Giant mega-Earth is 23 times more massive than Earth

View larger. | Artist’s concept of a giant mega-Earth. The newly discovered mega-Earth GJ 523b is 23.5 times the mass of Earth and 2.5 times its size. Image via Pablo Carlos Budassi/ Wikimedia Commons.

• Astronomers have confirmed an unusual planet called GJ 523b. It belongs to a rare group of worlds known as mega-Earths.
• The planet is only about 2.5 times as wide as Earth but has more than 23 times its mass. That makes it unusually dense.
• Scientists don’t understand how it formed this way. A planet this massive would normally be expected to have a thick atmosphere of hydrogen and helium.

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

Giant mega-Earth is 23 times Earth’s mass

On July 23, 2026, astronomers at the University of Wisconsin–Madison announced the confirmation of GJ 523b, an unusually dense mega-Earth first detected in data from NASA’s TESS telescope.

Rocky exoplanets called super-Earths are quite common in our galaxy. These worlds are larger and more massive than Earth, but smaller than Neptune. But now astronomers have found an even more massive planets called  mega-Earths. Fewer mega-Earths have been discovered so far than super-Earths, but they do exist. This newest one – GJ 523b – might be the best example known so far. It is a whopping 23 times as massive as Earth.

GJ 523b is 2.5 times the diameter of Earth. Some super-Earths can be that large, but the extreme mass is unusual. And the planet is estimated to be only 170 million years old. That’s in contrast to Earth’s age of 4.54 billion years. So the GJ 523 system is much younger than our own solar system. The planet orbits a orange dwarf star.

Thomas Beatty at University of Wisconsin-Madison said:

People have been using the phrase ‘Mega-Earth’ for more than a decade, but we’ve never had a planet that let us say concretely what one is. GJ 523b finally does. What is also striking is that nailing down the definition of a Mega-Earth isn’t something us astronomers can really do by ourselves: We need geologists who understand how iron and rock behave at pressures no laboratory on Earth can reach, and atmospheric scientists who can tell us how much of what we measured is rock at all.

The new paper is still undergoing peer-review but was first published on the preprint server arXiv on March 25, 2026.

TESS makes a surprising discovery

Astronomers first used NASA’s TESS space telescope first detected GJ 523b as it passed in front of its star, causing a tiny dip in the star’s brightness. These transits allowed astronomers to estimate the planet’s size.

Lead author Max Kroft at University of Wisconsin-Madison said:

There’s this periodic dipping of the star’s light. We think that’s a planet passing in front of the star and transiting. It’s blocking some of the light from the star, and the star gets dimmer.

We picked out this planet based on what we thought its size and temperature were. A bigger planet makes a bigger dip, so we get an idea of the size, and based on how often that dip happens, we get the distance of its orbit and we can use that to estimate the temperature of the exoplanet.

The researchers then used the NEID spectrograph and data on the WIYN 3.5-meter telescope to determine it’s mass. High-resolution imaging from Gemini North and Palomarto were used to further study GJ 523b. They found some surprises. It was more massive than most rocky planets of its size; 23.5 times more massive than Earth and 2.5 times the diameter of Earth, or 60% the size of Neptune. As Kroft noted, this was an unexpected finding:

This isn’t what we expected at all. Dense planets like this aren’t uncommon, but they’re usually small rocky planets similar to Earth or Mercury. This planet is 2.5 times bigger than the Earth.

Max Kroft at University of Wisconsin-Madison led the new study about GJ 523b. Image via University of Wisconsin-Madison.

How did GJ 523b form this way?

So how did GJ 523b end up being so extremely dense and massive? Why didn’t the planet develop a massive hydrogen atmosphere?

In the words of Kroft, the discovery was:

a real curveball.

During planet formation, worlds with cores around 10 to 20 times Earth’s mass are generally expected to pull in thick atmospheres of hydrogen and helium. GJ 523b is massive enough for this to happen, yet it appears to contain very little gas.

The study found that ordinary heating from the star probably could not remove enough gas. Giant impacts, an extremely close passage by the star or forming without much gas are possible explanations.

Kroft also notes that the planet would still have been hot from its formation. Too hot to hold onto its atmosphere. Krofft explained:

It kind of blows away. A planet can’t hold on to its atmosphere if it’s really hot, and so you could be left with this big glob of rock made by these two planets with very little atmosphere.

The planet’s orbit offers another clue.

The researchers estimate that it is tilted by at least 71 degrees relative to the rotation of its star. This unusual alignment suggests that GJ 523b might have migrated from elsewhere in the system or experienced a turbulent event early in its history.

More planets like GJ 523b

The researchers are hopeful that astronomers will find more planets like GJ 523b. There are over 6,000 confirmed exoplanets already found, and thousands more candidates. Kroft said:

It’s hard to infer things about planet formation in general from a sample size of one. We’re not going to get to 10,000 of these over-dense planets, but if we can get to 20 or 30, maybe some trends might pop out, where maybe the heaviest ones have shorter orbital periods, or they tend not to have companion planets.

Bottom line: Astronomers discover mega-Earth, GJ 523b, has 23.5 times Earth’s mass but only 2.5 times its radius. Its extreme density, apparent lack of a thick gas atmosphere and highly tilted orbit challenge standard ideas about how massive planets form.

Source: GJ 523b is a Massive, 170 Myr-old Mega-Earth, Likely on a Polar Orbit

Via University of Wisconsin-Madison

Via Phys.org

Read more: Kepler-10 star system has a mega-Earth!

Read more: Exoplanet art lets you visualize alien worlds

The post Giant mega-Earth is 23 times more massive than Earth first appeared on EarthSky.

from EarthSky https://ift.tt/MWrkqcR

View larger. | Artist’s concept of a giant mega-Earth. The newly discovered mega-Earth GJ 523b is 23.5 times the mass of Earth and 2.5 times its size. Image via Pablo Carlos Budassi/ Wikimedia Commons.

• Astronomers have confirmed an unusual planet called GJ 523b. It belongs to a rare group of worlds known as mega-Earths.
• The planet is only about 2.5 times as wide as Earth but has more than 23 times its mass. That makes it unusually dense.
• Scientists don’t understand how it formed this way. A planet this massive would normally be expected to have a thick atmosphere of hydrogen and helium.

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

Giant mega-Earth is 23 times Earth’s mass

On July 23, 2026, astronomers at the University of Wisconsin–Madison announced the confirmation of GJ 523b, an unusually dense mega-Earth first detected in data from NASA’s TESS telescope.

Rocky exoplanets called super-Earths are quite common in our galaxy. These worlds are larger and more massive than Earth, but smaller than Neptune. But now astronomers have found an even more massive planets called  mega-Earths. Fewer mega-Earths have been discovered so far than super-Earths, but they do exist. This newest one – GJ 523b – might be the best example known so far. It is a whopping 23 times as massive as Earth.

GJ 523b is 2.5 times the diameter of Earth. Some super-Earths can be that large, but the extreme mass is unusual. And the planet is estimated to be only 170 million years old. That’s in contrast to Earth’s age of 4.54 billion years. So the GJ 523 system is much younger than our own solar system. The planet orbits a orange dwarf star.

Thomas Beatty at University of Wisconsin-Madison said:

People have been using the phrase ‘Mega-Earth’ for more than a decade, but we’ve never had a planet that let us say concretely what one is. GJ 523b finally does. What is also striking is that nailing down the definition of a Mega-Earth isn’t something us astronomers can really do by ourselves: We need geologists who understand how iron and rock behave at pressures no laboratory on Earth can reach, and atmospheric scientists who can tell us how much of what we measured is rock at all.

The new paper is still undergoing peer-review but was first published on the preprint server arXiv on March 25, 2026.

TESS makes a surprising discovery

Astronomers first used NASA’s TESS space telescope first detected GJ 523b as it passed in front of its star, causing a tiny dip in the star’s brightness. These transits allowed astronomers to estimate the planet’s size.

Lead author Max Kroft at University of Wisconsin-Madison said:

There’s this periodic dipping of the star’s light. We think that’s a planet passing in front of the star and transiting. It’s blocking some of the light from the star, and the star gets dimmer.

We picked out this planet based on what we thought its size and temperature were. A bigger planet makes a bigger dip, so we get an idea of the size, and based on how often that dip happens, we get the distance of its orbit and we can use that to estimate the temperature of the exoplanet.

The researchers then used the NEID spectrograph and data on the WIYN 3.5-meter telescope to determine it’s mass. High-resolution imaging from Gemini North and Palomarto were used to further study GJ 523b. They found some surprises. It was more massive than most rocky planets of its size; 23.5 times more massive than Earth and 2.5 times the diameter of Earth, or 60% the size of Neptune. As Kroft noted, this was an unexpected finding:

This isn’t what we expected at all. Dense planets like this aren’t uncommon, but they’re usually small rocky planets similar to Earth or Mercury. This planet is 2.5 times bigger than the Earth.

Max Kroft at University of Wisconsin-Madison led the new study about GJ 523b. Image via University of Wisconsin-Madison.

How did GJ 523b form this way?

So how did GJ 523b end up being so extremely dense and massive? Why didn’t the planet develop a massive hydrogen atmosphere?

In the words of Kroft, the discovery was:

a real curveball.

During planet formation, worlds with cores around 10 to 20 times Earth’s mass are generally expected to pull in thick atmospheres of hydrogen and helium. GJ 523b is massive enough for this to happen, yet it appears to contain very little gas.

The study found that ordinary heating from the star probably could not remove enough gas. Giant impacts, an extremely close passage by the star or forming without much gas are possible explanations.

Kroft also notes that the planet would still have been hot from its formation. Too hot to hold onto its atmosphere. Krofft explained:

It kind of blows away. A planet can’t hold on to its atmosphere if it’s really hot, and so you could be left with this big glob of rock made by these two planets with very little atmosphere.

The planet’s orbit offers another clue.

The researchers estimate that it is tilted by at least 71 degrees relative to the rotation of its star. This unusual alignment suggests that GJ 523b might have migrated from elsewhere in the system or experienced a turbulent event early in its history.

More planets like GJ 523b

The researchers are hopeful that astronomers will find more planets like GJ 523b. There are over 6,000 confirmed exoplanets already found, and thousands more candidates. Kroft said:

It’s hard to infer things about planet formation in general from a sample size of one. We’re not going to get to 10,000 of these over-dense planets, but if we can get to 20 or 30, maybe some trends might pop out, where maybe the heaviest ones have shorter orbital periods, or they tend not to have companion planets.

Bottom line: Astronomers discover mega-Earth, GJ 523b, has 23.5 times Earth’s mass but only 2.5 times its radius. Its extreme density, apparent lack of a thick gas atmosphere and highly tilted orbit challenge standard ideas about how massive planets form.

Source: GJ 523b is a Massive, 170 Myr-old Mega-Earth, Likely on a Polar Orbit

Via University of Wisconsin-Madison

Via Phys.org

Read more: Kepler-10 star system has a mega-Earth!

Read more: Exoplanet art lets you visualize alien worlds

The post Giant mega-Earth is 23 times more massive than Earth first appeared on EarthSky.

from EarthSky https://ift.tt/MWrkqcR

Will fall migration bring a billion bird night?

This is the BirdCast fall migration forecast for the evening of September 4, 2026. BirdCast predicts around 219 million birds crossing the United States, with the highest concentrations in the locations with the lightest colors. Millions of birds regularly cross the U.S. in fall as they head south. And sometimes up to a billion birds a night can take flight. Map generated at 6 UTC September 6. Image via Van Doren (Illinois) and Horton (Purdue) Cornell Lab of Ornithology. See most recent map here.

Will we see a billion birds during fall migration?

It’s peak fall migration season for birds! While the numbers of birds crossing the U.S. is usually in the millions during September and October, we can sometimes see a billion bird night. That happened last year, on September 25, 2025, when BirdCast tracked more than 1.2 billion birds heading south after sunset. That was the most BirdCast had ever tracked in one night since it began its project in 2018. How do they track the birds? They use:

the same weather radar technology behind daily forecasts to track migrating birds.

On that night, about 10% of North America’s birds were in flight at the same time. And there’s something you can do in the fall to help them make their journey southward.

Lights out for birds during fall migration!

Every day you can check the BirdCast.info website to get an idea of what regions will see the highest number of birds passing each night. So when your area is especially active, turn off your exterior lights and encourage your neighbors to do the same. Artificial lights disorient birds, changing their behavior and sometimes leading to their deaths.

BirdCast.info says:

Light pollution attracts and disorients migrating birds, confusing and exhausting them as well as making them vulnerable to collisions with buildings.

So here’s what you can do:

• Turn off non-essential lights from 11 p.m. until 6 a.m. during critical migration periods
• Turn off or dim lobby and atrium lights
• Be sure outside lights are aimed down and well shielded
• Turn off or dim interior home lighting, or draw blinds to prevent light escaping
• Turn off decorative landscape lighting
• Install motion sensors on outside lights to minimize use
• Turn off lights before leaving the home or office
• Prevent daylight collisions with bird-friendly products for windows

Read more: Want to save millions of migratory birds? Turn off your outdoor lights in spring and fall

Migration maps

The maps from BirdCast.info depict migratory patterns over the years. As the website explains:

Bird migration forecasts show predicted nocturnal migration 3 hours after local sunset and are updated every 6 hours. These forecasts come from models trained on the last 23 years of bird movements in the atmosphere as detected by the US NEXRAD weather surveillance radar network.

You can get the next three nights’ worth of maps at the site. And besides the prediction maps, you can also find live bird migration maps. They’ll give you an idea of where birds are active right now. Birds are most active after dark. And if you don’t want to keep checking back at the website to see when birds are active in your area, you can sign up for alerts.

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

Sites to help you see and protect birds

Tracking and research tools:

• BirdCast
  Migration forecasts, live radar-based migration maps and alerts you can use to know when migration is happening in your area.
• Motus Wildlife Tracking System
  A global collaboration using small tracking tags (for birds, bats, insects) and receiving stations to map how animals move across landscapes.
• Audubon’s Bird Migration Explorer
  Interactive maps and data showing annual migration routes for hundreds of species across North America.
• National Zoo: Migratory Birds Tracking Map
  Shows real tracking data (from tagged birds) on real maps.
• Journey North
  Citizen science and seasonal tracking of migrating species (birds, butterflies, etc.).
• Canadian Migration Monitoring Network (CMMN)
  Long-term monitoring of migration trends in Canada, via many observatories.
• PixCams Live Bird Migration Station
  A hybrid setup (optical + thermal + acoustic) giving real-time monitoring of nocturnal migrations.
• MigrantWatch (India)
  A citizen science effort to log migratory bird sightings in India.
• eBird India

A nationwide citizen-science platform where birdwatchers record their sightings to build an open database tracking bird distribution, abundance and migration patterns across India year-round.

Some initiatives for protecting migrating birds:

• Audubon Lights Out Program
  Encourages turning off/excluding unnecessary lighting during migration seasons to reduce bird collisions.
• Lights Out Heartland
  A regional campaign in the U.S. Midwest focused on reducing light pollution during key migration windows.
• FLAP Canada (Fatal Light Awareness Program)
  Works on reducing collisions, raising awareness, and tracking collisions especially in Canada.
• City & Local Lights Out Programs
  Many cities have local versions that you can join or replicate in your area.

Bottom line: Will we see a billion bird night during fall migration this year? And get tips on how you can help birds by turning off exterior lights.

Read more: Fall hummingbird migration in progress across North America

The post Will fall migration bring a billion bird night? first appeared on EarthSky.

from EarthSky https://ift.tt/8pMIB4E

This is the BirdCast fall migration forecast for the evening of September 4, 2026. BirdCast predicts around 219 million birds crossing the United States, with the highest concentrations in the locations with the lightest colors. Millions of birds regularly cross the U.S. in fall as they head south. And sometimes up to a billion birds a night can take flight. Map generated at 6 UTC September 6. Image via Van Doren (Illinois) and Horton (Purdue) Cornell Lab of Ornithology. See most recent map here.

Will we see a billion birds during fall migration?

It’s peak fall migration season for birds! While the numbers of birds crossing the U.S. is usually in the millions during September and October, we can sometimes see a billion bird night. That happened last year, on September 25, 2025, when BirdCast tracked more than 1.2 billion birds heading south after sunset. That was the most BirdCast had ever tracked in one night since it began its project in 2018. How do they track the birds? They use:

the same weather radar technology behind daily forecasts to track migrating birds.

On that night, about 10% of North America’s birds were in flight at the same time. And there’s something you can do in the fall to help them make their journey southward.

Lights out for birds during fall migration!

Every day you can check the BirdCast.info website to get an idea of what regions will see the highest number of birds passing each night. So when your area is especially active, turn off your exterior lights and encourage your neighbors to do the same. Artificial lights disorient birds, changing their behavior and sometimes leading to their deaths.

BirdCast.info says:

Light pollution attracts and disorients migrating birds, confusing and exhausting them as well as making them vulnerable to collisions with buildings.

So here’s what you can do:

• Turn off non-essential lights from 11 p.m. until 6 a.m. during critical migration periods
• Turn off or dim lobby and atrium lights
• Be sure outside lights are aimed down and well shielded
• Turn off or dim interior home lighting, or draw blinds to prevent light escaping
• Turn off decorative landscape lighting
• Install motion sensors on outside lights to minimize use
• Turn off lights before leaving the home or office
• Prevent daylight collisions with bird-friendly products for windows

Read more: Want to save millions of migratory birds? Turn off your outdoor lights in spring and fall

Migration maps

The maps from BirdCast.info depict migratory patterns over the years. As the website explains:

Bird migration forecasts show predicted nocturnal migration 3 hours after local sunset and are updated every 6 hours. These forecasts come from models trained on the last 23 years of bird movements in the atmosphere as detected by the US NEXRAD weather surveillance radar network.

You can get the next three nights’ worth of maps at the site. And besides the prediction maps, you can also find live bird migration maps. They’ll give you an idea of where birds are active right now. Birds are most active after dark. And if you don’t want to keep checking back at the website to see when birds are active in your area, you can sign up for alerts.

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

Sites to help you see and protect birds

Tracking and research tools:

• BirdCast
  Migration forecasts, live radar-based migration maps and alerts you can use to know when migration is happening in your area.
• Motus Wildlife Tracking System
  A global collaboration using small tracking tags (for birds, bats, insects) and receiving stations to map how animals move across landscapes.
• Audubon’s Bird Migration Explorer
  Interactive maps and data showing annual migration routes for hundreds of species across North America.
• National Zoo: Migratory Birds Tracking Map
  Shows real tracking data (from tagged birds) on real maps.
• Journey North
  Citizen science and seasonal tracking of migrating species (birds, butterflies, etc.).
• Canadian Migration Monitoring Network (CMMN)
  Long-term monitoring of migration trends in Canada, via many observatories.
• PixCams Live Bird Migration Station
  A hybrid setup (optical + thermal + acoustic) giving real-time monitoring of nocturnal migrations.
• MigrantWatch (India)
  A citizen science effort to log migratory bird sightings in India.
• eBird India

A nationwide citizen-science platform where birdwatchers record their sightings to build an open database tracking bird distribution, abundance and migration patterns across India year-round.

Some initiatives for protecting migrating birds:

• Audubon Lights Out Program
  Encourages turning off/excluding unnecessary lighting during migration seasons to reduce bird collisions.
• Lights Out Heartland
  A regional campaign in the U.S. Midwest focused on reducing light pollution during key migration windows.
• FLAP Canada (Fatal Light Awareness Program)
  Works on reducing collisions, raising awareness, and tracking collisions especially in Canada.
• City & Local Lights Out Programs
  Many cities have local versions that you can join or replicate in your area.

Bottom line: Will we see a billion bird night during fall migration this year? And get tips on how you can help birds by turning off exterior lights.

Read more: Fall hummingbird migration in progress across North America

The post Will fall migration bring a billion bird night? first appeared on EarthSky.

from EarthSky https://ift.tt/8pMIB4E

Fomalhaut is the Loneliest Star once again

Saturn and Fomalhaut are the brightest two objects showing from this all-sky camera taken from inside an observatory in Wyoming. They are also below the Great Square of Pegasus. Image via WyoAstro allsky camera. Used with permission.

Fomalhaut, bright and lonely

Fomalhaut, aka Alpha Piscis Austrinus, carries the nickname the Loneliest Star. That’s because Fomalhaut is the only bright star in a wide stretch of sky. From the Northern Hemisphere in autumn, Fomalhaut arcs across the southern sky in solitary splendor … usually. Over the past few years, it was befriended in the sky by golden Saturn. But in autumn 2026, Saturn is starting to leave Fomalhaut alone once again.

Saturn takes a leisurely 30 years to complete one orbit of the sun. That means it moves very slowly against the background stars. And so, it spent several years making its way past Fomalhaut. Now, in 2026, Saturn and Fomalhaut are no longer particularly close. They’re separated by some 43 degrees (about 4 fists at arm’s length) on the sky’s dome.

But they’re still the 2 brightest objects in that sparse patch of sky. To make sure you don’t get these objects confused, know that Saturn is the brighter of the two. Plus it will shine with a steady light, while Fomalhaut might be twinkling. And Saturn will be located more to the east on the sky’s dome.

That’s also true from the Southern Hemisphere. But in the Southern Hemisphere, you’ll need to face north and look higher up in the sky to see Fomalhaut and Saturn in your season of spring.

Fomalhaut is a young star with dusty debris disks around it. Does it have planets? The answer to that is one of astronomy’s most fascinating stories! Read more below.

How to see it

Fomalhaut is the 18th brightest star in the night sky. It’s part of the faint constellation Piscis Austrinus the Southern Fish. In a dark sky, you’ll see a half-circle of faint stars of which bright Fomalhaut is a part. This star pattern marks the open mouth of the Southern Fish.

In early September, Fomalhaut is opposite the sun. So, it shines in the sky all night. It reaches its culmination – its highest point in the sky – around local midnight in mid-September.

Fomalhaut culminates at different times on different dates. Here are just a few approximate times and dates of culmination:

July 15: 4:30 a.m. daylight saving time (DST)
August 15: 2:30 a.m. DST
September 15: 12:30 a.m. DST
October 15: 10:30 p.m. DST
November 15: 8:30 p.m. DST
December 15: 5:30 p.m. standard time

Piscis Austrinus the Southern Fish is notable for its one bright star, Fomalhaut. When you look toward Fomalhaut, you are looking out our Milky Way galaxy’s south window and into intergalactic space. By the way, the rest of the stars making up Piscis Austrinus are faint and difficult to see unless you have a dark sky. Chart via EarthSky.

The view from different hemispheres

From the Northern Hemisphere, you can see Fomalhaut from as far north as 60 degrees latitude (southern Alaska, central Canada, northern Europe), where it just skims the southern horizon. From the Southern Hemisphere, Fomalhaut appears much higher in the sky. You can use one of several stargazing smartphone apps, some that are free, to help you find it. Or visit Stellarium-Web.org, the free online planetarium, and enter your location and time.

The star Fomalhaut as seen by an Earth-based telescope on November 13, 2008. Image via NASA/ ESA/ Digitized Sky Survey 2/ Davide De Martin (ESA/Hubble)/ ESA.

Rings of dust and gas

Fomalhaut is a hot white star about 25 light-years away. It’s almost twice the mass and size of our sun but radiates over 16 times the sun’s energy. Fomalhaut has a companion star less than a light-year away from it. The companion is an orange dwarf star, about 70% the mass of our sun. A third member of the Fomalhaut star system was announced in 2013, a small reddish star about 2.5 light-years from Fomalhaut. From Earth, we see the third star located in the constellation Aquarius instead of Piscis Austrinus.

Fomalhaut itself is a young star, just 440 million years old. That’s in contrast to 4 1/2 billion years for our sun. Fomalhaut is surrounded by a striking system of debris disks, revealed in detail by Hubble, ALMA, and the Webb space telescope. It has a broad, cold outer belt – similar to our Kuiper Belt – but also inner, nested belts and gaps whose sharp edges and offsets suggest they are being shaped by unseen planets.

A planet for Fomalhaut?

A study published in 2008 generated a lot of excitement when Hubble Space Telescope images – taken in 2004, 2006 and 2008 – showed a faint moving dot near Fomalhaut. This object was called Fomalhaut b. It was thought to be located just a few astronomical units (AU) from the star (so at a distance not unlike Earth’s). It was immediately hailed as the first exoplanet seen in visible light!

But later observations complicated the story. The object faded and eventually vanished from view, leading many astronomers to suggest it wasn’t a planet after all, but instead a dust cloud from a collision of icy bodies.

The dust ring around Fomalhaut, however, is sharply edged and offset from the star, features that usually hint at the presence of planets shaping the debris.

Fomalhaut b probably not a planet

So the current picture (as of 2026):

• Fomalhaut b is probably not a planet.
• But indirect evidence strongly suggests that planets must be there, sculpting the debris disk, even though none have yet been directly confirmed.

New Webb observations (especially with its MIRI instrument) show that Fomalhaut has multiple nested belts of dust and gaps, some interior to the main outer debris belt. There’s at least one intermediate belt (between the star and the outer belt) that could be “shepherded” by a planet. The belts are misaligned relative to each other.

On the left, a Hubble Space Telescope image showing Fomalhaut’s debris disk. The star itself has been blocked so its brightness doesn’t drown out the view of the faint ring. The small box shows the object once thought to be a planet (but no more). On the right is a simulation, based on observations, of how the object appeared from 2004 to 2014. The object is now thought to be the result of a collision in the disk. Image via NASA.

Fomalhaut in history and mythology

The name Fomalhaut derives from the Arabic Fum al Hut, meaning Mouth of the Fish.

In the sky visible from the Northern Hemisphere, the constellation Aquarius the Water Bearer resides above Fomalhaut’s constellation Piscis Austrinus. You can see a zigzag line of stars from Aquarius to Piscis Austrinus. In sky lore, this line of stars represents water from the Jar of the Water Bearer, trickling into the open Mouth of the Fish.

1 of the 4 guardians

According to Richard Hinckley Allen, Fomalhaut was one of the four guardians of the heavens to the ancient Persians, in 3,000 BCE, called by them Hastorang. (The other guardians were Aldebaran in Taurus, Antares in Scorpius, and Regulus in Leo.) Around 2,500 BCE, Fomalhaut helped mark the location of the winter solstice, meaning that it helped to define the location in the sky where the sun crossed the meridian at noon on the first day of winter. Also Allen also says that in 500 BCE, people worshipped Fomalhaut at the temple of Demeter in Eleusis, in ancient Greece.

View larger. | Here’s an 1822 illustration of Aquarius the Water Carrier, the constellation above Fomalhaut’s constellation, Piscis Austrinus the Southern Fish. This illustration is from Alexander Jamieson’s Celestial Atlas. In the illustration, water from the Water Jar of Aquarius is going into the Mouth of the Southern Fish. if it’s dark where you are, you can easily see a zigzag line of stars extending from Aquarius to the star Fomalhaut … the same starry zigzag that inspired the idea of water in the minds of the early constellation-namers. Image via Wikimedia.

Bottom line: Fomalhaut is known as the Loneliest Star because it shines brightly in an otherwise dim patch of sky. In recent years, it has been joined by Saturn. But in 2026, Saturn is starting to pull away. Fomalhaut is of special interest to astronomers because of debris rings around it that are possibly the beginnings of a planetary system.

Read more: Fomalhaut has 3 nested belts around the star

The post Fomalhaut is the Loneliest Star once again first appeared on EarthSky.

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Saturn and Fomalhaut are the brightest two objects showing from this all-sky camera taken from inside an observatory in Wyoming. They are also below the Great Square of Pegasus. Image via WyoAstro allsky camera. Used with permission.

Fomalhaut, bright and lonely

Fomalhaut, aka Alpha Piscis Austrinus, carries the nickname the Loneliest Star. That’s because Fomalhaut is the only bright star in a wide stretch of sky. From the Northern Hemisphere in autumn, Fomalhaut arcs across the southern sky in solitary splendor … usually. Over the past few years, it was befriended in the sky by golden Saturn. But in autumn 2026, Saturn is starting to leave Fomalhaut alone once again.

Saturn takes a leisurely 30 years to complete one orbit of the sun. That means it moves very slowly against the background stars. And so, it spent several years making its way past Fomalhaut. Now, in 2026, Saturn and Fomalhaut are no longer particularly close. They’re separated by some 43 degrees (about 4 fists at arm’s length) on the sky’s dome.

But they’re still the 2 brightest objects in that sparse patch of sky. To make sure you don’t get these objects confused, know that Saturn is the brighter of the two. Plus it will shine with a steady light, while Fomalhaut might be twinkling. And Saturn will be located more to the east on the sky’s dome.

That’s also true from the Southern Hemisphere. But in the Southern Hemisphere, you’ll need to face north and look higher up in the sky to see Fomalhaut and Saturn in your season of spring.

Fomalhaut is a young star with dusty debris disks around it. Does it have planets? The answer to that is one of astronomy’s most fascinating stories! Read more below.

How to see it

Fomalhaut is the 18th brightest star in the night sky. It’s part of the faint constellation Piscis Austrinus the Southern Fish. In a dark sky, you’ll see a half-circle of faint stars of which bright Fomalhaut is a part. This star pattern marks the open mouth of the Southern Fish.

In early September, Fomalhaut is opposite the sun. So, it shines in the sky all night. It reaches its culmination – its highest point in the sky – around local midnight in mid-September.

Fomalhaut culminates at different times on different dates. Here are just a few approximate times and dates of culmination:

July 15: 4:30 a.m. daylight saving time (DST)
August 15: 2:30 a.m. DST
September 15: 12:30 a.m. DST
October 15: 10:30 p.m. DST
November 15: 8:30 p.m. DST
December 15: 5:30 p.m. standard time

Piscis Austrinus the Southern Fish is notable for its one bright star, Fomalhaut. When you look toward Fomalhaut, you are looking out our Milky Way galaxy’s south window and into intergalactic space. By the way, the rest of the stars making up Piscis Austrinus are faint and difficult to see unless you have a dark sky. Chart via EarthSky.

The view from different hemispheres

From the Northern Hemisphere, you can see Fomalhaut from as far north as 60 degrees latitude (southern Alaska, central Canada, northern Europe), where it just skims the southern horizon. From the Southern Hemisphere, Fomalhaut appears much higher in the sky. You can use one of several stargazing smartphone apps, some that are free, to help you find it. Or visit Stellarium-Web.org, the free online planetarium, and enter your location and time.

The star Fomalhaut as seen by an Earth-based telescope on November 13, 2008. Image via NASA/ ESA/ Digitized Sky Survey 2/ Davide De Martin (ESA/Hubble)/ ESA.

Rings of dust and gas

Fomalhaut is a hot white star about 25 light-years away. It’s almost twice the mass and size of our sun but radiates over 16 times the sun’s energy. Fomalhaut has a companion star less than a light-year away from it. The companion is an orange dwarf star, about 70% the mass of our sun. A third member of the Fomalhaut star system was announced in 2013, a small reddish star about 2.5 light-years from Fomalhaut. From Earth, we see the third star located in the constellation Aquarius instead of Piscis Austrinus.

Fomalhaut itself is a young star, just 440 million years old. That’s in contrast to 4 1/2 billion years for our sun. Fomalhaut is surrounded by a striking system of debris disks, revealed in detail by Hubble, ALMA, and the Webb space telescope. It has a broad, cold outer belt – similar to our Kuiper Belt – but also inner, nested belts and gaps whose sharp edges and offsets suggest they are being shaped by unseen planets.

A planet for Fomalhaut?

A study published in 2008 generated a lot of excitement when Hubble Space Telescope images – taken in 2004, 2006 and 2008 – showed a faint moving dot near Fomalhaut. This object was called Fomalhaut b. It was thought to be located just a few astronomical units (AU) from the star (so at a distance not unlike Earth’s). It was immediately hailed as the first exoplanet seen in visible light!

But later observations complicated the story. The object faded and eventually vanished from view, leading many astronomers to suggest it wasn’t a planet after all, but instead a dust cloud from a collision of icy bodies.

The dust ring around Fomalhaut, however, is sharply edged and offset from the star, features that usually hint at the presence of planets shaping the debris.

Fomalhaut b probably not a planet

So the current picture (as of 2026):

• Fomalhaut b is probably not a planet.
• But indirect evidence strongly suggests that planets must be there, sculpting the debris disk, even though none have yet been directly confirmed.

New Webb observations (especially with its MIRI instrument) show that Fomalhaut has multiple nested belts of dust and gaps, some interior to the main outer debris belt. There’s at least one intermediate belt (between the star and the outer belt) that could be “shepherded” by a planet. The belts are misaligned relative to each other.

On the left, a Hubble Space Telescope image showing Fomalhaut’s debris disk. The star itself has been blocked so its brightness doesn’t drown out the view of the faint ring. The small box shows the object once thought to be a planet (but no more). On the right is a simulation, based on observations, of how the object appeared from 2004 to 2014. The object is now thought to be the result of a collision in the disk. Image via NASA.

Fomalhaut in history and mythology

The name Fomalhaut derives from the Arabic Fum al Hut, meaning Mouth of the Fish.

In the sky visible from the Northern Hemisphere, the constellation Aquarius the Water Bearer resides above Fomalhaut’s constellation Piscis Austrinus. You can see a zigzag line of stars from Aquarius to Piscis Austrinus. In sky lore, this line of stars represents water from the Jar of the Water Bearer, trickling into the open Mouth of the Fish.

1 of the 4 guardians

According to Richard Hinckley Allen, Fomalhaut was one of the four guardians of the heavens to the ancient Persians, in 3,000 BCE, called by them Hastorang. (The other guardians were Aldebaran in Taurus, Antares in Scorpius, and Regulus in Leo.) Around 2,500 BCE, Fomalhaut helped mark the location of the winter solstice, meaning that it helped to define the location in the sky where the sun crossed the meridian at noon on the first day of winter. Also Allen also says that in 500 BCE, people worshipped Fomalhaut at the temple of Demeter in Eleusis, in ancient Greece.

View larger. | Here’s an 1822 illustration of Aquarius the Water Carrier, the constellation above Fomalhaut’s constellation, Piscis Austrinus the Southern Fish. This illustration is from Alexander Jamieson’s Celestial Atlas. In the illustration, water from the Water Jar of Aquarius is going into the Mouth of the Southern Fish. if it’s dark where you are, you can easily see a zigzag line of stars extending from Aquarius to the star Fomalhaut … the same starry zigzag that inspired the idea of water in the minds of the early constellation-namers. Image via Wikimedia.

Bottom line: Fomalhaut is known as the Loneliest Star because it shines brightly in an otherwise dim patch of sky. In recent years, it has been joined by Saturn. But in 2026, Saturn is starting to pull away. Fomalhaut is of special interest to astronomers because of debris rings around it that are possibly the beginnings of a planetary system.

Read more: Fomalhaut has 3 nested belts around the star

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Sapphire: September birthstone comes in many colors

The September birthstone is the sapphire. Although it comes in many colors, the traditional blue sapphire is always a popular choice and sometimes used in engagement rings. Image via Marcy Curran.

September birthstone

September’s birthstone, the sapphire, is a relative of July’s birthstone, the ruby. That’s because both are forms of the mineral corundum, a crystalline form of aluminum oxide. But the red corundum is ruby. And all other gem-quality forms of corundum are sapphires.

All corundum, including sapphire, has a hardness of 9 on the Mohs scale. In fact, sapphires are second in hardness only to diamonds.

The September birthstone is sapphire. Although it’s traditionally thought of as blue, it comes in many colors such as this pink sapphire ring. Image via Charles Sharp/ Wikipedia.

Source of sapphires

Typically, sapphires appear as blue stones. They range from very pale blue to deep indigo. In fact, the exact shade depends on how much titanium and iron lies within the crystal structure. The most valued shade of blue is the medium-deep cornflower blue. However, sapphires also occur in other natural colors and tints – colorless, gray, yellow, pale pink, orange, green, violet and brown – called fancy sapphires. Different kinds of impurities within the crystal cause the various gemstone colors. For example, yellow sapphires get their color from ferric iron, and colorless gems have no contaminants.

Primarily, the biggest source of sapphires world-wide is Australia, especially New South Wales and Queensland. They are found in alluvial deposits of weathered basalt. Australian sapphires typically are blue stones with a dark and inky appearance. On the other hand, Kashmir, in India, used to be a well-known source of the cornflower-blue stones. And in the United States, a major source is the Yogo Gulch Mine in Montana. It mostly yields small stones for industrial use.

Sapphire lore about the September birthstone

The word sapphire has its roots in ancient languages: from the Latin sapphirus (meaning blue) and from the Greek word sappheiros for the island of Sappherine in the Arabian Sea, the name being derived from the Arabic word safir. Sappherine was the source for sapphire in ancient Grecian times. Ancient Persians called sapphire the “Celestial Stone.” It was the gem of Apollo, Greek God of prophecy. Worshipers visiting his shrine in Delphi to seek his help wore sapphires. Ancient Etruscans used sapphires as far back as the 7th century BCE.

Besides being the September birthstone, the sapphire represented the purity of the soul. Before and during the Middle Ages, priests wore it as protection from impure thoughts and temptations of the flesh. Medieval kings of Europe valued these stones for rings and brooches, believing that it protected them from harm and envy. Warriors presented their young wives with sapphire necklaces so they would remain faithful. A common belief was that the stone’s color would darken if worn by an adulterer or adulteress, or by an unworthy person.

Some believed sapphires protected people from snakes. People believed that by placing poisonous reptiles and spiders in a jar containing the stone, the creatures would immediately die. The French of the 13th century believed that sapphire transformed stupidity to wisdom, and irritability to good temper.

Of course, probably the best-known color of sapphire is blue. Image via gemrockauctions.com. Used with permission.

Some famous sapphires

One of the most famous sapphires rests on the Imperial State Crown worn by Queen Victoria in 1838. It resides with the British Crown Jewels in the Tower of London. In fact, this gem once belonged to Edward the Confessor. He wore the stone on a ring during his coronation in 1042, and it became known as St. Edward’s Sapphire.

The Logan Sapphire Brooch, the second largest sapphire known (at 422.99 carats), is on display at the National Museum of Natural History in Washington, D.C. Image via Andrew Bossi/ Wikipedia.

Bottom line: The September birthstone is the sapphire. It is generally known as a blue gemstone, but it comes in many colors.

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

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

The post Sapphire: September birthstone comes in many colors first appeared on EarthSky.

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The September birthstone is the sapphire. Although it comes in many colors, the traditional blue sapphire is always a popular choice and sometimes used in engagement rings. Image via Marcy Curran.

September birthstone

September’s birthstone, the sapphire, is a relative of July’s birthstone, the ruby. That’s because both are forms of the mineral corundum, a crystalline form of aluminum oxide. But the red corundum is ruby. And all other gem-quality forms of corundum are sapphires.

All corundum, including sapphire, has a hardness of 9 on the Mohs scale. In fact, sapphires are second in hardness only to diamonds.

The September birthstone is sapphire. Although it’s traditionally thought of as blue, it comes in many colors such as this pink sapphire ring. Image via Charles Sharp/ Wikipedia.

Source of sapphires

Typically, sapphires appear as blue stones. They range from very pale blue to deep indigo. In fact, the exact shade depends on how much titanium and iron lies within the crystal structure. The most valued shade of blue is the medium-deep cornflower blue. However, sapphires also occur in other natural colors and tints – colorless, gray, yellow, pale pink, orange, green, violet and brown – called fancy sapphires. Different kinds of impurities within the crystal cause the various gemstone colors. For example, yellow sapphires get their color from ferric iron, and colorless gems have no contaminants.

Primarily, the biggest source of sapphires world-wide is Australia, especially New South Wales and Queensland. They are found in alluvial deposits of weathered basalt. Australian sapphires typically are blue stones with a dark and inky appearance. On the other hand, Kashmir, in India, used to be a well-known source of the cornflower-blue stones. And in the United States, a major source is the Yogo Gulch Mine in Montana. It mostly yields small stones for industrial use.

Sapphire lore about the September birthstone

The word sapphire has its roots in ancient languages: from the Latin sapphirus (meaning blue) and from the Greek word sappheiros for the island of Sappherine in the Arabian Sea, the name being derived from the Arabic word safir. Sappherine was the source for sapphire in ancient Grecian times. Ancient Persians called sapphire the “Celestial Stone.” It was the gem of Apollo, Greek God of prophecy. Worshipers visiting his shrine in Delphi to seek his help wore sapphires. Ancient Etruscans used sapphires as far back as the 7th century BCE.

Besides being the September birthstone, the sapphire represented the purity of the soul. Before and during the Middle Ages, priests wore it as protection from impure thoughts and temptations of the flesh. Medieval kings of Europe valued these stones for rings and brooches, believing that it protected them from harm and envy. Warriors presented their young wives with sapphire necklaces so they would remain faithful. A common belief was that the stone’s color would darken if worn by an adulterer or adulteress, or by an unworthy person.

Some believed sapphires protected people from snakes. People believed that by placing poisonous reptiles and spiders in a jar containing the stone, the creatures would immediately die. The French of the 13th century believed that sapphire transformed stupidity to wisdom, and irritability to good temper.

Of course, probably the best-known color of sapphire is blue. Image via gemrockauctions.com. Used with permission.

Some famous sapphires

One of the most famous sapphires rests on the Imperial State Crown worn by Queen Victoria in 1838. It resides with the British Crown Jewels in the Tower of London. In fact, this gem once belonged to Edward the Confessor. He wore the stone on a ring during his coronation in 1042, and it became known as St. Edward’s Sapphire.

The Logan Sapphire Brooch, the second largest sapphire known (at 422.99 carats), is on display at the National Museum of Natural History in Washington, D.C. Image via Andrew Bossi/ Wikipedia.

Bottom line: The September birthstone is the sapphire. It is generally known as a blue gemstone, but it comes in many colors.

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

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

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Pioneer 11: Watching the Saturn watchers

Pioneer 11 captured this image in September, 1979, from a distance of 248,500 miles (400,000 km). The edge of Saturn’s disk can clearly be seen through a wide gap in the rings called the Cassini Division. The Keeler Gap can also be seen faintly silhouetted against the planet. Image via NASA/ Jet Propulsion Laboratory.

Pioneer 11 was the first earthly craft ever to fly past the planet Saturn. Its closest approach to the ringed planet was on September 1, 1979. And Patty Winter was at NASA’s Ames Research Center in Moffett Field, California – where the Pioneer project was managed – watching the Saturn watchers on that historic day. In the story below, Patty shares her memories. Here’s Watching the Saturn Watchers, by Patty Winter …

The scientists at Pioneer Saturn Mission Control are glued to their computer screens like Las Vegas tourists in front of one-armed bandits. What they don’t want to see is a field of dollar signs: The computer’s ironic way of saying they’ve just lost a multimillion-dollar spacecraft. Pioneer 11 is about to dart past the rings of Saturn. Theoretically, it will pass well outside them. But no one on Earth knows quite how far out the rings extend. And at 70,000 miles an hour (112 km/hr), a piece of ice and rock no bigger than a snowball could destroy Pioneer.

In an alcove-cum-TV studio at one side of the room, NASA’s Larry King is describing the scene for a worldwide audience. It’s Saturn-day, September 1, 1979, a few minutes before nine in the morning. The expected ring-crossing time is 9:02 a.m. PDT. The scientists here at Ames are giving the event a two-minute leeway on either side. They won’t consider the crossing successful until 9:04 has passed safely.

Watching Pioneer 11

Over at the Space Sciences Building, nearly a hundred journalists are equally attentive to their screens. The TV monitors allow them to peek over the shoulders of the mission controllers and see the data streaming in from Pioneer. At 9:00, Pioneer’s normal output of letters and numbers is still on the screen. In reality, we’re awaiting an event that has already happened. Pioneer crossed Saturn’s ring plane at 7:36 a.m. PDT. But it’s taken almost an hour and a half for the bits of information to make their way through a billion miles (1.6 billion km) of emptiness to the waiting antenna in Spain.

Click here to see current distance and location of Pioneer 10 and 11

This graphic shows the paths of the Pioneer and Voyager spacecrafts through and out of our solar system. Image via NASA.

Awaiting Pioneer’s signal

Just after 9:01 now, and Larry King is counting down the seconds to the predicted crossing time. He reaches zero, and the usual data are still on the screen. But the scientists and press people remain silent.

It’s impossible not to wish Pioneer well. Originally built only to explore Jupiter before tumbling its way to infinity, scientists redirected Pioneer 11 toward Saturn a few years later. It’s now giving us our first close-up look at the beautiful ringed planet before joining Pioneer 10 as one of the first artificial objects to leave our solar system.

The tiny Pioneers: only 9 by 9.5 feet (2.7 by 2.9 meters) big, alone in space except for radio contact with their small home planet, listening to instructions and beeping back their responses. Pioneer 10 is out past the orbit of Uranus. In 1987, it will cross the hypothetical boundary of our solar system and continue toward the constellation Taurus. Pioneer 11 is going in almost the opposite direction.

A message to the stars

Each of them carries a small gold plaque with a message from the people of the 3rd planet from Sol, just in case somebody out there finds one of the little travelers. It probably won’t happen, but it seems only polite to introduce ourselves, just in case.

The Pioneer plaque, which Carl Sagan helped design and place aboard the 1st 2 spacecraft ever to leave Earth for interstellar space, via Wikipedia.

View larger. | The plaque on the Pioneer spacecraft was inconspicuous among the dish and struts of the spacecraft. Image via NASA.

Pioneer’s extended journey

But back to Saturn, and back to the blue-and-white planet across the sun from it. The screens at Ames are still giving out good news, but has Pioneer actually gone past the rings yet? We don’t know for certain, since we’re not exactly sure where the rings are. And there have been some problems receiving the data. The people who designed Pioneer 11 never expected it to have to send back data for all these years and across all these miles. And who knew that the sun would send out a violent electromagnetic storm just a few days before the Saturn encounter?

Amazingly, we can still hear Pioneer’s tiny transmitter through the hash, and the instruments are working beautifully. Charlie Hall and the Pioneer team have been happy to be getting anything, so they’re overjoyed at the wealth of data they’ve been receiving. They have data on Saturn’s magnetic field and radiation belts, on its atmosphere and on its mysterious moon Iapetus.

Images from deep space

And the photographs! Black-and-white ones taken at various wavelengths to bring out different details of Saturn’s disk; color shots of the planet with the rings almost edge-on; and breathtaking color photos of the rings themselves: Those razor-thin rings, thousands of times as wide as they are thick, so ethereal and fragile looking. But it would take only one little pebble to cripple Pioneer.

This image from Pioneer 11 shows Saturn and its moon Titan. The irregularities in ring silhouette and shadow are due to technical anomalies in the preliminary data, which was later corrected. At the time this image was taken, Pioneer was 1,768,422 miles (2,846,000 km) from Saturn. But Pioneer 11’s path through Saturn’s outer rings ultimately took it within 13,000 miles (21,000 km) of the planet, where it discovered two new moons (almost smacking into one of them in September 1979) and a new “F” ring. Image via NASA Ames.

Pioneer phones home

We’re coming up on 9:03, and there’s a growing feeling at Ames that it’s going to be all right. An accident could happen at any time, of course, but Saturn’s gravitational field has attracted virtually all nearby material into the constantly shifting bands around its middle, so the rest of the vicinity is almost empty, or so the scientists hope. Now Larry King is telling us it’s 9:04, and the computer screens haven’t changed. Still that same reassuring mixture of letters and numbers, and no dollar signs.

Someone in Mission Control says loudly:

We made it.

Applause and a few whoops fill the press room. It isn’t a wild reaction. It’s not like watching Apollo 17 blaze into the Florida night and inwardly chanting, Go! Go! Go! After all, we can’t actually see this milestone. Pioneer can only take still photographs. The human reaction this time is more a sigh of relief, a happy feeling that a small emissary from Earth has been given a warm welcome by a neighbor as it heads for the stars.

Pioneer 11 took this image of Saturn on September 1, 1979. Image via Wikimedia Commons.

Bottom line: Patty Winter of Menlo Park, California, recalls the day that Pioneer 11 passed the rings of Saturn. The Pioneer mission was managed by NASA’s Ames Research Center in Moffett Field, California, which today maintains the Pioneer mission’s historical archive.

The post Pioneer 11: Watching the Saturn watchers first appeared on EarthSky.

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Pioneer 11 captured this image in September, 1979, from a distance of 248,500 miles (400,000 km). The edge of Saturn’s disk can clearly be seen through a wide gap in the rings called the Cassini Division. The Keeler Gap can also be seen faintly silhouetted against the planet. Image via NASA/ Jet Propulsion Laboratory.

Pioneer 11 was the first earthly craft ever to fly past the planet Saturn. Its closest approach to the ringed planet was on September 1, 1979. And Patty Winter was at NASA’s Ames Research Center in Moffett Field, California – where the Pioneer project was managed – watching the Saturn watchers on that historic day. In the story below, Patty shares her memories. Here’s Watching the Saturn Watchers, by Patty Winter …

The scientists at Pioneer Saturn Mission Control are glued to their computer screens like Las Vegas tourists in front of one-armed bandits. What they don’t want to see is a field of dollar signs: The computer’s ironic way of saying they’ve just lost a multimillion-dollar spacecraft. Pioneer 11 is about to dart past the rings of Saturn. Theoretically, it will pass well outside them. But no one on Earth knows quite how far out the rings extend. And at 70,000 miles an hour (112 km/hr), a piece of ice and rock no bigger than a snowball could destroy Pioneer.

In an alcove-cum-TV studio at one side of the room, NASA’s Larry King is describing the scene for a worldwide audience. It’s Saturn-day, September 1, 1979, a few minutes before nine in the morning. The expected ring-crossing time is 9:02 a.m. PDT. The scientists here at Ames are giving the event a two-minute leeway on either side. They won’t consider the crossing successful until 9:04 has passed safely.

Watching Pioneer 11

Over at the Space Sciences Building, nearly a hundred journalists are equally attentive to their screens. The TV monitors allow them to peek over the shoulders of the mission controllers and see the data streaming in from Pioneer. At 9:00, Pioneer’s normal output of letters and numbers is still on the screen. In reality, we’re awaiting an event that has already happened. Pioneer crossed Saturn’s ring plane at 7:36 a.m. PDT. But it’s taken almost an hour and a half for the bits of information to make their way through a billion miles (1.6 billion km) of emptiness to the waiting antenna in Spain.

Click here to see current distance and location of Pioneer 10 and 11

This graphic shows the paths of the Pioneer and Voyager spacecrafts through and out of our solar system. Image via NASA.

Awaiting Pioneer’s signal

Just after 9:01 now, and Larry King is counting down the seconds to the predicted crossing time. He reaches zero, and the usual data are still on the screen. But the scientists and press people remain silent.

It’s impossible not to wish Pioneer well. Originally built only to explore Jupiter before tumbling its way to infinity, scientists redirected Pioneer 11 toward Saturn a few years later. It’s now giving us our first close-up look at the beautiful ringed planet before joining Pioneer 10 as one of the first artificial objects to leave our solar system.

The tiny Pioneers: only 9 by 9.5 feet (2.7 by 2.9 meters) big, alone in space except for radio contact with their small home planet, listening to instructions and beeping back their responses. Pioneer 10 is out past the orbit of Uranus. In 1987, it will cross the hypothetical boundary of our solar system and continue toward the constellation Taurus. Pioneer 11 is going in almost the opposite direction.

A message to the stars

Each of them carries a small gold plaque with a message from the people of the 3rd planet from Sol, just in case somebody out there finds one of the little travelers. It probably won’t happen, but it seems only polite to introduce ourselves, just in case.

The Pioneer plaque, which Carl Sagan helped design and place aboard the 1st 2 spacecraft ever to leave Earth for interstellar space, via Wikipedia.

View larger. | The plaque on the Pioneer spacecraft was inconspicuous among the dish and struts of the spacecraft. Image via NASA.

Pioneer’s extended journey

But back to Saturn, and back to the blue-and-white planet across the sun from it. The screens at Ames are still giving out good news, but has Pioneer actually gone past the rings yet? We don’t know for certain, since we’re not exactly sure where the rings are. And there have been some problems receiving the data. The people who designed Pioneer 11 never expected it to have to send back data for all these years and across all these miles. And who knew that the sun would send out a violent electromagnetic storm just a few days before the Saturn encounter?

Amazingly, we can still hear Pioneer’s tiny transmitter through the hash, and the instruments are working beautifully. Charlie Hall and the Pioneer team have been happy to be getting anything, so they’re overjoyed at the wealth of data they’ve been receiving. They have data on Saturn’s magnetic field and radiation belts, on its atmosphere and on its mysterious moon Iapetus.

Images from deep space

And the photographs! Black-and-white ones taken at various wavelengths to bring out different details of Saturn’s disk; color shots of the planet with the rings almost edge-on; and breathtaking color photos of the rings themselves: Those razor-thin rings, thousands of times as wide as they are thick, so ethereal and fragile looking. But it would take only one little pebble to cripple Pioneer.

This image from Pioneer 11 shows Saturn and its moon Titan. The irregularities in ring silhouette and shadow are due to technical anomalies in the preliminary data, which was later corrected. At the time this image was taken, Pioneer was 1,768,422 miles (2,846,000 km) from Saturn. But Pioneer 11’s path through Saturn’s outer rings ultimately took it within 13,000 miles (21,000 km) of the planet, where it discovered two new moons (almost smacking into one of them in September 1979) and a new “F” ring. Image via NASA Ames.

Pioneer phones home

We’re coming up on 9:03, and there’s a growing feeling at Ames that it’s going to be all right. An accident could happen at any time, of course, but Saturn’s gravitational field has attracted virtually all nearby material into the constantly shifting bands around its middle, so the rest of the vicinity is almost empty, or so the scientists hope. Now Larry King is telling us it’s 9:04, and the computer screens haven’t changed. Still that same reassuring mixture of letters and numbers, and no dollar signs.

Someone in Mission Control says loudly:

We made it.

Applause and a few whoops fill the press room. It isn’t a wild reaction. It’s not like watching Apollo 17 blaze into the Florida night and inwardly chanting, Go! Go! Go! After all, we can’t actually see this milestone. Pioneer can only take still photographs. The human reaction this time is more a sigh of relief, a happy feeling that a small emissary from Earth has been given a warm welcome by a neighbor as it heads for the stars.

Pioneer 11 took this image of Saturn on September 1, 1979. Image via Wikimedia Commons.

Bottom line: Patty Winter of Menlo Park, California, recalls the day that Pioneer 11 passed the rings of Saturn. The Pioneer mission was managed by NASA’s Ames Research Center in Moffett Field, California, which today maintains the Pioneer mission’s historical archive.

The post Pioneer 11: Watching the Saturn watchers first appeared on EarthSky.

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Will El Niño become supersized? What experts are saying

This is the sea surface temperature anomaly map for August 30, 2026. An El Niño is when sea surface temperatures in the central and eastern tropical Pacific Ocean become unusually warm, with a 0.5° Celsius (0.9° Fahrenheit) above the long-term average. Image via University of Maine.

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Will El Niño become supersized?

El Niño is officially here, NOAA’s National Weather Service said in June. The conditions were met after the sea surface temperatures in the equatorial Pacific Ocean rose 0.5°C above average for several months. And now NOAA says there’s a 90% or greater chance we see a very strong El Niño between September 2026 and January 2027.

Climate scientist Daniel Swain of the University of California said there is a:

high likelihood (~70%) that the 2026 event will become the strongest on record (since at least 1950) later this year, likely peaking in intensity between October and December.

The Columbia Climate School agrees. It said on August 19:

Despite some uncertainty in the projected peak intensity, the forecast consensus is clear: a strong El Niño is highly likely to develop and persist through late 2026.

Swain also discussed what the global effects of this supersized El Niño could be:

By increasing the total amount of heat and water vapor in the Earth’s atmosphere, and by shifting global storm tracks, this event will likely contribute to significant regional drought and flood events, as well as extreme heat. Additionally, the temporary effects from this very strong El Niño event will amplify the effect of long-term warming from climate change, greatly elevating the likelihood of record-breaking global temperatures and extreme weather events during 2026-2027.

A super El Niño

Some meteorologists have been calling the very strong conditions a super El Niño. El Niño is the warm phase of a weather pattern based on the sea surface temperatures in the eastern Pacific Ocean. This pattern drives weather, including temperatures and amounts of precipitation. El Niño conditions bring different weather to different places. You can see the overall trends in the charts below.

An El Niño increases the likelihood of wetter weather in the southern and eastern U.S., with dry conditions near the Great Lakes and warm conditions along the upper tier of the U.S. Image via NOAA/ National Ocean Service.

El Niño conditions in the tropical Pacific are known to shift rainfall patterns in many different parts of the world. The regions and seasons shown on the map indicate typical but not guaranteed impacts of El Niño. Image via Columbia Climate School.

What to expect from El Niño

There are some overall patterns that weather follows when we are in El Niño conditions. But you’ll still want to stay weather aware. As Ken Graham, director of NOAA’s National Weather Service, said:

Every El Nino is not the same; each one is unique with its own imprint on our weather.

But here’s a look at some of the likely weather scenarios during El Niño.

An El Niño usually brings higher global temperatures. The excess heat in the Pacific Ocean eventually enters the atmosphere. This causes warmer global temperatures. However, the rise in temperatures often has a lag time of a few months.

As Northern Illinois University meteorology professor Victor Gensini told PBS:

A strong El Niño could plausibly push global temperatures to new record levels in late 2026 and into 2027.

In the summer, El Niño can dampen hurricane formation in the Atlantic. And so far, the hurricane in the Atlantic has indeed been relatively quiet. Colorado State University even revised its earlier, already-low hurricane forecast downward in July.

El Niño has officially arrived. Watch the sea surface temperatures change from January 1 to June 8, 2026. The red shows warmer-than-average sea surface temperatures pooling in the eastern Pacific Ocean near the equator. Image via NOAA.

Winter this season

It’s in winter that we feel El Niño the strongest. Often the jet stream will drop south, steering storms into California and Arizona and bringing much-needed rain. If the jet stream swings southward, then the southern and eastern U.S. can expect wetter and cooler weather. Meanwhile, drier weather could prevail in the northern U.S. and Great Lakes region.

Read more: Lake Powell hits record low, continues to drop

Across the globe, El Niño brings drought conditions to places such as Australia, India and central Africa. And it can bring heavy rains to southern South America and eastern Africa.

World Meteorological Organization (WMO) Secretary-General Celeste Saulo said on June 2, 2026:

We need to prepare for a potentially strong El Niño event, which will exacerbate drought and heavy rainfall and increase the risk of heatwaves both on land and in the ocean. The most recent El Niño, in 2023-24, was one of the five strongest on record and it played a role in the record global temperatures we saw in 2024.

Just like any weather event, preparation is key. The WMO said that nearly everywhere can expect above average temperatures for June to August.

WMO urges people to prepare

On Tuesday, June 2, 2026, the WMO, based in Geneva, Switzerland, urged people to prepare for El Niño. The WMO, a specialized agency of the United Nations that focuses on weather, climate and water resources, said:

Fueled by unusually warm ocean waters in the tropical Pacific, El Niño conditions are developing and are set to influence global temperature and rainfall patterns, increasing the risk of extreme weather over the coming months.

UN Secretary-General António Guterres did not hold back in a statement:

El Niño conditions will pour fuel on the fire of a warming world. Impacts will hit even harder, travel even farther, and cross borders with devastating speed. The only effective response is climate action equal to the crisis: ending the addiction to fossil fuels, accelerating the shift to renewables, protecting the most vulnerable, and delivering early warning systems for all.

Read more: The Atlantic hurricane season forecast for 2026 is out!

What is a super El Niño?

So what is a super El Niño compared to an El Niño? Let’s start by looking closer at a typical El Niño. There are three types of conditions that can guide global weather: El Niño, La Niña and neutral. These three conditions make up ENSO, or the El Niño–Southern Oscillation. ENSO is a natural climate pattern in the tropical Pacific Ocean that shifts between warm and cool phases. El Niño is the warm phase and La Niña is the cool phase. And these phases influence weather around the world, including rainfall, droughts and storms.

So an average El Niño occurs when warm water pools up in the eastern Pacific Ocean around the equator. Once the temperatures reach 0.5 degrees Celsius (0.9 F) warmer than normal in the sea surface, an El Niño has formed. El Niño conditions can last for up to a year.

A super El Niño is a stronger event. Meteorologists often call it a super El Niño when the sea surface temperature anomalies peak at about 2.0° C (3.6 F) above normal. And currently, some models are calling for the coming El Niño to exceed 2.5° C (4.5 F) above the seasonal average by October.

Staying safe in extreme heat

From EarthSky’s weather author, meteorologist Rachel Duensing:

Staying safe in extreme heat can vary a bit depending on your situation. But the main idea is to avoid the heat as much as possible. If you are able to stay inside, ideally in air-conditioning (A/C), this is your best option. But if you cannot avoid the hot weather, there are things you can do. Take frequent breaks in the shade. Make sure you’re staying hydrated. Wear light-colored, loose-fitting clothing. And pay close attention to how you’re feeling as the day goes on.

If you, or someone you are with, is sweating heavily, feeling weak, tired, dizzy or nauseated, these could be signs of heat exhaustion. Immediately move yourself or the other person into A/C. Loosen their clothing, give them sips of cool water and put cold compresses on their body.

If someone is acting confused and slurring their speech, has red and hot skin or passes out, this is likely a heat stroke. They need medical attention immediately! Call 911. While you wait for help to arrive, move the person to A/C, add cool compresses to lower their body temperature, but do not give them anything to drink.

The heat can also be more dangerous to the very young, the very old, people with chronic medical conditions and pregnant women. In addition, the unhoused and lower income communities, who may not be able to afford to run their air-conditioning, are also at risk. Check on your friends, family and neighbors before, during and after extreme heat.

Bottom line: El Niño is here. But will it become supersized? NOAA says there’s a 90% or greater chance for El Niño to become “very strong” between September and January.

Via:

NOAA

National Weather Service (NOAA)

Yale Climate Connections

World Meteorological Organization

The post Will El Niño become supersized? What experts are saying first appeared on EarthSky.

from EarthSky https://ift.tt/Ez9CNPb

This is the sea surface temperature anomaly map for August 30, 2026. An El Niño is when sea surface temperatures in the central and eastern tropical Pacific Ocean become unusually warm, with a 0.5° Celsius (0.9° Fahrenheit) above the long-term average. Image via University of Maine.

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

Will El Niño become supersized?

El Niño is officially here, NOAA’s National Weather Service said in June. The conditions were met after the sea surface temperatures in the equatorial Pacific Ocean rose 0.5°C above average for several months. And now NOAA says there’s a 90% or greater chance we see a very strong El Niño between September 2026 and January 2027.

Climate scientist Daniel Swain of the University of California said there is a:

high likelihood (~70%) that the 2026 event will become the strongest on record (since at least 1950) later this year, likely peaking in intensity between October and December.

The Columbia Climate School agrees. It said on August 19:

Despite some uncertainty in the projected peak intensity, the forecast consensus is clear: a strong El Niño is highly likely to develop and persist through late 2026.

Swain also discussed what the global effects of this supersized El Niño could be:

By increasing the total amount of heat and water vapor in the Earth’s atmosphere, and by shifting global storm tracks, this event will likely contribute to significant regional drought and flood events, as well as extreme heat. Additionally, the temporary effects from this very strong El Niño event will amplify the effect of long-term warming from climate change, greatly elevating the likelihood of record-breaking global temperatures and extreme weather events during 2026-2027.

A super El Niño

Some meteorologists have been calling the very strong conditions a super El Niño. El Niño is the warm phase of a weather pattern based on the sea surface temperatures in the eastern Pacific Ocean. This pattern drives weather, including temperatures and amounts of precipitation. El Niño conditions bring different weather to different places. You can see the overall trends in the charts below.

An El Niño increases the likelihood of wetter weather in the southern and eastern U.S., with dry conditions near the Great Lakes and warm conditions along the upper tier of the U.S. Image via NOAA/ National Ocean Service.

El Niño conditions in the tropical Pacific are known to shift rainfall patterns in many different parts of the world. The regions and seasons shown on the map indicate typical but not guaranteed impacts of El Niño. Image via Columbia Climate School.

What to expect from El Niño

There are some overall patterns that weather follows when we are in El Niño conditions. But you’ll still want to stay weather aware. As Ken Graham, director of NOAA’s National Weather Service, said:

Every El Nino is not the same; each one is unique with its own imprint on our weather.

But here’s a look at some of the likely weather scenarios during El Niño.

An El Niño usually brings higher global temperatures. The excess heat in the Pacific Ocean eventually enters the atmosphere. This causes warmer global temperatures. However, the rise in temperatures often has a lag time of a few months.

As Northern Illinois University meteorology professor Victor Gensini told PBS:

A strong El Niño could plausibly push global temperatures to new record levels in late 2026 and into 2027.

In the summer, El Niño can dampen hurricane formation in the Atlantic. And so far, the hurricane in the Atlantic has indeed been relatively quiet. Colorado State University even revised its earlier, already-low hurricane forecast downward in July.

El Niño has officially arrived. Watch the sea surface temperatures change from January 1 to June 8, 2026. The red shows warmer-than-average sea surface temperatures pooling in the eastern Pacific Ocean near the equator. Image via NOAA.

Winter this season

It’s in winter that we feel El Niño the strongest. Often the jet stream will drop south, steering storms into California and Arizona and bringing much-needed rain. If the jet stream swings southward, then the southern and eastern U.S. can expect wetter and cooler weather. Meanwhile, drier weather could prevail in the northern U.S. and Great Lakes region.

Read more: Lake Powell hits record low, continues to drop

Across the globe, El Niño brings drought conditions to places such as Australia, India and central Africa. And it can bring heavy rains to southern South America and eastern Africa.

World Meteorological Organization (WMO) Secretary-General Celeste Saulo said on June 2, 2026:

We need to prepare for a potentially strong El Niño event, which will exacerbate drought and heavy rainfall and increase the risk of heatwaves both on land and in the ocean. The most recent El Niño, in 2023-24, was one of the five strongest on record and it played a role in the record global temperatures we saw in 2024.

Just like any weather event, preparation is key. The WMO said that nearly everywhere can expect above average temperatures for June to August.

WMO urges people to prepare

On Tuesday, June 2, 2026, the WMO, based in Geneva, Switzerland, urged people to prepare for El Niño. The WMO, a specialized agency of the United Nations that focuses on weather, climate and water resources, said:

Fueled by unusually warm ocean waters in the tropical Pacific, El Niño conditions are developing and are set to influence global temperature and rainfall patterns, increasing the risk of extreme weather over the coming months.

UN Secretary-General António Guterres did not hold back in a statement:

El Niño conditions will pour fuel on the fire of a warming world. Impacts will hit even harder, travel even farther, and cross borders with devastating speed. The only effective response is climate action equal to the crisis: ending the addiction to fossil fuels, accelerating the shift to renewables, protecting the most vulnerable, and delivering early warning systems for all.

Read more: The Atlantic hurricane season forecast for 2026 is out!

What is a super El Niño?

So what is a super El Niño compared to an El Niño? Let’s start by looking closer at a typical El Niño. There are three types of conditions that can guide global weather: El Niño, La Niña and neutral. These three conditions make up ENSO, or the El Niño–Southern Oscillation. ENSO is a natural climate pattern in the tropical Pacific Ocean that shifts between warm and cool phases. El Niño is the warm phase and La Niña is the cool phase. And these phases influence weather around the world, including rainfall, droughts and storms.

So an average El Niño occurs when warm water pools up in the eastern Pacific Ocean around the equator. Once the temperatures reach 0.5 degrees Celsius (0.9 F) warmer than normal in the sea surface, an El Niño has formed. El Niño conditions can last for up to a year.

A super El Niño is a stronger event. Meteorologists often call it a super El Niño when the sea surface temperature anomalies peak at about 2.0° C (3.6 F) above normal. And currently, some models are calling for the coming El Niño to exceed 2.5° C (4.5 F) above the seasonal average by October.

Staying safe in extreme heat

From EarthSky’s weather author, meteorologist Rachel Duensing:

Staying safe in extreme heat can vary a bit depending on your situation. But the main idea is to avoid the heat as much as possible. If you are able to stay inside, ideally in air-conditioning (A/C), this is your best option. But if you cannot avoid the hot weather, there are things you can do. Take frequent breaks in the shade. Make sure you’re staying hydrated. Wear light-colored, loose-fitting clothing. And pay close attention to how you’re feeling as the day goes on.

If you, or someone you are with, is sweating heavily, feeling weak, tired, dizzy or nauseated, these could be signs of heat exhaustion. Immediately move yourself or the other person into A/C. Loosen their clothing, give them sips of cool water and put cold compresses on their body.

If someone is acting confused and slurring their speech, has red and hot skin or passes out, this is likely a heat stroke. They need medical attention immediately! Call 911. While you wait for help to arrive, move the person to A/C, add cool compresses to lower their body temperature, but do not give them anything to drink.

The heat can also be more dangerous to the very young, the very old, people with chronic medical conditions and pregnant women. In addition, the unhoused and lower income communities, who may not be able to afford to run their air-conditioning, are also at risk. Check on your friends, family and neighbors before, during and after extreme heat.

Bottom line: El Niño is here. But will it become supersized? NOAA says there’s a 90% or greater chance for El Niño to become “very strong” between September and January.

Via:

NOAA

National Weather Service (NOAA)

Yale Climate Connections

World Meteorological Organization

The post Will El Niño become supersized? What experts are saying first appeared on EarthSky.

from EarthSky https://ift.tt/Ez9CNPb

How do lava-world exoplanets keep their atmospheres?

Artist’s concept from NASA. Lava-world exoplanets like this one might be expected to be airless. But some have air. How?

• Lava worlds are rocky exoplanets that orbit so close to their stars that intense heat can melt rock on their surfaces. Scientists had expected that they would lose their atmospheres due to the intense radiation from their stars.
• But it turns out some lava-worlds do have atmospheres, even thick ones! How is that possible?
• A new model from researchers at Stanford University shows that gases slowly escaping from below the planets’ surfaces can keep their atmospheres sustained.

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

Some lava-world exoplanets have atmospheres

Exoplanets that orbit very close to their stars are always in danger of losing their atmospheres. That’s because the radiation and stellar winds from the stars can erode the atmospheres until there’s little to nothing left. Some of these planets are rocky lava-worlds; the intense heat from the nearby star has melted rock on their surfaces. Scientists expect such planets to be airless. But some of them do still have their atmospheres, even thick atmospheres.

How is that possible? A new study, led by researchers at Stanford University in California, suggests an explanation. The researchers said on August 25, 2026, that gases slowly escaping from below the planets’ surfaces might replenish the gases that have been lost. The researchers published their peer-reviewed results in The Astrophysical Journal Letters on August 25, 2026.

That escape of gas into space is called outgassing. According to the new study, these atmospheres could last for billions of years.

View larger. | Here’s an artist’s concept of exoplanet TOI-561b. The planet lies in the newly proposed “cosmic sandbar,” where some lava-world exoplanets may retain atmospheres despite intense stellar radiation. Image via Image via NASA/ ESA/ CSA/ Ralf Crawford (STScI)/ Stanford University.

Sandbar, shoreline, valley

According to the new model, these lava worlds exist on a kinda of cosmic sandbar. What does that mean?

Prior to this new study, astronomers began speaking of a cosmic shoreline. They mean it to imply the boundary region in a distant solar system – at a particular distance from the central star – beyond which rocky exoplanets can retain atmospheres. Think of the shoreline as the dividing line between “has air” and “airless.”

Between this shoreline and the hotter sandbar, planets can lose their atmospheres and fail to replenish them. Astronomers refer that region of a distant solar system as an airless valley.

But now comes the cosmic sandbar: the unexpectedly hot region where some lava worlds can maintain atmospheres because gases released from their molten interiors replenish what stellar radiation strips away.

55 Cancri e is a good example. It’s a super-Earth almost eight times the mass of Earth. It orbits its star about 20 times closer than Mercury orbits the sun. Yet is has a thick atmosphere. The James Webb Space Telescope discovered that atmosphere – the first found on a rocky exoplanet – in 2024.

View larger. | This graphic shows the differences between the cosmic sandbar, the wireless valley and the cosmic shoreline. Image via Nguyen et al. 2026/ The Astrophysical Journal Letters.

astrobiology.com/2026/08/26/w… #astrobiology #exoplanet

— Astrobiology (@astrobiology.bsky.social) 2026-08-26T19:39:24.014Z

Continuous magmatic outgassing allows ultra-hot lava worlds to defy the cosmic shoreline theory and sustain thick atmospheres despite intense stellar radiation. https://ift.tt/UZzI28d…

— Labroots Earth & Environmental Sciences (@earth-lr.bsky.social) 2026-08-26T18:32:12.623Z

The ‘cosmic sandbar’

The research team has proposed a new region around stars called the “cosmic sandbar.” It is an extension of the “cosmic shoreline,” which is analogous to shorelines on Earth between land and water. For stars, it represents the boundary where a planet can keep or lose its atmosphere. In our solar system, Earth and Venus are on the cosmic shoreline. They remain cool enough that radiation from the sun doesn’t burn off their atmospheres.

But there’s a catch. Some lava-worlds are closer to their stars than that cosmic shoreline boundary. So how do they maintain their atmospheres?

The researchers have called this region the cosmic sandbar. It is analogous to the sandy ridges that form offshore in oceans. As lead author Barron Nguyen at the Stanford Doerr School of Sustainability explained it:

These lava-worlds have pointed to something being wrong with the cosmic shoreline boundary, but we’ve found a way for them to preserve their atmospheres by proposing a new regime beyond it.

Co-author Laura Schaefer added:

Where the shoreline boundary is between airless worlds and those capable of sustaining an atmosphere has been a major open question in planetary science. The new model expands our understanding of this boundary and the factors that go into determining where it lies for specific stars and planets.

View larger. | Artist’s concept of 55 Cancri e, a lava-world exoplanet 41 light-years from Earth. Image via NASA.

The ‘airless valley’

There’s also another region called the “airless valley.” That’s between the shoreline and the sandbar. The planets are close enough to their stars for their atmospheres to be stripped away, but then they cool off too quickly after formation for those atmospheres to be replenished.

Barron Nguyen at Stanford University led the new study about lava-worlds and their atmospheres. Image via Barron Nguyen.

Follow the atmospheres

One of the major – and most exciting – aspects of studying exoplanets is the search for life. To do this, scientists “follow the atmospheres.” As a first step, they need to find rocky planets that have atmospheres. Then they can analyze those atmospheres for possible biosignatures, chemical fingerprints of living organisms. Nguyen said:

Scientists have been interested in figuring out which planets have atmospheres and which do not, because that’s the first step of looking at planetary habitability.

That’s why planets that do have atmospheres, despite being so close to their stars, is so interesting. It expands the range of planets that could be potentially habitable. Although in the case of lava-worlds, they are likely simply too hot for life. At least on the surface.

The cosmic shoreline might not be as definitive as previously thought when determining which exoplanets could be habitable. It’s not completely a lost cause though, either. Nguyen said:

A major takeaway from our study is that the cosmic shoreline isn’t a lost cause. There had been some pessimism about it because of these lava worlds, but now we know there’s a broader set of parameters that can enable a planet to generate and maintain an atmosphere.

Scientists also reported finding a atmosphere on another lava-world, TOI-561 b, earlier this year. It is a super-Earth 560 light-years away.

Bottom line: A new study from researchers at Stanford University helps explain how hot lava-world exoplanets orbiting close to their stars can maintain their atmospheres.

Source: An Evolving Cosmic Shoreline and Sandbar Bounding the Rocky Airless Valley

Via Stanford University

Read more: Possible atmosphere on rocky exoplanet found for 1st time

Read more: Atmosphere on lava planet is an exciting surprise

The post How do lava-world exoplanets keep their atmospheres? first appeared on EarthSky.

from EarthSky https://ift.tt/NHIc8FB

Artist’s concept from NASA. Lava-world exoplanets like this one might be expected to be airless. But some have air. How?

• Lava worlds are rocky exoplanets that orbit so close to their stars that intense heat can melt rock on their surfaces. Scientists had expected that they would lose their atmospheres due to the intense radiation from their stars.
• But it turns out some lava-worlds do have atmospheres, even thick ones! How is that possible?
• A new model from researchers at Stanford University shows that gases slowly escaping from below the planets’ surfaces can keep their atmospheres sustained.

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

Some lava-world exoplanets have atmospheres

Exoplanets that orbit very close to their stars are always in danger of losing their atmospheres. That’s because the radiation and stellar winds from the stars can erode the atmospheres until there’s little to nothing left. Some of these planets are rocky lava-worlds; the intense heat from the nearby star has melted rock on their surfaces. Scientists expect such planets to be airless. But some of them do still have their atmospheres, even thick atmospheres.

How is that possible? A new study, led by researchers at Stanford University in California, suggests an explanation. The researchers said on August 25, 2026, that gases slowly escaping from below the planets’ surfaces might replenish the gases that have been lost. The researchers published their peer-reviewed results in The Astrophysical Journal Letters on August 25, 2026.

That escape of gas into space is called outgassing. According to the new study, these atmospheres could last for billions of years.

View larger. | Here’s an artist’s concept of exoplanet TOI-561b. The planet lies in the newly proposed “cosmic sandbar,” where some lava-world exoplanets may retain atmospheres despite intense stellar radiation. Image via Image via NASA/ ESA/ CSA/ Ralf Crawford (STScI)/ Stanford University.

Sandbar, shoreline, valley

According to the new model, these lava worlds exist on a kinda of cosmic sandbar. What does that mean?

Prior to this new study, astronomers began speaking of a cosmic shoreline. They mean it to imply the boundary region in a distant solar system – at a particular distance from the central star – beyond which rocky exoplanets can retain atmospheres. Think of the shoreline as the dividing line between “has air” and “airless.”

Between this shoreline and the hotter sandbar, planets can lose their atmospheres and fail to replenish them. Astronomers refer that region of a distant solar system as an airless valley.

But now comes the cosmic sandbar: the unexpectedly hot region where some lava worlds can maintain atmospheres because gases released from their molten interiors replenish what stellar radiation strips away.

55 Cancri e is a good example. It’s a super-Earth almost eight times the mass of Earth. It orbits its star about 20 times closer than Mercury orbits the sun. Yet is has a thick atmosphere. The James Webb Space Telescope discovered that atmosphere – the first found on a rocky exoplanet – in 2024.

View larger. | This graphic shows the differences between the cosmic sandbar, the wireless valley and the cosmic shoreline. Image via Nguyen et al. 2026/ The Astrophysical Journal Letters.

astrobiology.com/2026/08/26/w… #astrobiology #exoplanet

— Astrobiology (@astrobiology.bsky.social) 2026-08-26T19:39:24.014Z

Continuous magmatic outgassing allows ultra-hot lava worlds to defy the cosmic shoreline theory and sustain thick atmospheres despite intense stellar radiation. https://ift.tt/UZzI28d…

— Labroots Earth & Environmental Sciences (@earth-lr.bsky.social) 2026-08-26T18:32:12.623Z

The ‘cosmic sandbar’

The research team has proposed a new region around stars called the “cosmic sandbar.” It is an extension of the “cosmic shoreline,” which is analogous to shorelines on Earth between land and water. For stars, it represents the boundary where a planet can keep or lose its atmosphere. In our solar system, Earth and Venus are on the cosmic shoreline. They remain cool enough that radiation from the sun doesn’t burn off their atmospheres.

But there’s a catch. Some lava-worlds are closer to their stars than that cosmic shoreline boundary. So how do they maintain their atmospheres?

The researchers have called this region the cosmic sandbar. It is analogous to the sandy ridges that form offshore in oceans. As lead author Barron Nguyen at the Stanford Doerr School of Sustainability explained it:

These lava-worlds have pointed to something being wrong with the cosmic shoreline boundary, but we’ve found a way for them to preserve their atmospheres by proposing a new regime beyond it.

Co-author Laura Schaefer added:

Where the shoreline boundary is between airless worlds and those capable of sustaining an atmosphere has been a major open question in planetary science. The new model expands our understanding of this boundary and the factors that go into determining where it lies for specific stars and planets.

View larger. | Artist’s concept of 55 Cancri e, a lava-world exoplanet 41 light-years from Earth. Image via NASA.

The ‘airless valley’

There’s also another region called the “airless valley.” That’s between the shoreline and the sandbar. The planets are close enough to their stars for their atmospheres to be stripped away, but then they cool off too quickly after formation for those atmospheres to be replenished.

Barron Nguyen at Stanford University led the new study about lava-worlds and their atmospheres. Image via Barron Nguyen.

Follow the atmospheres

One of the major – and most exciting – aspects of studying exoplanets is the search for life. To do this, scientists “follow the atmospheres.” As a first step, they need to find rocky planets that have atmospheres. Then they can analyze those atmospheres for possible biosignatures, chemical fingerprints of living organisms. Nguyen said:

Scientists have been interested in figuring out which planets have atmospheres and which do not, because that’s the first step of looking at planetary habitability.

That’s why planets that do have atmospheres, despite being so close to their stars, is so interesting. It expands the range of planets that could be potentially habitable. Although in the case of lava-worlds, they are likely simply too hot for life. At least on the surface.

The cosmic shoreline might not be as definitive as previously thought when determining which exoplanets could be habitable. It’s not completely a lost cause though, either. Nguyen said:

A major takeaway from our study is that the cosmic shoreline isn’t a lost cause. There had been some pessimism about it because of these lava worlds, but now we know there’s a broader set of parameters that can enable a planet to generate and maintain an atmosphere.

Scientists also reported finding a atmosphere on another lava-world, TOI-561 b, earlier this year. It is a super-Earth 560 light-years away.

Bottom line: A new study from researchers at Stanford University helps explain how hot lava-world exoplanets orbiting close to their stars can maintain their atmospheres.

Source: An Evolving Cosmic Shoreline and Sandbar Bounding the Rocky Airless Valley

Via Stanford University

Read more: Possible atmosphere on rocky exoplanet found for 1st time

Read more: Atmosphere on lava planet is an exciting surprise

The post How do lava-world exoplanets keep their atmospheres? first appeared on EarthSky.

from EarthSky https://ift.tt/NHIc8FB