-Earths should be devoid of any volatile envelopes. This is particularly astonishing given that the current JWST census of rocky exoplanets has been interpreted as suggestive of a population of bare-rock planets …

It’s also notable that TOI-561 b orbits a sun-like star. Most ultra-short period planets orbit red dwarfs. And red dwarfs are known for their bursts of deadly radiation. That radiation can strip the atmospheres off planets that are too close.

Yet TOI-561 b receives more radiation from its star than typical red dwarfs. And it still has an atmosphere! How is that possible?

Lisa Dang at the University of Waterloo is the project lead for the new study of TOI-561 b. Image via University of Waterloo.

How is the atmosphere of lava planet TOI-561 b possible?

The researchers aren’t sure how TOI-561 b has been able to keep its atmosphere. But they have ideas.

It might have started out with an even much thicker primordial atmosphere, perhaps as a sub-Neptune (larger than a super-Earth). The radiation might have indeed stripped away most or all of that atmosphere. So what’s left now is a secondary atmosphere.

It’s also possible that the planet originated much farther out from its star than where it is now. That would be when the star was still young. At that time, it emitted even more radiation.

When the planet migrated closer to the star, the star was already “calming down” and emitting less radiation. As a result, the remaining atmosphere was spared from destruction.

Or it could be that the answer lies in both scenarios.

But there’s another possibility, too. The planet “consumed” its original atmosphere. In other words, the atmosphere became trapped in the interior of the planet.

Co-author Anjali Piette, Assistant Professor in Astronomy at the University of Birmingham, said:

Our discovery challenges current theories. We would expect a heavily irradiated rocky planet like TOI-561 b to have lost its atmosphere billions of years ago. Instead, the evidence suggests it still has a significant atmosphere today. This raises major questions such as whether the planet started with an unusually large supply of gases or if the ocean of molten rock covering its surface acts as a planet-wide volcano that is constantly feeding its atmosphere.

View larger. | Artist’s concept of a lava planet. TOI-561 b orbits so close to its star that its surface is likely covered in molten lava. Image via ESO/ Wikimedia Commons.

Venus or Io?

The researchers want to know if TOI-561 b is more similar to Venus or Jupiter’s volcanic moon Io. Dang said:

The next big question we will seek to answer is whether TOI-561 b’s atmosphere resembles Venus or an extreme version of lo. Observing the planet at longer wavelengths with the JWST could give us insights and help explain how a planet this hot has held on to an atmosphere for billions of years.

The unexpected atmosphere of lava world TOI-561 b was a big surprise to astronomers. But it will also provide valuable data for studying other rocky super-Earth planets. How many other also have atmospheres, and what kind?

Bottom line: More recent observations of hot super-Earth TOI-561 b by the Webb space telescope show again that the lava planet’s surprising atmosphere does exist. And it’s very reflective.

Source: A Highly Reflective Atmosphere on the Lava World TOI-561b Revealed by JWST/NIRSpec Phase Curves

Via University of Birmingham

Via Universe Today

Read more: How do lava-world exoplanets keep their atmospheres?

Read more: Juno measures fiery Io’s subsurface temperature for 1st time

The post Atmosphere of lava planet: ‘A cloudy, reflective sunscreen’ first appeared on EarthSky.

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See the Summer Triangle in the northern autumn sky

The Summer Triangle is a famous asterism, consisting of 3 bright stars. These stars are overhead in summer. But you can also easily see them through the northern autumn. Chart via EarthSky.

The Summer Triangle in autumn

The Summer Triangle isn’t a constellation. It’s an asterism, an obvious pattern or group of stars with a popular name. The Summer Triangle consists of three bright stars in three separate constellations.

The Summer Triangle is the signature star formation in the Northern Hemisphere’s summer sky. However, as the September equinox comes and goes – and as the weeks of autumn begin to slide by – you’ll continue to notice this famous trio of stars.

You’ll find the Summer Triangle in November and December. Look for it tonight in the early evening. Look west!

In early November, the Summer Triangle is high in the western sky around mid-evening. Image via WyoAstro All-sky camera.

The 3 stars of the Summer Triangle

The brightest of the three stars is Vega is in the constellation Lyra the Harp. It’s the 5th-brightest star in our night sky. You’ll recognize Vega for its blue-white color. This star is located 25 light-years away.

Next in brightness is the star Altair is in Aquila the Eagle. Its only 16.7 light-years away. You’ll recognize Altair becuase it’s flanked closely by two fainter stars.

Deneb — in Cygnus the Swan — is the faintest of the Summer Triangle stars. But it has good reason to be faintest to our eye, because Deneb is one of the most distant stars we see with the unaided eye. It’s a luminous supergiant star, located roughly 1,400 to 2,600 light–years from Earth.

When is it visible in the evening sky

In the month of June – around the June solstice – the Summer Triangle pops out in the east as darkness falls and shines all night long. But now – after sunset in November – the Summer Triangle appears high in the western evening sky. As evening deepens, the Summer Triangle descends westward, with all three of its stars staying above the horizon until mid-to-late evening.

Altair – the Summer Triangle’s southernmost star – will set around 10 to 11 p.m. in November at mid-northern latitudes. Notice where you see the Summer Triangle at a given time this evening. The Summer Triangle will return to this same place in the sky some four minutes earlier with each passing day, or two hours earlier with each passing month.

Bottom line: Look westward this evening for the three brilliant stars of the Summer Triangle: Vega, Deneb and Altair.

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The Summer Triangle is a famous asterism, consisting of 3 bright stars. These stars are overhead in summer. But you can also easily see them through the northern autumn. Chart via EarthSky.

The Summer Triangle in autumn

The Summer Triangle isn’t a constellation. It’s an asterism, an obvious pattern or group of stars with a popular name. The Summer Triangle consists of three bright stars in three separate constellations.

The Summer Triangle is the signature star formation in the Northern Hemisphere’s summer sky. However, as the September equinox comes and goes – and as the weeks of autumn begin to slide by – you’ll continue to notice this famous trio of stars.

You’ll find the Summer Triangle in November and December. Look for it tonight in the early evening. Look west!

In early November, the Summer Triangle is high in the western sky around mid-evening. Image via WyoAstro All-sky camera.

The 3 stars of the Summer Triangle

The brightest of the three stars is Vega is in the constellation Lyra the Harp. It’s the 5th-brightest star in our night sky. You’ll recognize Vega for its blue-white color. This star is located 25 light-years away.

Next in brightness is the star Altair is in Aquila the Eagle. Its only 16.7 light-years away. You’ll recognize Altair becuase it’s flanked closely by two fainter stars.

Deneb — in Cygnus the Swan — is the faintest of the Summer Triangle stars. But it has good reason to be faintest to our eye, because Deneb is one of the most distant stars we see with the unaided eye. It’s a luminous supergiant star, located roughly 1,400 to 2,600 light–years from Earth.

When is it visible in the evening sky

In the month of June – around the June solstice – the Summer Triangle pops out in the east as darkness falls and shines all night long. But now – after sunset in November – the Summer Triangle appears high in the western evening sky. As evening deepens, the Summer Triangle descends westward, with all three of its stars staying above the horizon until mid-to-late evening.

Altair – the Summer Triangle’s southernmost star – will set around 10 to 11 p.m. in November at mid-northern latitudes. Notice where you see the Summer Triangle at a given time this evening. The Summer Triangle will return to this same place in the sky some four minutes earlier with each passing day, or two hours earlier with each passing month.

Bottom line: Look westward this evening for the three brilliant stars of the Summer Triangle: Vega, Deneb and Altair.

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

The post See the Summer Triangle in the northern autumn sky first appeared on EarthSky.

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Backward world? Rubin finds a retrograde object past Neptune

Rubin Observatory has discovered a retrograde object, currently labeled R631. It orbits the sun beyond the orbit of the 8th planet, Neptune, at a steep inclination. Simulation via Tony Dunn.

Rubin finds retrograde object past Neptune

The new Rubin Observatory in Chile has found an object beyond Neptune that follows a retrograde orbit. Most other other planets, moons and asteroids orbit our sun in a more or less flat plane. They generally move in the same direction, counterclockwise as seen from earthly north.

This object’s orbit is highly inclined, slicing through at a severe angle.

When we hear the word retrograde, we tend to think of an object moving backward in its orbit, against the direction of most planets, and many asteroids and moons. But in astronomy, retrograde has a more precise meaning. Any object whose orbit is tilted more than 90 degrees relative to the plane of the solar system is considered to be in retrograde motion.

This newly discovered object, currently designated R631 in the Rubin data, has an orbital inclination of 142 degrees. So its orbit is tilted beyond perpendicular, and it is moving in the opposite direction from most planets.

EarthSky’s famous lunar calendar is now available. Beautiful blue and silver poster shows every day’s moon phase for 2027. Get yours now!

What sort of object is R631?

The designation R631 is only temporary. The object will soon get an official designation from the Minor Planet Center. Astronomers and citizens alike who monitor Rubin’s alert stream noticed this object, which has appeared over four months in the data. Rubin’s observations of the retrograde object are from December 2025 through March 2026.

R631 is located 32 astronomical units (AU) from our sun. That’s 30 times the Earth-sun distance. And it would place the object just beyond the orbit of Neptune, which is 30 AU from the sun. The object R631 will reach its closest point to the sun, or perihelion, on October 31, 2047, at a distance of 24 AU.

If this orbit is correct, it will take object R631 some 547.84 Earth-years to make one full orbit of the sun.

Physicist and astronomer Marshall Eubanks said on Minor Planet Mailing List that the object could be 62 miles (100 km) in diameter. He said it might be akin to giant Comet Bernardinelli–Bernstein (comet C/2014 UN271), the largest known Oort cloud comet.

If R631 is cometary in nature, it might show some activity (such as outgassing) around the time of its 2047 perihelion. In June 2025, we reported that Comet Bernardinelli–Bernstein has been belching jets from a distance of 16.6 AU from our sun.

Why does R631 orbit in retrograde motion?

Why do objects in our solar system tend to orbit the sun in the same direction? And why might this object be orbiting differently from other objects?

Our solar system is thought to have been formed from a spinning cloud of gas and dust in space. The central concentration of mass pulled itself inward through gravity to form the sun. The rest of the dust and gas went on to clump together and eventually form planets, with crumbs left over as objects such as asteroids, moons and comets.

So there are several ways R631 might have developed a retrograde orbit. It might have been born in another solar system — flung out of its that system, perhaps when the system brushed too close to ours — and ultimately was pulled into the sun’s gravity well.

Alternatively, it might have begun life in our solar system, in an ordinary prograde orbit, like Earth’s. It might then have passed too close to a large object, say Jupiter or a passing star, which flung it into a retrograde path.

Sam Deen, an amateur astronomer who finds lost objects such as asteroids and comets in archival data, said the retrograde object is likely from the Kuiper belt and became destabilized when it passed too close to Neptune sometime in the past billion years.

Is R631 related to the Kreutz sungrazers?

This is not the first object discovered with a retrograde orbit. In fact, there was another famous object that had a 142-degree inclination: the Great Comet of 1882.

This comet was bright. It might have been the brightest natural object in the sky in recorded history. It was visible in daylight, reaching what some say was a magnitude of -17. That’s in contrast to our sun, which has a magnitude of -26. The Great Comet of 1882 came so close to our sun that it broke into fragments. Its highly inclined orbit matched that of the Kreutz sungrazer family of comets, a group of comets that follow remarkably similar orbits, bringing them extremely close to the sun at their nearest approach.

Comet Ikeya-Seki was another Kreutz sungrazer that had an inclination of about 142 degrees. It had a spectacular encounter with the sun in October 1965. Although it survived its extremely close passage, its nucleus broke apart into several pieces. Those fragments gradually faded as they traveled away from the sun.

Scientists think the Kreutz sungrazer comets are all remnants of a single, massive ancient comet that fragmented hundreds or thousands of years ago.

If you’re curious — like I was — if R631 could be from that same object, Tony Dunn ran a simulation of the Kreutz sungrazers versus R631 and the rest of the solar system. His simulation makes it clear that R631 is unrelated.

The retrograde object R631 has a 142 degree inclination from the plane of our solar system. The Kreutz sungrazing comets also have a 142 degree inclination, but they take starkly different paths from R631. R631 is in green, and the Kreutz sungrazers are in white. Simulation via Tony Dunn.

Bottom line: The Rubin Observatory in Chile has discovered a retrograde object in our solar system. It circles the sun in a highly inclined orbit beyond Neptune.

Via Minor Planet Mailing List

The post Backward world? Rubin finds a retrograde object past Neptune first appeared on EarthSky.

from EarthSky https://ift.tt/uGkot8l

Rubin Observatory has discovered a retrograde object, currently labeled R631. It orbits the sun beyond the orbit of the 8th planet, Neptune, at a steep inclination. Simulation via Tony Dunn.

Rubin finds retrograde object past Neptune

The new Rubin Observatory in Chile has found an object beyond Neptune that follows a retrograde orbit. Most other other planets, moons and asteroids orbit our sun in a more or less flat plane. They generally move in the same direction, counterclockwise as seen from earthly north.

This object’s orbit is highly inclined, slicing through at a severe angle.

When we hear the word retrograde, we tend to think of an object moving backward in its orbit, against the direction of most planets, and many asteroids and moons. But in astronomy, retrograde has a more precise meaning. Any object whose orbit is tilted more than 90 degrees relative to the plane of the solar system is considered to be in retrograde motion.

This newly discovered object, currently designated R631 in the Rubin data, has an orbital inclination of 142 degrees. So its orbit is tilted beyond perpendicular, and it is moving in the opposite direction from most planets.

EarthSky’s famous lunar calendar is now available. Beautiful blue and silver poster shows every day’s moon phase for 2027. Get yours now!

What sort of object is R631?

The designation R631 is only temporary. The object will soon get an official designation from the Minor Planet Center. Astronomers and citizens alike who monitor Rubin’s alert stream noticed this object, which has appeared over four months in the data. Rubin’s observations of the retrograde object are from December 2025 through March 2026.

R631 is located 32 astronomical units (AU) from our sun. That’s 30 times the Earth-sun distance. And it would place the object just beyond the orbit of Neptune, which is 30 AU from the sun. The object R631 will reach its closest point to the sun, or perihelion, on October 31, 2047, at a distance of 24 AU.

If this orbit is correct, it will take object R631 some 547.84 Earth-years to make one full orbit of the sun.

Physicist and astronomer Marshall Eubanks said on Minor Planet Mailing List that the object could be 62 miles (100 km) in diameter. He said it might be akin to giant Comet Bernardinelli–Bernstein (comet C/2014 UN271), the largest known Oort cloud comet.

If R631 is cometary in nature, it might show some activity (such as outgassing) around the time of its 2047 perihelion. In June 2025, we reported that Comet Bernardinelli–Bernstein has been belching jets from a distance of 16.6 AU from our sun.

Why does R631 orbit in retrograde motion?

Why do objects in our solar system tend to orbit the sun in the same direction? And why might this object be orbiting differently from other objects?

Our solar system is thought to have been formed from a spinning cloud of gas and dust in space. The central concentration of mass pulled itself inward through gravity to form the sun. The rest of the dust and gas went on to clump together and eventually form planets, with crumbs left over as objects such as asteroids, moons and comets.

So there are several ways R631 might have developed a retrograde orbit. It might have been born in another solar system — flung out of its that system, perhaps when the system brushed too close to ours — and ultimately was pulled into the sun’s gravity well.

Alternatively, it might have begun life in our solar system, in an ordinary prograde orbit, like Earth’s. It might then have passed too close to a large object, say Jupiter or a passing star, which flung it into a retrograde path.

Sam Deen, an amateur astronomer who finds lost objects such as asteroids and comets in archival data, said the retrograde object is likely from the Kuiper belt and became destabilized when it passed too close to Neptune sometime in the past billion years.

Is R631 related to the Kreutz sungrazers?

This is not the first object discovered with a retrograde orbit. In fact, there was another famous object that had a 142-degree inclination: the Great Comet of 1882.

This comet was bright. It might have been the brightest natural object in the sky in recorded history. It was visible in daylight, reaching what some say was a magnitude of -17. That’s in contrast to our sun, which has a magnitude of -26. The Great Comet of 1882 came so close to our sun that it broke into fragments. Its highly inclined orbit matched that of the Kreutz sungrazer family of comets, a group of comets that follow remarkably similar orbits, bringing them extremely close to the sun at their nearest approach.

Comet Ikeya-Seki was another Kreutz sungrazer that had an inclination of about 142 degrees. It had a spectacular encounter with the sun in October 1965. Although it survived its extremely close passage, its nucleus broke apart into several pieces. Those fragments gradually faded as they traveled away from the sun.

Scientists think the Kreutz sungrazer comets are all remnants of a single, massive ancient comet that fragmented hundreds or thousands of years ago.

If you’re curious — like I was — if R631 could be from that same object, Tony Dunn ran a simulation of the Kreutz sungrazers versus R631 and the rest of the solar system. His simulation makes it clear that R631 is unrelated.

The retrograde object R631 has a 142 degree inclination from the plane of our solar system. The Kreutz sungrazing comets also have a 142 degree inclination, but they take starkly different paths from R631. R631 is in green, and the Kreutz sungrazers are in white. Simulation via Tony Dunn.

Bottom line: The Rubin Observatory in Chile has discovered a retrograde object in our solar system. It circles the sun in a highly inclined orbit beyond Neptune.

Via Minor Planet Mailing List

The post Backward world? Rubin finds a retrograde object past Neptune first appeared on EarthSky.

from EarthSky https://ift.tt/uGkot8l