NASA’s Curiosity rover captured this view of a Martian dawn on August 11, 2026. NASA just released it to the public on Tuesday. Now, Curiosity is headed toward those distant, sunlit crags. See the full panorama below. Image via NASA/ JPL-Caltech/ MSSS.
NASA’s Curiosity rover has been exploring the Mount Sharp region of Mars since it arrived in 2012. Now, on October 6, 2026, NASA has released this new pic of a Martian dawn, which illuminates the play of light on the cliffs and crags of the region.
The Mars Curiosity rover captured this image back on August 11, 2026, which was the 4,982nd Martian day, or sol. And since then, Curiosity has surpassed the 5,000 sol mark and is still going strong!
An odd feature on Mars
NASA said the crags on the horizon are known as yardangs. These are landscape protrusions carved out of bedrock. The yardangs protrude on the northwestern reaches of Mount Sharp.
Mount Sharp is a 3-mile-tall (5-km-tall) mountain, while the yardangs extend horizontally about 10 miles (16 km) across.
But scientists think something is odd about this yardang layer on Mars. Ashwin Vasavada, Curiosity project scientist of NASA’s Jet Propulsion Laboratory, said:
The yardang layer looks out of place. It’s the wrong color, the layers tilt at an odd angle, and it almost appears plastered on. But that’s what makes it exciting to reach.
No one is sure exactly what created this layer, but one idea is it may be ash deposited by ancient volcanic eruptions.
View larger. | Here’s the full panorama of the Martian dawn with all 6 shots from NASA’s Curiosity rover. NASA said: “Unlike most images from the rover’s Mastcam, this one was processed without the usual white balancing; an artistic choice that preserves the early morning appearance.” Image via NASA/ JPL-Caltech/ MSSS.
More about Mount Sharp
Mount Sharp lies within Gale Crater. And it makes up the crater’s central peak. Curiosity has now climbed 0.6 miles (1 km) of elevation as it ascends toward Mount Sharp. In fact, that’s the highest ever climbed on Mars, and the rover is still going.
Scientists say Mount Sharp is made of layers that formed over time. Lakes and streams once flowed here. But eventually, the water dried up and left behind salty deposits. The wind then eroded away some of the material, leaving behind the crags or yardangs.
Now the little Curiosity rover will roll onward, perhaps reaching the base of the yardangs by 2027. We look forward to seeing these jagged formations from a closer point of view!
This is an artist’s concept looking down at Mount Sharp on Mars. The circled area denotes the location of the yardangs, or crags, in the top image. Image via NASA/ JPL-Caltech/ ESA/ DLR/ FU Berlin/ MSSS.
Bottom line: On October 6, 2026, NASA released an image of Martian dawn from the Curiosity rover. The image captures a pale light illuminating distant cliffs and crags.
NASA’s Curiosity rover captured this view of a Martian dawn on August 11, 2026. NASA just released it to the public on Tuesday. Now, Curiosity is headed toward those distant, sunlit crags. See the full panorama below. Image via NASA/ JPL-Caltech/ MSSS.
NASA’s Curiosity rover has been exploring the Mount Sharp region of Mars since it arrived in 2012. Now, on October 6, 2026, NASA has released this new pic of a Martian dawn, which illuminates the play of light on the cliffs and crags of the region.
The Mars Curiosity rover captured this image back on August 11, 2026, which was the 4,982nd Martian day, or sol. And since then, Curiosity has surpassed the 5,000 sol mark and is still going strong!
An odd feature on Mars
NASA said the crags on the horizon are known as yardangs. These are landscape protrusions carved out of bedrock. The yardangs protrude on the northwestern reaches of Mount Sharp.
Mount Sharp is a 3-mile-tall (5-km-tall) mountain, while the yardangs extend horizontally about 10 miles (16 km) across.
But scientists think something is odd about this yardang layer on Mars. Ashwin Vasavada, Curiosity project scientist of NASA’s Jet Propulsion Laboratory, said:
The yardang layer looks out of place. It’s the wrong color, the layers tilt at an odd angle, and it almost appears plastered on. But that’s what makes it exciting to reach.
No one is sure exactly what created this layer, but one idea is it may be ash deposited by ancient volcanic eruptions.
View larger. | Here’s the full panorama of the Martian dawn with all 6 shots from NASA’s Curiosity rover. NASA said: “Unlike most images from the rover’s Mastcam, this one was processed without the usual white balancing; an artistic choice that preserves the early morning appearance.” Image via NASA/ JPL-Caltech/ MSSS.
More about Mount Sharp
Mount Sharp lies within Gale Crater. And it makes up the crater’s central peak. Curiosity has now climbed 0.6 miles (1 km) of elevation as it ascends toward Mount Sharp. In fact, that’s the highest ever climbed on Mars, and the rover is still going.
Scientists say Mount Sharp is made of layers that formed over time. Lakes and streams once flowed here. But eventually, the water dried up and left behind salty deposits. The wind then eroded away some of the material, leaving behind the crags or yardangs.
Now the little Curiosity rover will roll onward, perhaps reaching the base of the yardangs by 2027. We look forward to seeing these jagged formations from a closer point of view!
This is an artist’s concept looking down at Mount Sharp on Mars. The circled area denotes the location of the yardangs, or crags, in the top image. Image via NASA/ JPL-Caltech/ ESA/ DLR/ FU Berlin/ MSSS.
Bottom line: On October 6, 2026, NASA released an image of Martian dawn from the Curiosity rover. The image captures a pale light illuminating distant cliffs and crags.
This image, which the European Southern Observatory (ESO) released on March 27, 2024, shows the supermassive black hole at the center of our Milky Way in polarized light. It depicts the hot material surrounding the black hole. We can’t see the black hole itself at the center. A new study suggests that planets could form in these outer dusty regions. Image via EHT Collaboration/ ESO.
Could black holes have planets? New research says yes, they could.
New simulations suggest massive planets could form in the outer dusty regions around supermassive black holes.
The planets could form through a similar mechanism to how planets form around stars.
Astronomers have found thousands of planets orbiting other stars. They’ve even found some rogue planets, or planets without a star. Now, fascinating new research says more planets could be lurking elsewhere. They could, the study says, be forming around black holes.
Astrophysicists Bhupendra Mishra and Wladimir Lyra discussed the possibility on a SETI livestream on September 21, 2026. They revealed that massive planets could form in the dusty regions around supermassive black holes, similarly to how planets form around stars.
The simulations suggest these planet-mass objects could start around the mass of Jupiter and then keep growing. And, incredibly, a single active black hole could spawn millions of planets at a time.
The new peer-reviewed paper was originally published in The Astrophysical Journal on June 29, 2026.
Scientists think supermassive black holes can be found in the central regions of almost all large galaxies. This study focuses on supermassive black holes that are actively feeding on the gas and dust around them. These incredibly violent objects are known as active galactic nuclei, or AGNs.
When these AGNs pull in matter to devour, the gas and dust start to collect and move around the black hole in a blazingly hot accretion disk. These are similar to the accretion disks that form around stars and create planets.
Noticing this, astrophysicist Barry McKernan — a co-author of the new study — asked Lyra whether the processes that form planets around stars could also occur around an active galactic nucleus.
They found that it could happen, at least theoretically. This is because the same physics should underly the process even in the different environments. If so, black holes could have planets.
The scales are vastly different though. A supermassive black hole could be a million times more massive than the sun. And baby planets forming around it could start out with the mass of Jupiter, our solar system’s biggest planet.
They would also form farther out from the black hole, in the dusty outer region of the disk. That is analogous to the outer region of our solar system, where comets form.
How would planets form?
So just how would one of these massive planets form? The researchers say the process would be similar to the way planets in regular solar systems do: from colliding dust. Dust grains would accumulate in increasingly dense concentrations. That’s the beginning of a baby planet.
Streaming instability — when drag on solid particles within a disk of gas and dust causes them to spontaneously clump — is the process behind this accumulation.
It’s even possible that some of them could grow beyond the planet stage and become brown dwarfs. These “failed stars” are larger than typical planets, but not massive enough to sustain nuclear fusion and shine like stars.
And, incredibly, some of those could keep growing until they became true stars.
How long would they last?
But some black hole planets might face a dire fate. Gravity from the black hole could move some of them inward. The temperatures in that region closer to the black would be far too hot. The planets would disintegrate. This, in turn, would create more dust.
That said, there could be a lot of planets to go round. The researchers estimated that a million planets could form during a single active episode of an active galactic nucleus. One of these bursts is typically about 2 million years long. And a black hole can go through many of these periods in its lifetime. Add that up over billions of years, and the number of planets formed from a black hole could be immense.
View larger. | The accretion disk of dusty material around a black hole could be the birthplace for millions of planets, or planetary-mass objects. Image via NASA/ JPL-Caltech.
Can black hole planets be detected?
Right now, we can’t directly detect any of these planets, if they exist. That will require new methods. The black holes are too massive to use the radial velocity technique, which detects the slight movement of a star caused by an orbiting planet.
The transit method — when a planet passes in front of its star as seen from Earth — might work, but the planets, big as they are, would be vanishingly small compared to the accretion disk of dust around the black hole. And that would be the only background light source available, since the black hole itself doesn’t emit light.
Gravitational microlensing could also work. But you would need several planets around the same black hole to produce a strong enough lensing signal, along with a favorable alignment. In gravitational microlensing, the mass of the planet distorts the spacetime around it, which astronomers can detect.
It would also be difficult to discern a planet from all the other noise that is around a supermassive black hole.
Pretty much the last place in the universe I'd expect to find planets is in the incredibly violent and radiation-laden accretion disks around supermassive black holes.And yet… maybe? ? ?www.scientificamerican.com/article/plan…[thanks to @saavikford.bsky.social for a convo about this]? ?
Even though the underlying physics is similar, these planets still form in a very different environment than those that form around stars. So should we call them planets? The peer-review team for the paper actually objected to calling them planets. So Lyra suggested the term “blanets.”
But that term hasn’t come into use yet, so they are still just calling them planetary-mass objects.
If black holes can have planets orbiting them, then it’s natural to wonder if those objects could have moons. The researchers say that these worlds would be more likely to form as binaries. That is, two bodies of similar mass orbiting each other, rather than one body having a smaller body orbiting it as a moon. There are binary asteroids and minor planets like this in our solar system.
Angular momentum could cause this to happen. When the planets are first forming, angular momentum would produce binary systems in which two objects orbit one another. The same process occurs in the Kuiper Belt in our solar system. In fact, astronomers have discovered a growing number of binary objects there.
What about life?
Could any of these hypothetical planets support life? We don’t know, but it’s not impossible. The simulations suggest that they would have energy, even though black holes don’t emit light like a star. The energy would come from hot gas in the black hole’s accretion disk.
It’s fun to ponder what kind of light might be possible on such worlds. And what would it be like to stand on one of them and look at the glowing accretion disk swirling around the black hole.
Bottom line: New simulations by two astrophysicists suggest that supermassive black holes could have planets orbiting them, much like planets orbit stars.
This image, which the European Southern Observatory (ESO) released on March 27, 2024, shows the supermassive black hole at the center of our Milky Way in polarized light. It depicts the hot material surrounding the black hole. We can’t see the black hole itself at the center. A new study suggests that planets could form in these outer dusty regions. Image via EHT Collaboration/ ESO.
Could black holes have planets? New research says yes, they could.
New simulations suggest massive planets could form in the outer dusty regions around supermassive black holes.
The planets could form through a similar mechanism to how planets form around stars.
Astronomers have found thousands of planets orbiting other stars. They’ve even found some rogue planets, or planets without a star. Now, fascinating new research says more planets could be lurking elsewhere. They could, the study says, be forming around black holes.
Astrophysicists Bhupendra Mishra and Wladimir Lyra discussed the possibility on a SETI livestream on September 21, 2026. They revealed that massive planets could form in the dusty regions around supermassive black holes, similarly to how planets form around stars.
The simulations suggest these planet-mass objects could start around the mass of Jupiter and then keep growing. And, incredibly, a single active black hole could spawn millions of planets at a time.
The new peer-reviewed paper was originally published in The Astrophysical Journal on June 29, 2026.
Scientists think supermassive black holes can be found in the central regions of almost all large galaxies. This study focuses on supermassive black holes that are actively feeding on the gas and dust around them. These incredibly violent objects are known as active galactic nuclei, or AGNs.
When these AGNs pull in matter to devour, the gas and dust start to collect and move around the black hole in a blazingly hot accretion disk. These are similar to the accretion disks that form around stars and create planets.
Noticing this, astrophysicist Barry McKernan — a co-author of the new study — asked Lyra whether the processes that form planets around stars could also occur around an active galactic nucleus.
They found that it could happen, at least theoretically. This is because the same physics should underly the process even in the different environments. If so, black holes could have planets.
The scales are vastly different though. A supermassive black hole could be a million times more massive than the sun. And baby planets forming around it could start out with the mass of Jupiter, our solar system’s biggest planet.
They would also form farther out from the black hole, in the dusty outer region of the disk. That is analogous to the outer region of our solar system, where comets form.
How would planets form?
So just how would one of these massive planets form? The researchers say the process would be similar to the way planets in regular solar systems do: from colliding dust. Dust grains would accumulate in increasingly dense concentrations. That’s the beginning of a baby planet.
Streaming instability — when drag on solid particles within a disk of gas and dust causes them to spontaneously clump — is the process behind this accumulation.
It’s even possible that some of them could grow beyond the planet stage and become brown dwarfs. These “failed stars” are larger than typical planets, but not massive enough to sustain nuclear fusion and shine like stars.
And, incredibly, some of those could keep growing until they became true stars.
How long would they last?
But some black hole planets might face a dire fate. Gravity from the black hole could move some of them inward. The temperatures in that region closer to the black would be far too hot. The planets would disintegrate. This, in turn, would create more dust.
That said, there could be a lot of planets to go round. The researchers estimated that a million planets could form during a single active episode of an active galactic nucleus. One of these bursts is typically about 2 million years long. And a black hole can go through many of these periods in its lifetime. Add that up over billions of years, and the number of planets formed from a black hole could be immense.
View larger. | The accretion disk of dusty material around a black hole could be the birthplace for millions of planets, or planetary-mass objects. Image via NASA/ JPL-Caltech.
Can black hole planets be detected?
Right now, we can’t directly detect any of these planets, if they exist. That will require new methods. The black holes are too massive to use the radial velocity technique, which detects the slight movement of a star caused by an orbiting planet.
The transit method — when a planet passes in front of its star as seen from Earth — might work, but the planets, big as they are, would be vanishingly small compared to the accretion disk of dust around the black hole. And that would be the only background light source available, since the black hole itself doesn’t emit light.
Gravitational microlensing could also work. But you would need several planets around the same black hole to produce a strong enough lensing signal, along with a favorable alignment. In gravitational microlensing, the mass of the planet distorts the spacetime around it, which astronomers can detect.
It would also be difficult to discern a planet from all the other noise that is around a supermassive black hole.
Pretty much the last place in the universe I'd expect to find planets is in the incredibly violent and radiation-laden accretion disks around supermassive black holes.And yet… maybe? ? ?www.scientificamerican.com/article/plan…[thanks to @saavikford.bsky.social for a convo about this]? ?
Even though the underlying physics is similar, these planets still form in a very different environment than those that form around stars. So should we call them planets? The peer-review team for the paper actually objected to calling them planets. So Lyra suggested the term “blanets.”
But that term hasn’t come into use yet, so they are still just calling them planetary-mass objects.
If black holes can have planets orbiting them, then it’s natural to wonder if those objects could have moons. The researchers say that these worlds would be more likely to form as binaries. That is, two bodies of similar mass orbiting each other, rather than one body having a smaller body orbiting it as a moon. There are binary asteroids and minor planets like this in our solar system.
Angular momentum could cause this to happen. When the planets are first forming, angular momentum would produce binary systems in which two objects orbit one another. The same process occurs in the Kuiper Belt in our solar system. In fact, astronomers have discovered a growing number of binary objects there.
What about life?
Could any of these hypothetical planets support life? We don’t know, but it’s not impossible. The simulations suggest that they would have energy, even though black holes don’t emit light like a star. The energy would come from hot gas in the black hole’s accretion disk.
It’s fun to ponder what kind of light might be possible on such worlds. And what would it be like to stand on one of them and look at the glowing accretion disk swirling around the black hole.
Bottom line: New simulations by two astrophysicists suggest that supermassive black holes could have planets orbiting them, much like planets orbit stars.
El Niño could soon trigger coastal flooding along the western coast of North America, through Kelvin waves. But what are Kelvin waves? Image via Connor Scott McManus/ Pexels.
A strong El Niño formed over the summer, and has immediately had an impact on tropical weather.
The Atlantic Ocean has had a below-average hurricane season. In fact, this is the first season in the modern, satellite era to have not recorded a hurricane at this point of the June 1st through November 30th season. Meanwhile, in the Pacific Ocean, the hurricane season has been more active than average with 18 named storms, including nine hurricanes. A typical full hurricane season in the eastern Pacific Ocean normally brings 15 named storms and eight hurricanes.
But El Niño isn’t set to only affect tropical storms. Forecasters are warning that El Niño could now help trigger coastal flooding along the western coast of North America. How? Through the formation of Kelvin waves.
What is a Kelvin wave?
A Kelvin wave is not a wave that crashes along the coast. Instead, it’s a planetary wave that moves from west to east along the equator in a trip that can take up to three months.
While higher than the surface of the water, it doesn’t have a crest like a typical wave. It’s more like a large ripple. Once it arrives in Central and South America, the Kelvin wave continues its journey up the western coast of the Americas. There, it can bring higher water temperatures and water levels, sometimes for months on end.
Kelvin waves were reported to have impacted parts of California back in the spring, but will be more impactful through the fall and winter.
Kelvin waves and El Niño
So, what’s the relationship between El Niño and these Kelvin waves?
El Niño is the warm phase of the global climate pattern called El Niño Southern Oscillation, or ENSO. ENSO has two main phases: El Niño and La Niña, but also a third neutral phase.
El Niño is considered the “warm phase” because that is when the waters of the tropical Pacific Ocean are warmer than average. One reason for the warmer than normal water is due to weaker easterly trade winds, or winds that flow east to west. Weaker trade winds mean the deeper, cold ocean water doesn’t as easily reach the water’s surface, keeping the water warmer.
But the weaker surface winds can also allow the surface layer of the water to propagate back eastward, creating a Kelvin wave. Because this surface layer of the ocean water is warmer than average, it can continue to warm the ocean water. And that includes the temperature of the water off the North American coastline as it moves up.
Kelvin waves can bring warmer waters and higher water levels on the North American West Coast. Image via Yajun Dong/ Pexels.
Strengthening El Niño
El Niño in the Pacific this year is strong. The latest update from NOAA’s Climate Prediction Center says that this current El Niño has a 75% chance of being historically strong, topping the strength of previous El Niño events since 1950, when reliable records began.
This means the likelihood of more significant impacts due to El Niño are much higher. For decades, NOAA scientists have been studying the impact of El Niño on high tide flooding, which is when water covers roads and lower lying areas due to high tide and higher sea levels. They have noticed an increase in high tide flooding during El Niño years.
With sea levels already rising over the decades, Kelvin waves could see coastal communities — especially along the western coast of North America — dealing with more flooding through the fall and winter.
Bottom line: As El Niño continues to strengthen, it could cause Kelvin waves to move east and eventually trigger coastal flooding in the North American west.
El Niño could soon trigger coastal flooding along the western coast of North America, through Kelvin waves. But what are Kelvin waves? Image via Connor Scott McManus/ Pexels.
A strong El Niño formed over the summer, and has immediately had an impact on tropical weather.
The Atlantic Ocean has had a below-average hurricane season. In fact, this is the first season in the modern, satellite era to have not recorded a hurricane at this point of the June 1st through November 30th season. Meanwhile, in the Pacific Ocean, the hurricane season has been more active than average with 18 named storms, including nine hurricanes. A typical full hurricane season in the eastern Pacific Ocean normally brings 15 named storms and eight hurricanes.
But El Niño isn’t set to only affect tropical storms. Forecasters are warning that El Niño could now help trigger coastal flooding along the western coast of North America. How? Through the formation of Kelvin waves.
What is a Kelvin wave?
A Kelvin wave is not a wave that crashes along the coast. Instead, it’s a planetary wave that moves from west to east along the equator in a trip that can take up to three months.
While higher than the surface of the water, it doesn’t have a crest like a typical wave. It’s more like a large ripple. Once it arrives in Central and South America, the Kelvin wave continues its journey up the western coast of the Americas. There, it can bring higher water temperatures and water levels, sometimes for months on end.
Kelvin waves were reported to have impacted parts of California back in the spring, but will be more impactful through the fall and winter.
Kelvin waves and El Niño
So, what’s the relationship between El Niño and these Kelvin waves?
El Niño is the warm phase of the global climate pattern called El Niño Southern Oscillation, or ENSO. ENSO has two main phases: El Niño and La Niña, but also a third neutral phase.
El Niño is considered the “warm phase” because that is when the waters of the tropical Pacific Ocean are warmer than average. One reason for the warmer than normal water is due to weaker easterly trade winds, or winds that flow east to west. Weaker trade winds mean the deeper, cold ocean water doesn’t as easily reach the water’s surface, keeping the water warmer.
But the weaker surface winds can also allow the surface layer of the water to propagate back eastward, creating a Kelvin wave. Because this surface layer of the ocean water is warmer than average, it can continue to warm the ocean water. And that includes the temperature of the water off the North American coastline as it moves up.
Kelvin waves can bring warmer waters and higher water levels on the North American West Coast. Image via Yajun Dong/ Pexels.
Strengthening El Niño
El Niño in the Pacific this year is strong. The latest update from NOAA’s Climate Prediction Center says that this current El Niño has a 75% chance of being historically strong, topping the strength of previous El Niño events since 1950, when reliable records began.
This means the likelihood of more significant impacts due to El Niño are much higher. For decades, NOAA scientists have been studying the impact of El Niño on high tide flooding, which is when water covers roads and lower lying areas due to high tide and higher sea levels. They have noticed an increase in high tide flooding during El Niño years.
With sea levels already rising over the decades, Kelvin waves could see coastal communities — especially along the western coast of North America — dealing with more flooding through the fall and winter.
Bottom line: As El Niño continues to strengthen, it could cause Kelvin waves to move east and eventually trigger coastal flooding in the North American west.
Here’s the technique some people use to find the Andromeda Galaxy aka M31. But be sure you’re looking in a dark sky. Then look northward for the M – or W – shaped constellation Cassiopeia the Queen. Next locate the star Schedar in Cassiopeia. It’s the constellation’s brightest star, and it points to the Andromeda Galaxy. Chart via EarthSky.
The Andromeda Galaxy
The Andromeda Galaxy, aka Messier 31 (M31), is the nearest large spiral galaxy to our Milky Way. It’s wider than our Milky Way and contains more stars. There are perhaps a trillion stars in the Andromeda Galaxy, in contrast to the Milky Way’s 100 billion to 400 billion stars.
And at about 2.5 million light-years away, the Andromeda Galaxy is the farthest object you can see with the unaided eye.
Plus, now is a good time to see it!
Use Cassiopeia to find the Andromeda Galaxy
So tonight, if you have a dark sky, try star-hopping to the Andromeda Galaxy from the constellation Cassiopeia the Queen. If your sky is dark, you might even spot this hazy patch of light with no optical aid, as the ancient stargazers did before the days of city lights.
But what if you aren’t under a dark sky, and you can’t find the Andromeda Galaxy with the eyes alone? Well, some stargazers use binoculars and star-hop to the Andromeda Galaxy via this W- or M-shaped constellation.
During the northern autumn, Cassiopeia appears in the sky above the northeastern horizon at nightfall and early evening, then swings higher in the sky as evening deepens into late night. Then in the wee hours before dawn, Cassiopeia is found high above the northwestern horizon. Note that one half of the W is more deeply notched than the other half. So this deeper V is your “arrow” in the sky, pointing to the Andromeda Galaxy.
Members of the EarthSky community have captured gorgeous images of this neighboring spiral galaxy.
View at EarthSky Community Photos. | Mohammed Abdallah submitted this photo on May 26, 2026, from Egypt and wrote: “Our closest grand spiral neighbor sitting 2.5 million light-years away. The Andromeda Galaxy in all its glory would be 6 times larger than the moon in the night sky with the naked eye if it had the same brightness.” Thank you, Mohammed!View at EarthSky Community Photos. | Vikash Singh captured this image on July 15, 2026, from India. Vikash wrote: “This is the Andromeda Galaxy (M31), captured using the Dwarf 3 smart telescope. The completely clear night sky and low light pollution of Ladakh made it possible to capture incredible details of our neighboring galaxy.” Thank you, Vikash!View at EarthSky Community Photos. | Shaurya Salunkhe in Velhe, Maharashtra, India, used a telephoto lens to capture this view of Messier 31, the Andromeda Galaxy, on January 11, 2026. Shaurya wrote: “I captured the Andromeda Galaxy, the Milky Way’s closest neighbor and the largest galaxy of the Local Group. This is the farthest object that is visible to the unaided eye. It’s approximately 2.5 million light-years away. It’s a fascinating target with stunning colors not to mention the bonus little galaxies (M32 and M110) near it.” Thank you, Shaurya!
Binoculars enhance the view
Binoculars are an excellent choice for beginners to observe the Andromeda Galaxy, because they are so easy to point. As you stand beneath a dark sky, locate the galaxy with your eye first. Then slowly bring the binoculars up to your eyes so that the galaxy comes into binocular view. If that doesn’t work for you, try sweeping the area with your binoculars. Go slowly, and be sure your eyes are dark-adapted. The galaxy will appear as a fuzzy patch to the eye. Naturally, it’ll appear brighter in binoculars. And can you see its central region is brighter and more concentrated?
But remember, with the eye, binoculars, or with a backyard telescope, the Andromeda Galaxy won’t look like the images from famous telescopes and observatories. Still, it will be beautiful. Plus, it’ll take your breath away. And just think, you’re looking at a galaxy over 2 million light-years away. Wow!
Bottom line: You can find the Andromeda Galaxy using the constellation Cassiopeia as a guide. Remember, on a dark night, this galaxy will look like a faint smudge of light. And once you’ve found it with the unaided eye or binoculars, look at it with a telescope if you have one.
Here’s the technique some people use to find the Andromeda Galaxy aka M31. But be sure you’re looking in a dark sky. Then look northward for the M – or W – shaped constellation Cassiopeia the Queen. Next locate the star Schedar in Cassiopeia. It’s the constellation’s brightest star, and it points to the Andromeda Galaxy. Chart via EarthSky.
The Andromeda Galaxy
The Andromeda Galaxy, aka Messier 31 (M31), is the nearest large spiral galaxy to our Milky Way. It’s wider than our Milky Way and contains more stars. There are perhaps a trillion stars in the Andromeda Galaxy, in contrast to the Milky Way’s 100 billion to 400 billion stars.
And at about 2.5 million light-years away, the Andromeda Galaxy is the farthest object you can see with the unaided eye.
Plus, now is a good time to see it!
Use Cassiopeia to find the Andromeda Galaxy
So tonight, if you have a dark sky, try star-hopping to the Andromeda Galaxy from the constellation Cassiopeia the Queen. If your sky is dark, you might even spot this hazy patch of light with no optical aid, as the ancient stargazers did before the days of city lights.
But what if you aren’t under a dark sky, and you can’t find the Andromeda Galaxy with the eyes alone? Well, some stargazers use binoculars and star-hop to the Andromeda Galaxy via this W- or M-shaped constellation.
During the northern autumn, Cassiopeia appears in the sky above the northeastern horizon at nightfall and early evening, then swings higher in the sky as evening deepens into late night. Then in the wee hours before dawn, Cassiopeia is found high above the northwestern horizon. Note that one half of the W is more deeply notched than the other half. So this deeper V is your “arrow” in the sky, pointing to the Andromeda Galaxy.
Members of the EarthSky community have captured gorgeous images of this neighboring spiral galaxy.
View at EarthSky Community Photos. | Mohammed Abdallah submitted this photo on May 26, 2026, from Egypt and wrote: “Our closest grand spiral neighbor sitting 2.5 million light-years away. The Andromeda Galaxy in all its glory would be 6 times larger than the moon in the night sky with the naked eye if it had the same brightness.” Thank you, Mohammed!View at EarthSky Community Photos. | Vikash Singh captured this image on July 15, 2026, from India. Vikash wrote: “This is the Andromeda Galaxy (M31), captured using the Dwarf 3 smart telescope. The completely clear night sky and low light pollution of Ladakh made it possible to capture incredible details of our neighboring galaxy.” Thank you, Vikash!View at EarthSky Community Photos. | Shaurya Salunkhe in Velhe, Maharashtra, India, used a telephoto lens to capture this view of Messier 31, the Andromeda Galaxy, on January 11, 2026. Shaurya wrote: “I captured the Andromeda Galaxy, the Milky Way’s closest neighbor and the largest galaxy of the Local Group. This is the farthest object that is visible to the unaided eye. It’s approximately 2.5 million light-years away. It’s a fascinating target with stunning colors not to mention the bonus little galaxies (M32 and M110) near it.” Thank you, Shaurya!
Binoculars enhance the view
Binoculars are an excellent choice for beginners to observe the Andromeda Galaxy, because they are so easy to point. As you stand beneath a dark sky, locate the galaxy with your eye first. Then slowly bring the binoculars up to your eyes so that the galaxy comes into binocular view. If that doesn’t work for you, try sweeping the area with your binoculars. Go slowly, and be sure your eyes are dark-adapted. The galaxy will appear as a fuzzy patch to the eye. Naturally, it’ll appear brighter in binoculars. And can you see its central region is brighter and more concentrated?
But remember, with the eye, binoculars, or with a backyard telescope, the Andromeda Galaxy won’t look like the images from famous telescopes and observatories. Still, it will be beautiful. Plus, it’ll take your breath away. And just think, you’re looking at a galaxy over 2 million light-years away. Wow!
Bottom line: You can find the Andromeda Galaxy using the constellation Cassiopeia as a guide. Remember, on a dark night, this galaxy will look like a faint smudge of light. And once you’ve found it with the unaided eye or binoculars, look at it with a telescope if you have one.
View at EarthSky Community Photos. | Steven Bellavia in Cherry Springs State Park, Pennsylvania, captured Jupiter half hidden behind the moon on the morning of October 6, 2026. Thank you, Steven! Keep scrolling to see another amazing image from Steven that includes the moons of Jupiter. Then see even more pics from the EarthSky community!
Moon and Jupiter pics here!
On the morning of October 6, 2026, the moon passed in front of the king of the planets, Jupiter, for some observers in most of the U.S., Mexico, southeast Canada, and extending to the southern half of west Africa. Other people were able to see the gas giant planet quite close to the waning moon, making a stunning scene. And EarthSky observers around the world took advantage of the cosmic hide-and-seek photo op, then shared their images with us. Thank you to all who contributed! Here’s a look at our editor’s picks.
View at EarthSky Community Photos. | Steven Bellavia in Cherry Springs State Park, Pennsylvania, captured another shot of Jupiter and our moon, but this one also includes Jupiter’s 4 brightest and largest moons! Great shot! Thanks, Steven.
More pics with Jupiter by the moon
View at EarthSky Community Photos. | Did you see the moon close to one of the visible planets, Jupiter, this morning? From some locations, the moon occulted — passed in front of — the gas giant. That included Quakertown, Pennsylvania, where Karl Diefenderfer captured this shot shortly after Jupiter emerged from behind our natural satellite. You can even see 4 of Jupiter’s own moons if you look closely. Thank you, Karl! View at EarthSky Community Photos. | Wes Inman of Torrington, Connecticut, captured Jupiter as it approached the moon on Tuesday morning. Thank you, Wes!View at EarthSky Community Photos. | Joel Weatherly in Edmonton, Alberta, Canada, captured the moon and Jupiter peeking between the trees on October 6, 2026. Joel wrote: “The moon and Jupiter had a stunning conjunction this morning. I managed to get a brief look at the pair through a gap in the trees.” Thank you, Joel!
More stunning pics
View at EarthSky Community Photos. | Eliot Herman in Tucson, Arizona, captured the moon and Jupiter with its own moons on October 6, 2026. Eliot wrote: “In Arizona, we were out of the occultation zone, but the conjunction 35 minutes after exit was still striking.” Thank you, Eliot!View at EarthSky Community Photos. | Julie Hubbard in Carson, Virginia, called her shot “the moon getting kissed.” Julie wrote: “Out the back door first thing this morning. What a beautiful sight to see!” Thank you, Julie!View at EarthSky Community Photos. | Mario Rana in Hampton, Virginia, captured the moon, Jupiter, and its largest moon Ganymede, on October 6, 2026. Thank you, Mario!
Bottom line: On Tuesday morning, October 6, 2026, the moon slid in front of Jupiter, temporarily blocking it from view. Our EarthSky community members shared their moon and Jupiter pics. See some of them here!
View at EarthSky Community Photos. | Steven Bellavia in Cherry Springs State Park, Pennsylvania, captured Jupiter half hidden behind the moon on the morning of October 6, 2026. Thank you, Steven! Keep scrolling to see another amazing image from Steven that includes the moons of Jupiter. Then see even more pics from the EarthSky community!
Moon and Jupiter pics here!
On the morning of October 6, 2026, the moon passed in front of the king of the planets, Jupiter, for some observers in most of the U.S., Mexico, southeast Canada, and extending to the southern half of west Africa. Other people were able to see the gas giant planet quite close to the waning moon, making a stunning scene. And EarthSky observers around the world took advantage of the cosmic hide-and-seek photo op, then shared their images with us. Thank you to all who contributed! Here’s a look at our editor’s picks.
View at EarthSky Community Photos. | Steven Bellavia in Cherry Springs State Park, Pennsylvania, captured another shot of Jupiter and our moon, but this one also includes Jupiter’s 4 brightest and largest moons! Great shot! Thanks, Steven.
More pics with Jupiter by the moon
View at EarthSky Community Photos. | Did you see the moon close to one of the visible planets, Jupiter, this morning? From some locations, the moon occulted — passed in front of — the gas giant. That included Quakertown, Pennsylvania, where Karl Diefenderfer captured this shot shortly after Jupiter emerged from behind our natural satellite. You can even see 4 of Jupiter’s own moons if you look closely. Thank you, Karl! View at EarthSky Community Photos. | Wes Inman of Torrington, Connecticut, captured Jupiter as it approached the moon on Tuesday morning. Thank you, Wes!View at EarthSky Community Photos. | Joel Weatherly in Edmonton, Alberta, Canada, captured the moon and Jupiter peeking between the trees on October 6, 2026. Joel wrote: “The moon and Jupiter had a stunning conjunction this morning. I managed to get a brief look at the pair through a gap in the trees.” Thank you, Joel!
More stunning pics
View at EarthSky Community Photos. | Eliot Herman in Tucson, Arizona, captured the moon and Jupiter with its own moons on October 6, 2026. Eliot wrote: “In Arizona, we were out of the occultation zone, but the conjunction 35 minutes after exit was still striking.” Thank you, Eliot!View at EarthSky Community Photos. | Julie Hubbard in Carson, Virginia, called her shot “the moon getting kissed.” Julie wrote: “Out the back door first thing this morning. What a beautiful sight to see!” Thank you, Julie!View at EarthSky Community Photos. | Mario Rana in Hampton, Virginia, captured the moon, Jupiter, and its largest moon Ganymede, on October 6, 2026. Thank you, Mario!
Bottom line: On Tuesday morning, October 6, 2026, the moon slid in front of Jupiter, temporarily blocking it from view. Our EarthSky community members shared their moon and Jupiter pics. See some of them here!
When humans began exploring our solar system — the moons, planets, asteroids and comets orbiting our sun — we found not all moons were as cold and inactive as our moon. Here’s a tour of some of our solar system’s most bizarre moons. Images via NASA.
The solar system’s most bizarre moons
Some of the most bizarre worlds in our solar system are moons. That is, they don’t orbit our sun directly, but instead orbit planets, dwarf planets or even asteroids. From icy geysers to endless volcanic eruptions to hidden oceans, these natural satellites have proven much more dynamic than our own dormant moon.
Here’s a quick tour of some of the strangest moons in our solar system.
Orbiting Jupiter, Io is the most volcanically active world in the solar system. Its surface is constantly being reshaped by eruptions that send plumes hundreds of miles into space.
Unlike Earth’s volcanoes, Io’s are driven by tidal heating. That means that Jupiter’s immense gravity stretches and squeezes the little moon. And, as it does so, friction builds up inside, melting rock into magma.
The result is a surface dotted with lava lakes and sulfur deposits. There are no visible impact craters — because eruptions constantly resurface this little world.
View larger. | NASA’s Juno spacecraft captured this detailed view of Jupiter’s moon Io on October 15, 2023. In 2024, Io’s volcanoes were the focus of a study that concludes they are billions of years old, originating from a time when the moon first formed. Image via NASA/ JPL-Caltech/ SwRI/ MSSS/ Ted Stryk.
#2 Europa: An ocean beneath the ice
Another of Jupiter’s moons, Europa, looks smooth and icy on the outside. But beneath that frozen shell lies a global ocean of liquid water. Scientists believe this ocean may contain more water than all of Earth’s oceans combined. Reddish cracks crisscross the surface, likely caused by ice shifting over the ocean below.
Because earthly scientists believe liquid water is a key ingredient for life, Europa is one of the most promising places to search for life in the solar system. Future space missions, including NASA’s Europa Clipper, aim to study this hidden ocean in detail.
This image of Jupiter’s moon Europa is a composite from the Galileo spacecraft. It consists of images acquired in 1995 and 1998. Image via NASA/ JPL-Caltech/ SETI Institute.
#3 Enceladus: Geysers in space
Enceladus blew scientists’ minds when NASA’s Cassini mission discovered jets of water vapor blasting from the south pole of this Saturn moon.
These geysers erupt from an underground ocean, which — in the little moon’s relatively weak gravity — spray material into space. This material feeds Saturn’s E ring! Even more intriguing, the water vapor plumes issuing from Enceladus’ hidden ocean contain complex organic molecules — the building blocks of life.
NASA’s Cassini spacecraft captured this view of Enceladus and its water vapor plumes in 2010. Image via NASA/ JPL/ Space Science Institute/ Freie Universität Berlin.
#4 Titan: Lakes of methane
The largest moon of Saturn is Titan. It’s the only moon in our solar system with a thick atmosphere. Scientists say it has weather, rivers and lakes. But those lakes aren’t filled with water. Instead, they contain liquid methane and ethane.
This hazy, orange world hosts a methane cycle similar to Earth’s water cycle, complete with clouds and rain. Beneath its surface, Titan may also harbor a subsurface ocean of water.
NASA’s Dragonfly mission is currently scheduled to launch in 2028 and arrive at Titan in 2034. Once it lands, the drone-like spacecraft will hop across Titan’s alien landscape.
View larger. | Titan has lakes and seas of liquid methane and ethane on the surface. Ligeia Mare is the 2nd-largest sea on Titan. You can also see rivers in this radar image from the Cassini spacecraft in 2013. Image via NASA.
#5 Mimas: Death Star’s twin
When people see Saturn’s 7th-largest satellite Mimas, they think of the Death Star. The two have a very similar shape, sporting a larger crater in the northern hemisphere that takes up a good deal of territory. In fact, many people think the Death Star was modeled on the moon Mimas.
In reality, the original Star Wars movie came out on May 25, 1977. But we didn’t get a closeup look at Mimas until Voyager 1 passed it in 1980. So, the resemblance is just coincidental.
The crater, named after William Herschel — who discovered the moon as a tiny dot in his telescope — is 86 miles (138 km) across. The terrain shows the entire satellite felt the shockwaves from the impact that created this mighty crater on Mimas.
The most significant feature on Saturn’s moon Mimas is its Herschel crater, which stretches 1/3 of the way across the little moon’s face. It makes the moon resemble the Death Star from Star Wars. Image via NASA’s Cassini spacecraft on its closest-ever flyby of Mimas.
#6 Miranda: A patchwork world
Miranda, a small moon of Uranus, looks like it did shatter … and then reassemble. Its surface is a crazy quilt of textures and ages. It might also be home to the tallest cliff in our solar system. Verona Rupes is a 12-mile (20-km) high scarp.
One theory suggests Miranda broke apart in a massive impact. The pieces then reassembled themselves through gravity into the Frankenstein-like appearance this moon has today.
The Voyager 2 spacecraft took this image of Uranus’ moon Miranda on January 24, 1986. Research shows Miranda might have an ocean beneath its surface. Image via NASA/ JPL-Caltech/ Johns Hopkins.
#7 Triton: A captured rebel
Neptune’s large moon Triton orbits in the direction opposite its planet’s rotation. So it likely didn’t form there, but instead is a captured Kuiper Belt object.
Triton is also geologically active, with nitrogen geysers erupting from its frozen surface. It’s one of the most intriguing — and least explored — moons.
The Webb space telescope captured this wide-field image of Neptune and its rings. The bright blue spot to Neptune’s upper left is the moon Triton. Image via NASA/ ESA/ CSA/ STScI.
Why these bizarre moons matter?
These bizarre moons can help scientists understand how planetary systems evolve. They show the complexity and diversity of distant worlds. Some even provide potential for life far from the sun’s warmth.
Future missions (such as JUICE, Dragonfly and Europa Clipper) will continue to explore these strange satellites, searching for answers to some of the biggest questions in science: How do worlds form? What makes one world habitable and another not? Are we alone?
Bottom line: The solar system’s most bizarre moons reveal active, complex worlds that continue to surprise scientists. Are any of them harboring life?
When humans began exploring our solar system — the moons, planets, asteroids and comets orbiting our sun — we found not all moons were as cold and inactive as our moon. Here’s a tour of some of our solar system’s most bizarre moons. Images via NASA.
The solar system’s most bizarre moons
Some of the most bizarre worlds in our solar system are moons. That is, they don’t orbit our sun directly, but instead orbit planets, dwarf planets or even asteroids. From icy geysers to endless volcanic eruptions to hidden oceans, these natural satellites have proven much more dynamic than our own dormant moon.
Here’s a quick tour of some of the strangest moons in our solar system.
Orbiting Jupiter, Io is the most volcanically active world in the solar system. Its surface is constantly being reshaped by eruptions that send plumes hundreds of miles into space.
Unlike Earth’s volcanoes, Io’s are driven by tidal heating. That means that Jupiter’s immense gravity stretches and squeezes the little moon. And, as it does so, friction builds up inside, melting rock into magma.
The result is a surface dotted with lava lakes and sulfur deposits. There are no visible impact craters — because eruptions constantly resurface this little world.
View larger. | NASA’s Juno spacecraft captured this detailed view of Jupiter’s moon Io on October 15, 2023. In 2024, Io’s volcanoes were the focus of a study that concludes they are billions of years old, originating from a time when the moon first formed. Image via NASA/ JPL-Caltech/ SwRI/ MSSS/ Ted Stryk.
#2 Europa: An ocean beneath the ice
Another of Jupiter’s moons, Europa, looks smooth and icy on the outside. But beneath that frozen shell lies a global ocean of liquid water. Scientists believe this ocean may contain more water than all of Earth’s oceans combined. Reddish cracks crisscross the surface, likely caused by ice shifting over the ocean below.
Because earthly scientists believe liquid water is a key ingredient for life, Europa is one of the most promising places to search for life in the solar system. Future space missions, including NASA’s Europa Clipper, aim to study this hidden ocean in detail.
This image of Jupiter’s moon Europa is a composite from the Galileo spacecraft. It consists of images acquired in 1995 and 1998. Image via NASA/ JPL-Caltech/ SETI Institute.
#3 Enceladus: Geysers in space
Enceladus blew scientists’ minds when NASA’s Cassini mission discovered jets of water vapor blasting from the south pole of this Saturn moon.
These geysers erupt from an underground ocean, which — in the little moon’s relatively weak gravity — spray material into space. This material feeds Saturn’s E ring! Even more intriguing, the water vapor plumes issuing from Enceladus’ hidden ocean contain complex organic molecules — the building blocks of life.
NASA’s Cassini spacecraft captured this view of Enceladus and its water vapor plumes in 2010. Image via NASA/ JPL/ Space Science Institute/ Freie Universität Berlin.
#4 Titan: Lakes of methane
The largest moon of Saturn is Titan. It’s the only moon in our solar system with a thick atmosphere. Scientists say it has weather, rivers and lakes. But those lakes aren’t filled with water. Instead, they contain liquid methane and ethane.
This hazy, orange world hosts a methane cycle similar to Earth’s water cycle, complete with clouds and rain. Beneath its surface, Titan may also harbor a subsurface ocean of water.
NASA’s Dragonfly mission is currently scheduled to launch in 2028 and arrive at Titan in 2034. Once it lands, the drone-like spacecraft will hop across Titan’s alien landscape.
View larger. | Titan has lakes and seas of liquid methane and ethane on the surface. Ligeia Mare is the 2nd-largest sea on Titan. You can also see rivers in this radar image from the Cassini spacecraft in 2013. Image via NASA.
#5 Mimas: Death Star’s twin
When people see Saturn’s 7th-largest satellite Mimas, they think of the Death Star. The two have a very similar shape, sporting a larger crater in the northern hemisphere that takes up a good deal of territory. In fact, many people think the Death Star was modeled on the moon Mimas.
In reality, the original Star Wars movie came out on May 25, 1977. But we didn’t get a closeup look at Mimas until Voyager 1 passed it in 1980. So, the resemblance is just coincidental.
The crater, named after William Herschel — who discovered the moon as a tiny dot in his telescope — is 86 miles (138 km) across. The terrain shows the entire satellite felt the shockwaves from the impact that created this mighty crater on Mimas.
The most significant feature on Saturn’s moon Mimas is its Herschel crater, which stretches 1/3 of the way across the little moon’s face. It makes the moon resemble the Death Star from Star Wars. Image via NASA’s Cassini spacecraft on its closest-ever flyby of Mimas.
#6 Miranda: A patchwork world
Miranda, a small moon of Uranus, looks like it did shatter … and then reassemble. Its surface is a crazy quilt of textures and ages. It might also be home to the tallest cliff in our solar system. Verona Rupes is a 12-mile (20-km) high scarp.
One theory suggests Miranda broke apart in a massive impact. The pieces then reassembled themselves through gravity into the Frankenstein-like appearance this moon has today.
The Voyager 2 spacecraft took this image of Uranus’ moon Miranda on January 24, 1986. Research shows Miranda might have an ocean beneath its surface. Image via NASA/ JPL-Caltech/ Johns Hopkins.
#7 Triton: A captured rebel
Neptune’s large moon Triton orbits in the direction opposite its planet’s rotation. So it likely didn’t form there, but instead is a captured Kuiper Belt object.
Triton is also geologically active, with nitrogen geysers erupting from its frozen surface. It’s one of the most intriguing — and least explored — moons.
The Webb space telescope captured this wide-field image of Neptune and its rings. The bright blue spot to Neptune’s upper left is the moon Triton. Image via NASA/ ESA/ CSA/ STScI.
Why these bizarre moons matter?
These bizarre moons can help scientists understand how planetary systems evolve. They show the complexity and diversity of distant worlds. Some even provide potential for life far from the sun’s warmth.
Future missions (such as JUICE, Dragonfly and Europa Clipper) will continue to explore these strange satellites, searching for answers to some of the biggest questions in science: How do worlds form? What makes one world habitable and another not? Are we alone?
Bottom line: The solar system’s most bizarre moons reveal active, complex worlds that continue to surprise scientists. Are any of them harboring life?
Artist’s impression of the newly discovered rocky exoplanet, LHS 1140b. This exoplanet atmosphere is leaking helium. Could it be a sign of alien life? Image via ESO.
LHS 1140b is a potentially rocky exoplanet in its star’s habitable zone. It’s an intriguing target in the search for worlds that could support life.
Astronomers detected helium escaping from the planet, a possible sign of a long-lasting secondary atmosphere. However, a 2nd observation did not detect helium.
The finding is tentative, but studying LHS 1140b’s atmosphere could help scientists understand how planetary atmospheres form and evolve. And it could show how to recognize signs of life on other worlds.
A helium leak in this exoplanet atmosphere could hint at life
This summer, exoplanet science — the study of planets orbiting stars beyond our sun — took a big step forward.
Reports of helium gas escaping from the atmosphere of LHS 1140b propelled this exoplanet from the pages of scientific journals into the mainstream media.
LHS 1140b orbits a faint red star within the constellation of Cetus — named after a whale-like sea monster in Greek mythology — and just next to the easily recognizable “W” of Cassiopeia. But don’t squint — it appears some 10,000 times fainter than the feeblest star you can see with your unaided eye.
This exoplanet is of particular interest because it is a potentially rocky world within the habitable zone of the star it orbits. This means it may have a temperature that could allow for liquid water on its surface.
Just possibly, it could support the existence of life.
Previous observations of LHS 1140b with the James Webb Space Telescope ruled out the existence of a hydrogen-rich atmosphere, a so-called “primary” atmosphere that is thought to form in step with young planets and is soon lost to space.
Astronomers think that all rocky planets may possess a primary atmosphere and then lose it shortly after they form. This is a short, transient phase in their story.
However, the reported observation of helium may indicate a “secondary” atmosphere, thought to be more stable and long-lived. Secondary atmospheres persist around their planets and can be studied by astronomers.
On planet Earth, our secondary atmosphere has been with us for billions of years. And its chemical balance reflects the combined effects of geology, chemistry and, ultimately, life.
Super-Earth or mini-Neptune?
LHS 1140b orbits a red dwarf star about 1/5 the mass of our sun but some 300 times fainter. However, as viewed from Earth, the star dims with a regular dip every 24.7 days.
From the size of the brightness dip, scientists from the team that discovered the planet in 2017 estimated it to be 1.7 times larger than Earth. Subsequent observations indicated the planet to be just over five times bigger than Earth.
Such super-Earths are among the least massive planets that we can currently detect. And they represent some of the best candidates for detecting life beyond our solar system. But accurately labeling such worlds poses a problem for astronomers.
In our own solar system, the next biggest planet compared to Earth is Uranus, which is equal to 14 Earths. Then comes Neptune at 17 Earth masses.
So is LHS 1140b a super-Earth or a mini-Neptune? We have little idea, mainly because we lack examples of such worlds close to home. This blind spot in our knowledge of planetary physics is a pressing one. That’s because sub-Neptunian worlds appear to be the most common type of planet out there.
A rocky, Earthlike exoplanet with a detectable atmosphere in the habitable zone of even a dim red star would be a major scientific discovery because of the potential for it to host life. However, as with all cutting edge science, the devil is in the details.
A contrast-enhanced color picture of Neptune from the NASA Voyager 2 in 1989. Image via NASA/JPL.
Could LHS 1140b host alien life?
Studying the atmospheres of exoplanets is one of the most exciting areas in modern astronomy. Starting 150 years ago, studies of the outer gaseous envelopes of stars — stellar atmospheres — kick-started the science we today call astrophysics.
In a similar manner, studies of the atmospheres of their planets may lead to an answer to the question: Do they host alien life?
As mentioned, LHS 1140b is of particular interest because it lies within the “habitable zone” of its star. Thus it may have a surface temperature between the 0 C and 100 C (32 and 212 F) and that could allow for the existence of liquid water — and possible life — on its surface.
Care is required with such terms, however. If LHS 1140b absorbs all of the stellar radiation that falls upon it, then it would reach an equilibrium temperature of -30 C (-22 F). That’s seemingly cold but well within the range where the greenhouse effect of a thick atmosphere could warm the planet to more clement temperatures.
However, if we attempt a more realistic mathematical treatment of the planet, then LHS 1140b might be as cold as -90 C (-130 F). That’s comparable to present-day Mars.
A tenuous, nuanced result
This is only the 2nd time that astronomers have captured even a hint of an atmosphere around a remotely Earthlike planet. The 1st time was around the exoplanet Gliese 1214b.
Furthermore, the numbers that underpin the calculations of the surface conditions on LHS1140b involve significant, untested assumptions.
Yet this is progress, however incremental, toward the goal of atmospheric spectroscopy of potentially habitable worlds. And let us not forget that this single step forward was the result of years of dedicated effort from the science team responsible. For that, they deserve recognition, respect and future funding.
A color image of the Earth, showing the Pacific Ocean, from NASA’s Galileo spacecraft in 1990. Image via NASA/JPL.
Nature will teach us the rules
And what of the more lofty goal of detecting life on such worlds from the hints of trace gases in their atmospheres? Which potentially biogenic molecules will offer unambiguous evidence — the so-called “smoking gun” — of life?
Might the answer lie within our own atmosphere, enriched as it is by molecules of oxygen and methane?
My own answer, and perhaps a frustrating one to those impatient for further discovery, is that we will likely have a much clearer picture once we have observed thousands of exoplanet atmospheres, rather than one or two. We need nature to teach us the rules by which planetary atmospheres work and that work has only just begun.
But if a journey of a thousand planets starts with a single step, then with these recent observations of LHS 1140b we have just taken our 2nd. The journey is underway.
Bottom line: A tentative helium detection may offer the first glimpse of this exoplanet atmosphere, but much more evidence is needed to know if LHS 1140b could host life.
Artist’s impression of the newly discovered rocky exoplanet, LHS 1140b. This exoplanet atmosphere is leaking helium. Could it be a sign of alien life? Image via ESO.
LHS 1140b is a potentially rocky exoplanet in its star’s habitable zone. It’s an intriguing target in the search for worlds that could support life.
Astronomers detected helium escaping from the planet, a possible sign of a long-lasting secondary atmosphere. However, a 2nd observation did not detect helium.
The finding is tentative, but studying LHS 1140b’s atmosphere could help scientists understand how planetary atmospheres form and evolve. And it could show how to recognize signs of life on other worlds.
A helium leak in this exoplanet atmosphere could hint at life
This summer, exoplanet science — the study of planets orbiting stars beyond our sun — took a big step forward.
Reports of helium gas escaping from the atmosphere of LHS 1140b propelled this exoplanet from the pages of scientific journals into the mainstream media.
LHS 1140b orbits a faint red star within the constellation of Cetus — named after a whale-like sea monster in Greek mythology — and just next to the easily recognizable “W” of Cassiopeia. But don’t squint — it appears some 10,000 times fainter than the feeblest star you can see with your unaided eye.
This exoplanet is of particular interest because it is a potentially rocky world within the habitable zone of the star it orbits. This means it may have a temperature that could allow for liquid water on its surface.
Just possibly, it could support the existence of life.
Previous observations of LHS 1140b with the James Webb Space Telescope ruled out the existence of a hydrogen-rich atmosphere, a so-called “primary” atmosphere that is thought to form in step with young planets and is soon lost to space.
Astronomers think that all rocky planets may possess a primary atmosphere and then lose it shortly after they form. This is a short, transient phase in their story.
However, the reported observation of helium may indicate a “secondary” atmosphere, thought to be more stable and long-lived. Secondary atmospheres persist around their planets and can be studied by astronomers.
On planet Earth, our secondary atmosphere has been with us for billions of years. And its chemical balance reflects the combined effects of geology, chemistry and, ultimately, life.
Super-Earth or mini-Neptune?
LHS 1140b orbits a red dwarf star about 1/5 the mass of our sun but some 300 times fainter. However, as viewed from Earth, the star dims with a regular dip every 24.7 days.
From the size of the brightness dip, scientists from the team that discovered the planet in 2017 estimated it to be 1.7 times larger than Earth. Subsequent observations indicated the planet to be just over five times bigger than Earth.
Such super-Earths are among the least massive planets that we can currently detect. And they represent some of the best candidates for detecting life beyond our solar system. But accurately labeling such worlds poses a problem for astronomers.
In our own solar system, the next biggest planet compared to Earth is Uranus, which is equal to 14 Earths. Then comes Neptune at 17 Earth masses.
So is LHS 1140b a super-Earth or a mini-Neptune? We have little idea, mainly because we lack examples of such worlds close to home. This blind spot in our knowledge of planetary physics is a pressing one. That’s because sub-Neptunian worlds appear to be the most common type of planet out there.
A rocky, Earthlike exoplanet with a detectable atmosphere in the habitable zone of even a dim red star would be a major scientific discovery because of the potential for it to host life. However, as with all cutting edge science, the devil is in the details.
A contrast-enhanced color picture of Neptune from the NASA Voyager 2 in 1989. Image via NASA/JPL.
Could LHS 1140b host alien life?
Studying the atmospheres of exoplanets is one of the most exciting areas in modern astronomy. Starting 150 years ago, studies of the outer gaseous envelopes of stars — stellar atmospheres — kick-started the science we today call astrophysics.
In a similar manner, studies of the atmospheres of their planets may lead to an answer to the question: Do they host alien life?
As mentioned, LHS 1140b is of particular interest because it lies within the “habitable zone” of its star. Thus it may have a surface temperature between the 0 C and 100 C (32 and 212 F) and that could allow for the existence of liquid water — and possible life — on its surface.
Care is required with such terms, however. If LHS 1140b absorbs all of the stellar radiation that falls upon it, then it would reach an equilibrium temperature of -30 C (-22 F). That’s seemingly cold but well within the range where the greenhouse effect of a thick atmosphere could warm the planet to more clement temperatures.
However, if we attempt a more realistic mathematical treatment of the planet, then LHS 1140b might be as cold as -90 C (-130 F). That’s comparable to present-day Mars.
A tenuous, nuanced result
This is only the 2nd time that astronomers have captured even a hint of an atmosphere around a remotely Earthlike planet. The 1st time was around the exoplanet Gliese 1214b.
Furthermore, the numbers that underpin the calculations of the surface conditions on LHS1140b involve significant, untested assumptions.
Yet this is progress, however incremental, toward the goal of atmospheric spectroscopy of potentially habitable worlds. And let us not forget that this single step forward was the result of years of dedicated effort from the science team responsible. For that, they deserve recognition, respect and future funding.
A color image of the Earth, showing the Pacific Ocean, from NASA’s Galileo spacecraft in 1990. Image via NASA/JPL.
Nature will teach us the rules
And what of the more lofty goal of detecting life on such worlds from the hints of trace gases in their atmospheres? Which potentially biogenic molecules will offer unambiguous evidence — the so-called “smoking gun” — of life?
Might the answer lie within our own atmosphere, enriched as it is by molecules of oxygen and methane?
My own answer, and perhaps a frustrating one to those impatient for further discovery, is that we will likely have a much clearer picture once we have observed thousands of exoplanet atmospheres, rather than one or two. We need nature to teach us the rules by which planetary atmospheres work and that work has only just begun.
But if a journey of a thousand planets starts with a single step, then with these recent observations of LHS 1140b we have just taken our 2nd. The journey is underway.
Bottom line: A tentative helium detection may offer the first glimpse of this exoplanet atmosphere, but much more evidence is needed to know if LHS 1140b could host life.
