Pegasus the Flying Horse is the 7th-largest of the 88 constellations. It’s prominent in the east on autumn evenings in the Northern Hemisphere (spring evenings in the Southern Hemisphere). Find out more in the video above, or on YouTube.
Pegasus the Flying Horse
Pegasus the Flying Horse rises in the east on autumn evenings in the Northern Hemisphere, or spring evenings in the Southern Hemisphere. It’s the 7th-largest of the 88 official constellations, and it dominates the sky with its giant square asterism, fittingly called the Great Square.
The Great Square is huge, covering 20 degrees from top to bottom. That’s the span of two fist-widths held at arm’s length. And that makes Pegasus easy to find. This constellation rises above the eastern horizon at nightfall in early Northern Hemisphere fall, and is nearly overhead at nightfall by the season’s end.
In mythology, Pegasus figured into one of the greatest — and surely the most elaborate — of all sky myths. This one is from ancient Greece, some 3,000 years ago. According to the myth, Pegasus was the flying horse ridden by Perseus the Hero, as he swooped in to save Princess Andromeda from a sea monster. There’s more to the story, which you’ll find in the video at the top of this page.
On autumn evenings in the Northern Hemisphere — spring evenings in the Southern Hemisphere — Pegasus the Flying Horse is ascending in the east in the evening hours. You’ll most easily notice the giant, square-shaped asterism within Pegasus, called the Great Square. Chart via EarthSky.
Stars of Pegasus
As it rises in the evening, the star in the Great Square closest to the horizon is Algenib, with a magnitude of 2.8. It lies 390 light-years away. The star on the opposite corner of the square from Algenib is Scheat, a magnitude 2.4 star lying 199 light-years away. The star to the south in the square is Markab, a magnitude 2.5 star at a distance of 140 light-years. And the final star in the square is Alpheratz. Technically, Alpheratz lies just across the border of Pegasus and is actually a member of the constellation Andromeda. Alpheratz is the brightest of the four stars at magnitude 2.1 and lies 97 light-years away.
The Great Square marks the body of the flying horse. Trails leading off the west side of the square mark the front legs and head of Pegasus. Extending out from Markab, two stars at magnitude 3.4 and 3.5, Homam and Biham, lead the way to the head star, magnitude 2.4 star Enif. This star is helpful in finding the globular cluster Messier 15 (M15).
Find the forelegs of Pegasus off of Scheat. Five degrees west of Scheat is 3rd-magnitude star Matar. As the brightest leg star in Pegasus, it’s helpful in finding a couple of notable galaxies.
Pegasus the Flying Horse is a giant constellation that rises in the east on October evenings. Image via Stellarium.
The Great Square is an asterism, or a group of stars that isn’t itself a constellation but is easy to recognize.
View at EarthSky Community Photos. | Prateek Pandey in Bhopal, India, captured this photo of Pegasus. He wrote: “Pegasus is named after the winged horse in Greek mythology. Curiously, the constellation Pegasus only represents the top half of the horse. In some depictions, the horse is shown rising out of the water. Viewed best in autumn, turn your eyes to the east as the night falls, and see the winged horse rising high up in the sky.” Thank you, Prateek!
Using Pegasus to find the Andromeda Galaxy
Pegasus is close to the constellation Andromeda, so it’s useful for star-hopping to the Andromeda galaxy. You’ll need a dark-sky site to track down Andromeda without optical aid. It’s much easier to spot with binoculars or a telescope. Follow this link for more information on how to use Pegasus to find Andromeda.
Find the Andromeda Galaxy (M31) by star-hopping from the Great Square of Pegasus. Chart via EarthSky.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!
Stephan’s Quintet
Pegasus is home to many galaxy clusters. The most famous is probably Stephan’s Quintet, a favorite target among astrophotographers. This tight gathering of five galaxies has a faint magnitude of 13.6. The largest and brightest, NGC 7320, has a small redshift compared to the other four, revealing that it is probably not a physical member of the group and just a line-of-sight coincidence.
Fun fact: In the 1946 movie It’s a Wonderful Life, angels in heaven discussing George Bailey are depicted as the galaxies in Stephan’s Quintet.
View at EarthSky Community Photos. | Andy Dungan near Cotopaxi, Colorado, captured two galaxy groups, namely Stephan’s Quintet and the Deer Lick Group, both in the constellation Pegasus, on October 27, 2024. Andy wrote: “Over the years I have run into pictures and discussions of these two objects. Both are rather small and close together. Their data and histories are fun too. What fun it is exploring the universe.” Thank you, Andy!This image of Stephan’s Quintet is from 2009, courtesy of the Hubble Space Telescope. Image via Wikimedia Commons/ NASA/ ESA/ Hubble SM4 ERO Team.
Other galaxies in Pegasus the Flying Horse
Three other notable galaxy clusters lie in Pegasus. The brightest is magnitude 9.5 and is just half a degree from Stephan’s Quintet. The cluster has the curious name Deer Lick Group. Follow Scheat to Matar and then about 4.5 degrees farther and slightly north of the direction you were heading. This will bring you to the Deer Lick Group, NGC 7331. Here you’ll find one large spiral galaxy and a spattering of smaller ones.
The Deer Lick Group contains one large spiral galaxy and other smaller galaxies. It lies in the constellation Pegasus. Image via W4sm astro/ Wikimedia Commons.
The Pegasus I Cluster lies on the southern edge of the constellation not far from the circlet of Pisces. At a distance of 8 degrees from Markab on the sky’s dome, the Pegasus I Cluster is a grouping with a magnitude of 11.1. The galaxy cluster requires a large telescope to see or a long-exposure photograph, but it reveals a beautiful and striking number of galaxies.
The Pegasus II Cluster lies back within the square of Pegasus. Halfway between Alpheratz and Scheat, it lies just inside the border of a line that would be drawn connecting these two stars. A bit dimmer at magnitude 12.6, the Pegasus II Cluster (NGC 7720) is a powerful radio source, the target of much scientific study.
Globular Cluster M15 in Pegasus the Flying Horse
One other deep-sky object of note in Pegasus is the globular cluster Messier 15 (M15). You can find M15 easily using the head and neck stars of Pegasus. Start with the star Markab and go to the two dimmer stars that mark the neck. From the last star of the neck (Biham) to the brighter head star Enif, continue a line straight out for a little more than 4 degrees. Here you will find the magnitude 6.4 globular cluster M15. It lies about 33,600 light-years away and will show up nicely in a pair of binoculars.
Astronomers discovered the first exoplanet orbiting a sun-like star in the constellation Pegasus. They named the planet 51 Pegasi b after the star it orbits. Didier Queloz and Michel Mayor discovered the planet in 1995 and received the Nobel Prize in Physics for their discovery in 2019.
Artist’s concept of the hot Jupiter exoplanet 51 Pegasi b. The first exoplanet discovered around a sun-like star, 51 Pegasi b lies about 50 light-years from Earth in the constellation Pegasus the Flying Horse. Image via ESO/ M. Kornmesser/ Nick Risinger/ Wikimedia Commons.
Bottom line: Pegasus the Flying Horse is a giant constellation that dominates the skies in Northern Hemisphere fall. The constellation contains a famous asterism called the Great Square.
Pegasus the Flying Horse is the 7th-largest of the 88 constellations. It’s prominent in the east on autumn evenings in the Northern Hemisphere (spring evenings in the Southern Hemisphere). Find out more in the video above, or on YouTube.
Pegasus the Flying Horse
Pegasus the Flying Horse rises in the east on autumn evenings in the Northern Hemisphere, or spring evenings in the Southern Hemisphere. It’s the 7th-largest of the 88 official constellations, and it dominates the sky with its giant square asterism, fittingly called the Great Square.
The Great Square is huge, covering 20 degrees from top to bottom. That’s the span of two fist-widths held at arm’s length. And that makes Pegasus easy to find. This constellation rises above the eastern horizon at nightfall in early Northern Hemisphere fall, and is nearly overhead at nightfall by the season’s end.
In mythology, Pegasus figured into one of the greatest — and surely the most elaborate — of all sky myths. This one is from ancient Greece, some 3,000 years ago. According to the myth, Pegasus was the flying horse ridden by Perseus the Hero, as he swooped in to save Princess Andromeda from a sea monster. There’s more to the story, which you’ll find in the video at the top of this page.
On autumn evenings in the Northern Hemisphere — spring evenings in the Southern Hemisphere — Pegasus the Flying Horse is ascending in the east in the evening hours. You’ll most easily notice the giant, square-shaped asterism within Pegasus, called the Great Square. Chart via EarthSky.
Stars of Pegasus
As it rises in the evening, the star in the Great Square closest to the horizon is Algenib, with a magnitude of 2.8. It lies 390 light-years away. The star on the opposite corner of the square from Algenib is Scheat, a magnitude 2.4 star lying 199 light-years away. The star to the south in the square is Markab, a magnitude 2.5 star at a distance of 140 light-years. And the final star in the square is Alpheratz. Technically, Alpheratz lies just across the border of Pegasus and is actually a member of the constellation Andromeda. Alpheratz is the brightest of the four stars at magnitude 2.1 and lies 97 light-years away.
The Great Square marks the body of the flying horse. Trails leading off the west side of the square mark the front legs and head of Pegasus. Extending out from Markab, two stars at magnitude 3.4 and 3.5, Homam and Biham, lead the way to the head star, magnitude 2.4 star Enif. This star is helpful in finding the globular cluster Messier 15 (M15).
Find the forelegs of Pegasus off of Scheat. Five degrees west of Scheat is 3rd-magnitude star Matar. As the brightest leg star in Pegasus, it’s helpful in finding a couple of notable galaxies.
Pegasus the Flying Horse is a giant constellation that rises in the east on October evenings. Image via Stellarium.
The Great Square is an asterism, or a group of stars that isn’t itself a constellation but is easy to recognize.
View at EarthSky Community Photos. | Prateek Pandey in Bhopal, India, captured this photo of Pegasus. He wrote: “Pegasus is named after the winged horse in Greek mythology. Curiously, the constellation Pegasus only represents the top half of the horse. In some depictions, the horse is shown rising out of the water. Viewed best in autumn, turn your eyes to the east as the night falls, and see the winged horse rising high up in the sky.” Thank you, Prateek!
Using Pegasus to find the Andromeda Galaxy
Pegasus is close to the constellation Andromeda, so it’s useful for star-hopping to the Andromeda galaxy. You’ll need a dark-sky site to track down Andromeda without optical aid. It’s much easier to spot with binoculars or a telescope. Follow this link for more information on how to use Pegasus to find Andromeda.
Find the Andromeda Galaxy (M31) by star-hopping from the Great Square of Pegasus. Chart via EarthSky.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!
Stephan’s Quintet
Pegasus is home to many galaxy clusters. The most famous is probably Stephan’s Quintet, a favorite target among astrophotographers. This tight gathering of five galaxies has a faint magnitude of 13.6. The largest and brightest, NGC 7320, has a small redshift compared to the other four, revealing that it is probably not a physical member of the group and just a line-of-sight coincidence.
Fun fact: In the 1946 movie It’s a Wonderful Life, angels in heaven discussing George Bailey are depicted as the galaxies in Stephan’s Quintet.
View at EarthSky Community Photos. | Andy Dungan near Cotopaxi, Colorado, captured two galaxy groups, namely Stephan’s Quintet and the Deer Lick Group, both in the constellation Pegasus, on October 27, 2024. Andy wrote: “Over the years I have run into pictures and discussions of these two objects. Both are rather small and close together. Their data and histories are fun too. What fun it is exploring the universe.” Thank you, Andy!This image of Stephan’s Quintet is from 2009, courtesy of the Hubble Space Telescope. Image via Wikimedia Commons/ NASA/ ESA/ Hubble SM4 ERO Team.
Other galaxies in Pegasus the Flying Horse
Three other notable galaxy clusters lie in Pegasus. The brightest is magnitude 9.5 and is just half a degree from Stephan’s Quintet. The cluster has the curious name Deer Lick Group. Follow Scheat to Matar and then about 4.5 degrees farther and slightly north of the direction you were heading. This will bring you to the Deer Lick Group, NGC 7331. Here you’ll find one large spiral galaxy and a spattering of smaller ones.
The Deer Lick Group contains one large spiral galaxy and other smaller galaxies. It lies in the constellation Pegasus. Image via W4sm astro/ Wikimedia Commons.
The Pegasus I Cluster lies on the southern edge of the constellation not far from the circlet of Pisces. At a distance of 8 degrees from Markab on the sky’s dome, the Pegasus I Cluster is a grouping with a magnitude of 11.1. The galaxy cluster requires a large telescope to see or a long-exposure photograph, but it reveals a beautiful and striking number of galaxies.
The Pegasus II Cluster lies back within the square of Pegasus. Halfway between Alpheratz and Scheat, it lies just inside the border of a line that would be drawn connecting these two stars. A bit dimmer at magnitude 12.6, the Pegasus II Cluster (NGC 7720) is a powerful radio source, the target of much scientific study.
Globular Cluster M15 in Pegasus the Flying Horse
One other deep-sky object of note in Pegasus is the globular cluster Messier 15 (M15). You can find M15 easily using the head and neck stars of Pegasus. Start with the star Markab and go to the two dimmer stars that mark the neck. From the last star of the neck (Biham) to the brighter head star Enif, continue a line straight out for a little more than 4 degrees. Here you will find the magnitude 6.4 globular cluster M15. It lies about 33,600 light-years away and will show up nicely in a pair of binoculars.
Astronomers discovered the first exoplanet orbiting a sun-like star in the constellation Pegasus. They named the planet 51 Pegasi b after the star it orbits. Didier Queloz and Michel Mayor discovered the planet in 1995 and received the Nobel Prize in Physics for their discovery in 2019.
Artist’s concept of the hot Jupiter exoplanet 51 Pegasi b. The first exoplanet discovered around a sun-like star, 51 Pegasi b lies about 50 light-years from Earth in the constellation Pegasus the Flying Horse. Image via ESO/ M. Kornmesser/ Nick Risinger/ Wikimedia Commons.
Bottom line: Pegasus the Flying Horse is a giant constellation that dominates the skies in Northern Hemisphere fall. The constellation contains a famous asterism called the Great Square.
The 4 participants in NASA’s Crew Health and Performance Exploration Analog (CHAPEA), or Mars habitat simulation, emerged after 1 year inside. The crew members are, from left to right, Matthew Montgomery, James Spicer, Ross Elder and Ellen Ellis. Image via NASA.
Yearlong Mars habitat test is now complete
On October 19, 2025, four crew members entered a simulated Mars habitat that NASA calls the Crew Health and Performance Exploration Analog (CHAPEA). And after 378 days, the four crew members — Ross Elder, commander; Ellen Ellis, medical officer; Matthew Montgomery, science officer; and James Spicer, flight engineer — emerged from the 3D printed habitat in Houston on October 31, 2026.
The goal was to learn how a crew could live in isolation and face some of the challenges of a Mars mission. The crew had to grow their own crops, maintain their health and work together, including some simulated Marswalks.
Part of the test was to have delayed communication with “Earth”. These delays ranged from 26 to 44 minutes. Messages back and forth from Mars won’t be instantaneous, so it was important for NASA to learn how people can cope when they can’t immediately ask for advice.
Early takeaways from the experiment
The crew members said that while future Mars astronauts will need to be skilled at fixing things themselves, the real challenge will be the psychological ones. They said the inside of the habitat was unusually quiet. They also had limited opportunities for personal time. The work-rest-personal life balance could be a challenge on Mars.
For the next two weeks, the crew will undergo post-mission evaluations and debriefing.
Michael Stenger, chief scientist for NASA’s Human Research Program, said:
This mission has been incredibly valuable in starting to teach us how to understand requirements for year-long missions, including medical and psychological care, via communication delays. When combining this Mars-realistic mission analog with a suite of physiological, psychological, and performance measures in a rigorously controlled environment, we’ll be able to translate the knowledge from these experiences to Moon Base and beyond.
You can watch a replay of their exit from the habitat here.
The Mars habitat simulation
Back in 2023, NASA unveiled its simulation of a Mars habitat. This has been the second of three planned habitat simulations. The habitat is at Johnson Space Center in Houston.
During the past year, the volunteers have tested out the technology, even as they themselves are tested.
The Mars-surface simulation is part of NASA’s program named Crew Health and Performance Exploration Analog (CHAPEA). It’s an experiment to test human preparedness for visiting the red planet. Currently, the Artemis mission is working on returning humans to the moon.
And NASA plans to use that technology to eventually send humans a step further … to Mars. NASA’s stated goal for the Artemis missions is to:
… establish a sustainable presence on the moon to prepare for human missions to Mars.
But are humans ready to go to Mars?
On October 31, 2026, NASA’s 2nd crew left its Mars Habitat, named Crew Health and Performance Exploration Analog (CHAPEA), after a year in isolation. Image via NASA.
Mars habitat simulation is a test
The four volunteers are not astronauts. But they are trained to simulate situations that might occur on Mars, such as habitat maintenance, robotic operations and ‘Marswalks’. Some of the ‘Marswalks’ – or spacewalks on Mars – involved geology, building and exploration.
Additionally, the crew will also faced realistic stressful situations, which included resource limitations and equipment failure. For example, they had to manage with a limited amount of water as they grew their own vegetables and tackled personal hygiene.
In addition, the volunteers had to endure isolation and confinement during their year in CHAPEA. Meanwhile, scientists monitored their mental health and the social dynamics of the foursome.
Habitat construction
In the video below, you can see the giant 3D printer as it assembles the habitat.
This video shows how NASA used 3D printing to construct a simulated Mars habitat for testing. Video via NASA.
Bottom line: On October 31, 2026, four participants in NASA’s Mars habitat simulation emerged after one year of testing and training for what astronauts might encounter when they someday visit Mars.
The 4 participants in NASA’s Crew Health and Performance Exploration Analog (CHAPEA), or Mars habitat simulation, emerged after 1 year inside. The crew members are, from left to right, Matthew Montgomery, James Spicer, Ross Elder and Ellen Ellis. Image via NASA.
Yearlong Mars habitat test is now complete
On October 19, 2025, four crew members entered a simulated Mars habitat that NASA calls the Crew Health and Performance Exploration Analog (CHAPEA). And after 378 days, the four crew members — Ross Elder, commander; Ellen Ellis, medical officer; Matthew Montgomery, science officer; and James Spicer, flight engineer — emerged from the 3D printed habitat in Houston on October 31, 2026.
The goal was to learn how a crew could live in isolation and face some of the challenges of a Mars mission. The crew had to grow their own crops, maintain their health and work together, including some simulated Marswalks.
Part of the test was to have delayed communication with “Earth”. These delays ranged from 26 to 44 minutes. Messages back and forth from Mars won’t be instantaneous, so it was important for NASA to learn how people can cope when they can’t immediately ask for advice.
Early takeaways from the experiment
The crew members said that while future Mars astronauts will need to be skilled at fixing things themselves, the real challenge will be the psychological ones. They said the inside of the habitat was unusually quiet. They also had limited opportunities for personal time. The work-rest-personal life balance could be a challenge on Mars.
For the next two weeks, the crew will undergo post-mission evaluations and debriefing.
Michael Stenger, chief scientist for NASA’s Human Research Program, said:
This mission has been incredibly valuable in starting to teach us how to understand requirements for year-long missions, including medical and psychological care, via communication delays. When combining this Mars-realistic mission analog with a suite of physiological, psychological, and performance measures in a rigorously controlled environment, we’ll be able to translate the knowledge from these experiences to Moon Base and beyond.
You can watch a replay of their exit from the habitat here.
The Mars habitat simulation
Back in 2023, NASA unveiled its simulation of a Mars habitat. This has been the second of three planned habitat simulations. The habitat is at Johnson Space Center in Houston.
During the past year, the volunteers have tested out the technology, even as they themselves are tested.
The Mars-surface simulation is part of NASA’s program named Crew Health and Performance Exploration Analog (CHAPEA). It’s an experiment to test human preparedness for visiting the red planet. Currently, the Artemis mission is working on returning humans to the moon.
And NASA plans to use that technology to eventually send humans a step further … to Mars. NASA’s stated goal for the Artemis missions is to:
… establish a sustainable presence on the moon to prepare for human missions to Mars.
But are humans ready to go to Mars?
On October 31, 2026, NASA’s 2nd crew left its Mars Habitat, named Crew Health and Performance Exploration Analog (CHAPEA), after a year in isolation. Image via NASA.
Mars habitat simulation is a test
The four volunteers are not astronauts. But they are trained to simulate situations that might occur on Mars, such as habitat maintenance, robotic operations and ‘Marswalks’. Some of the ‘Marswalks’ – or spacewalks on Mars – involved geology, building and exploration.
Additionally, the crew will also faced realistic stressful situations, which included resource limitations and equipment failure. For example, they had to manage with a limited amount of water as they grew their own vegetables and tackled personal hygiene.
In addition, the volunteers had to endure isolation and confinement during their year in CHAPEA. Meanwhile, scientists monitored their mental health and the social dynamics of the foursome.
Habitat construction
In the video below, you can see the giant 3D printer as it assembles the habitat.
This video shows how NASA used 3D printing to construct a simulated Mars habitat for testing. Video via NASA.
Bottom line: On October 31, 2026, four participants in NASA’s Mars habitat simulation emerged after one year of testing and training for what astronauts might encounter when they someday visit Mars.
The Blaze Star isn’t 1 star but 2. It’s a binary system with a white dwarf and a red giant, located about 3,000 light-years from Earth. The Blaze Star’s white dwarf has built up material on its surface, siphoned off from the red giant star. Periodically, it can’t take no more and explodes. That should happen about every 80 years. But the Blaze Star has been keeping us waiting. Astronomers say neutrinos might provide an early warning. Image via NASA Goddard Scientific Visualization Studio.
The now-infamous Blaze Star — also known as T Coronae Borealis or “T Cor Bor” (T CrB) — is late. This object is a recurring nova, a type of binary star system that undergoes explosive thermonuclear explosions multiple times over humanly observable timescales (typically every few decades to once a century). It last erupted in 1946. And scientists expected another outburst as early as 2024.
But so far no luck.
While they’re waiting, researchers have been exploring whether the elusive, fundamental, subatomic particles known as neutrinos might provide an early warning of the Blaze Star’s coming eruption. When it finally erupts, the Blaze Star might become briefly bright enough to see with the unaided eye, perhaps as bright as the brightest star in the constellation Corona Borealis, called Gemma or Alphecca.
But before those photons reach our eyes, scientists say, neutrinos could reach Earth first.
Want to see the Blaze Star go nova? We do, too! The constellation Corona Borealis, aka the Northern Crown, will be the site of the nova. In this animation, X marks the spot! Image via Chris Harvey/ Stellarium.
Could neutrinos provide an early warning?
On April 14, 2026, researchers published a study in The Astrophysical Journal Letters that first suggested neutrinos as a possible early warning of the Blaze Star’s next nova.
The research explores how the Blaze Star might produce high-energy particles during its next eruption. Neutrinos rarely interact with matter, so they can escape dense regions that trap other signals. That makes them useful messengers from violent events in space. The scientists modeled two possible ways that particles could gain energy, through shock waves or changes in magnetic fields.
The shock wave method. Material blasted from the white dwarf crashes into surrounding gas. The collisions could produce high-energy gamma rays and neutrinos.
The magnetic field method. It involves what’s called magnetic reconnection, a fundamental astrophysical process taking place in the highly conductive plasma of a star — its superheated matter. Magnetic reconnection is when magnetic field lines abruptly break, rearrange and reconnect. In this scenario, tangled magnetic fields would release energy, accelerating particles near the white dwarf. The dense material surrounding the white dwarf might trap gamma rays, while neutrinos escape and travel toward Earth.
The researchers also studied another recurring nova, RS Ophiuchi, which erupted in 2021. They used those observations to help predict what might happen when the Blaze Star erupts.
The researchers found that neutrinos in the magnetic reconnection model could reach Earth about 9 to 10 hours earlier than photons or gamma rays. The early neutrinos could give astronomers a head start on pointing their telescopes. It could also help them determine the mechanism of what is happening in the Blaze Star system during the eruption.
By the way, because neutrinos carry no electrical charge and almost never interact with matter, they cannot be detected directly. Instead, scientists detect them by looking for the charged particles or flashes of light produced when a neutrino occasionally collides with an atom. Look here for details on neutrino detection methods.
Seeing the Blaze Star — Northern Hemisphere
Corona Borealis is almost, but not quite, circumpolar from mid-northern latitudes. So it’s not visible all year round for most northern observers, but it is up much of the year. Northern spring is the best time to start looking for this easy-to-find constellation. In northern fall, look low in the west-northwest.
No matter where you are on the globe, the constellation looks like a letter C. You’ll find Corona Borealis approximately on a line between the bright stars Arcturus and Vega. And Corona Borealis is next to another famous star pattern for those with dark skies. It’s the squarish 4-star pattern of the Keystone in Hercules the Strongman.
Did you hear those words dark sky? You can see the bright stars Arcturus and Vega from inside cities. But you’ll need a dark sky to pick out the Keystone and Corona Borealis. Visit EarthSky’s Best Places to Stargaze.
Do you need binoculars? No. You don’t need them. But binoculars are always a good idea.
Find the bright stars Vega and Arcturus. The famous squarish pattern of the Keystone in the constellation Hercules is between them. And so is an easy-to-see semicircle of stars, the constellation Corona Borealis. The Blaze Star will erupt within Corona Borealis. It’ll be about as bright as Corona Borealis’ brightest star, Alphecca. Image via NASA.
We all live under the same sky. But Earth’s Northern and Southern Hemispheres see the sky from different perspectives.
And remember how we said that Corona Borealis was almost — but not quite — circumpolar for the Northern Hemisphere? That means it’s far to the north on the sky’s dome. From deep in the Southern Hemisphere — for example, the latitude of New Zealand and southern Australia — Corona Borealis rises to only around 20 to 25 degrees above the northern horizon at its highest. So, in addition to a dark sky, you’ll also want a clear view to the north.
Look north to northeast for a delicate semicircle or backward C shape of stars between the bright orange star Arcturus and the bright blue-white star Vega. The famous Keystone pattern in Hercules is also between these two, right next to Corona Borealis.
T Coronae Borealis — called “T Cor Bor” by many — is located about 3,000 light-years from Earth. It’s a double star system, consisting of a large cool star and a smaller hot star, which orbit each other every 228 days.
This system is what’s called a recurring nova. It’s not a supernova or star that blows itself to bits. Novas operate differently from supernovas. They survive to brighten again. T Cor Bor has outbursts about every 80 years.
Its last outburst was in 1946. That’s why astronomers believe another outburst will occur soon.
What makes the nova erupt? The cool star in the T Corona Borealis system is a swollen red giant. It continually transfers material to its companion in the system, the hot star. The hot star is a white dwarf, surrounded by an accretion disk made of material transferred over from the other star.
All of this is hidden inside a dense cloud of material from the red giant. When the system is quiescent, the red giant dominates the visible light output of the entire system. So the system appears as an M3 giant.
But during outbursts, the transfer of material from the red giant to the hot white dwarf increases greatly. The hot star then expands. And the luminosity of the system increases. Voila. We have a nova.
View larger. Here’s the location of T Corona Borealis, on a more detailed chart used by variable star observers. Image via the American Association of Variable Star Observers (AAVSO).
Why hasn’t the Blaze Star blazed?
Astronomers have been waiting several years for the Blaze Star to erupt. One recent prediction came from Jean Schneider of the Paris Observatory, publishing in the Research Notes of the American Astronomical Society in October 2024.
He pinpointed possible dates of March 27, 2025, and November 10, 2025. Those dates have come and gone with no big kablooey.
Schneider came to his possible dates using a combination of the previous eruption dates and the orbital data of the binary system. But Schneider admits in his paper that no one can exactly predict the eruption.
And, clearly, predicting eruptions of stars isn’t an exact science. The Blaze Star underwent two known eruptions recorded by astronomers. Those events were on May 12, 1866, and on February 9, 1946. Those eruptions were 80 years apart. So scientists thought that, in another 80 years, the star would erupt again. Eighty years from 1946 would be 2026.
And still we wait …
Artist’s concept of a red giant star and white dwarf star. A stream of material flows from the red giant to the white dwarf, eventually causing a runaway thermonuclear reaction on the white dwarf that will appear as a new star, or nova, in earthly skies. The constellation Corona Borealis the Northern Crown should have a nova appear from the Blaze Star approximately every 80 years. Image via NASA/ Goddard Space Flight Center.
How bright will the Blaze Star be?
How bright will it get in our sky? Astronomers expect it to reach an apparent magnitude of 2. That’s a respectable brightness for a star. It’s conveniently comparable to the brightest star in the Northern Crown, the Jewel of the Crown, Alphecca. So, for a few days, the Northern Crown will have two jewels!
T Corona Borealis — the Blaze Star — is also one of the most distant stars you’ll ever see. Alphecca is around 75 light-years away, while the Blaze Star is 3,000 light-years away.
So that gives you some perspective on the absolute magnitude (brightness) of this enormous blast. The actual explosion of the Blaze Star nova will likely dwarf any explosion you’ll ever see. But the star is far away. This explosion has traveled 3,000 years to get here. So, in relative terms, the nova will have happened during the Bronze Age.
Remember when viewing Alphecca and T Corona Borealis side-by-side with approximately the same brightness, the nova is 40 times farther away than Alphecca. Also, we are not seeing the two stars at the same moment in time. One we see as it was 75 years ago. And the other we see as it was 3,000 years ago. It can be hard to get your head around that!
The nova will brighten the star by thousands of times, typically over just a few hours, and then take some days to fade away again. When it’s done, it will go back to its normal appearance … which means we won’t be able to see it anymore, with the eye alone.
So erupt already!
View at EarthSky Community Photos. | Paul Henkiel of Flagstaff, Arizona, captured this image on April 30, 2024. It’s the easy-to-spot C-shaped constellation Corona Borealis the Northern Crown. The brightest star here is Alphecca, aka Gemma, sometimes called the Jewel of the Crown. When the Blaze Star erupts, it’ll be approximately as bright as Alphecca. The Northern Crown will have 2 jewels! Thank you, Paul!
Bottom line: Astronomers are still waiting for the Blaze Star, T Coronae Borealis, to erupt. New research suggests neutrinos could provide an early warning of its next outburst. Here’s how to find it in the sky.
The Blaze Star isn’t 1 star but 2. It’s a binary system with a white dwarf and a red giant, located about 3,000 light-years from Earth. The Blaze Star’s white dwarf has built up material on its surface, siphoned off from the red giant star. Periodically, it can’t take no more and explodes. That should happen about every 80 years. But the Blaze Star has been keeping us waiting. Astronomers say neutrinos might provide an early warning. Image via NASA Goddard Scientific Visualization Studio.
The now-infamous Blaze Star — also known as T Coronae Borealis or “T Cor Bor” (T CrB) — is late. This object is a recurring nova, a type of binary star system that undergoes explosive thermonuclear explosions multiple times over humanly observable timescales (typically every few decades to once a century). It last erupted in 1946. And scientists expected another outburst as early as 2024.
But so far no luck.
While they’re waiting, researchers have been exploring whether the elusive, fundamental, subatomic particles known as neutrinos might provide an early warning of the Blaze Star’s coming eruption. When it finally erupts, the Blaze Star might become briefly bright enough to see with the unaided eye, perhaps as bright as the brightest star in the constellation Corona Borealis, called Gemma or Alphecca.
But before those photons reach our eyes, scientists say, neutrinos could reach Earth first.
Want to see the Blaze Star go nova? We do, too! The constellation Corona Borealis, aka the Northern Crown, will be the site of the nova. In this animation, X marks the spot! Image via Chris Harvey/ Stellarium.
Could neutrinos provide an early warning?
On April 14, 2026, researchers published a study in The Astrophysical Journal Letters that first suggested neutrinos as a possible early warning of the Blaze Star’s next nova.
The research explores how the Blaze Star might produce high-energy particles during its next eruption. Neutrinos rarely interact with matter, so they can escape dense regions that trap other signals. That makes them useful messengers from violent events in space. The scientists modeled two possible ways that particles could gain energy, through shock waves or changes in magnetic fields.
The shock wave method. Material blasted from the white dwarf crashes into surrounding gas. The collisions could produce high-energy gamma rays and neutrinos.
The magnetic field method. It involves what’s called magnetic reconnection, a fundamental astrophysical process taking place in the highly conductive plasma of a star — its superheated matter. Magnetic reconnection is when magnetic field lines abruptly break, rearrange and reconnect. In this scenario, tangled magnetic fields would release energy, accelerating particles near the white dwarf. The dense material surrounding the white dwarf might trap gamma rays, while neutrinos escape and travel toward Earth.
The researchers also studied another recurring nova, RS Ophiuchi, which erupted in 2021. They used those observations to help predict what might happen when the Blaze Star erupts.
The researchers found that neutrinos in the magnetic reconnection model could reach Earth about 9 to 10 hours earlier than photons or gamma rays. The early neutrinos could give astronomers a head start on pointing their telescopes. It could also help them determine the mechanism of what is happening in the Blaze Star system during the eruption.
By the way, because neutrinos carry no electrical charge and almost never interact with matter, they cannot be detected directly. Instead, scientists detect them by looking for the charged particles or flashes of light produced when a neutrino occasionally collides with an atom. Look here for details on neutrino detection methods.
Seeing the Blaze Star — Northern Hemisphere
Corona Borealis is almost, but not quite, circumpolar from mid-northern latitudes. So it’s not visible all year round for most northern observers, but it is up much of the year. Northern spring is the best time to start looking for this easy-to-find constellation. In northern fall, look low in the west-northwest.
No matter where you are on the globe, the constellation looks like a letter C. You’ll find Corona Borealis approximately on a line between the bright stars Arcturus and Vega. And Corona Borealis is next to another famous star pattern for those with dark skies. It’s the squarish 4-star pattern of the Keystone in Hercules the Strongman.
Did you hear those words dark sky? You can see the bright stars Arcturus and Vega from inside cities. But you’ll need a dark sky to pick out the Keystone and Corona Borealis. Visit EarthSky’s Best Places to Stargaze.
Do you need binoculars? No. You don’t need them. But binoculars are always a good idea.
Find the bright stars Vega and Arcturus. The famous squarish pattern of the Keystone in the constellation Hercules is between them. And so is an easy-to-see semicircle of stars, the constellation Corona Borealis. The Blaze Star will erupt within Corona Borealis. It’ll be about as bright as Corona Borealis’ brightest star, Alphecca. Image via NASA.
We all live under the same sky. But Earth’s Northern and Southern Hemispheres see the sky from different perspectives.
And remember how we said that Corona Borealis was almost — but not quite — circumpolar for the Northern Hemisphere? That means it’s far to the north on the sky’s dome. From deep in the Southern Hemisphere — for example, the latitude of New Zealand and southern Australia — Corona Borealis rises to only around 20 to 25 degrees above the northern horizon at its highest. So, in addition to a dark sky, you’ll also want a clear view to the north.
Look north to northeast for a delicate semicircle or backward C shape of stars between the bright orange star Arcturus and the bright blue-white star Vega. The famous Keystone pattern in Hercules is also between these two, right next to Corona Borealis.
T Coronae Borealis — called “T Cor Bor” by many — is located about 3,000 light-years from Earth. It’s a double star system, consisting of a large cool star and a smaller hot star, which orbit each other every 228 days.
This system is what’s called a recurring nova. It’s not a supernova or star that blows itself to bits. Novas operate differently from supernovas. They survive to brighten again. T Cor Bor has outbursts about every 80 years.
Its last outburst was in 1946. That’s why astronomers believe another outburst will occur soon.
What makes the nova erupt? The cool star in the T Corona Borealis system is a swollen red giant. It continually transfers material to its companion in the system, the hot star. The hot star is a white dwarf, surrounded by an accretion disk made of material transferred over from the other star.
All of this is hidden inside a dense cloud of material from the red giant. When the system is quiescent, the red giant dominates the visible light output of the entire system. So the system appears as an M3 giant.
But during outbursts, the transfer of material from the red giant to the hot white dwarf increases greatly. The hot star then expands. And the luminosity of the system increases. Voila. We have a nova.
View larger. Here’s the location of T Corona Borealis, on a more detailed chart used by variable star observers. Image via the American Association of Variable Star Observers (AAVSO).
Why hasn’t the Blaze Star blazed?
Astronomers have been waiting several years for the Blaze Star to erupt. One recent prediction came from Jean Schneider of the Paris Observatory, publishing in the Research Notes of the American Astronomical Society in October 2024.
He pinpointed possible dates of March 27, 2025, and November 10, 2025. Those dates have come and gone with no big kablooey.
Schneider came to his possible dates using a combination of the previous eruption dates and the orbital data of the binary system. But Schneider admits in his paper that no one can exactly predict the eruption.
And, clearly, predicting eruptions of stars isn’t an exact science. The Blaze Star underwent two known eruptions recorded by astronomers. Those events were on May 12, 1866, and on February 9, 1946. Those eruptions were 80 years apart. So scientists thought that, in another 80 years, the star would erupt again. Eighty years from 1946 would be 2026.
And still we wait …
Artist’s concept of a red giant star and white dwarf star. A stream of material flows from the red giant to the white dwarf, eventually causing a runaway thermonuclear reaction on the white dwarf that will appear as a new star, or nova, in earthly skies. The constellation Corona Borealis the Northern Crown should have a nova appear from the Blaze Star approximately every 80 years. Image via NASA/ Goddard Space Flight Center.
How bright will the Blaze Star be?
How bright will it get in our sky? Astronomers expect it to reach an apparent magnitude of 2. That’s a respectable brightness for a star. It’s conveniently comparable to the brightest star in the Northern Crown, the Jewel of the Crown, Alphecca. So, for a few days, the Northern Crown will have two jewels!
T Corona Borealis — the Blaze Star — is also one of the most distant stars you’ll ever see. Alphecca is around 75 light-years away, while the Blaze Star is 3,000 light-years away.
So that gives you some perspective on the absolute magnitude (brightness) of this enormous blast. The actual explosion of the Blaze Star nova will likely dwarf any explosion you’ll ever see. But the star is far away. This explosion has traveled 3,000 years to get here. So, in relative terms, the nova will have happened during the Bronze Age.
Remember when viewing Alphecca and T Corona Borealis side-by-side with approximately the same brightness, the nova is 40 times farther away than Alphecca. Also, we are not seeing the two stars at the same moment in time. One we see as it was 75 years ago. And the other we see as it was 3,000 years ago. It can be hard to get your head around that!
The nova will brighten the star by thousands of times, typically over just a few hours, and then take some days to fade away again. When it’s done, it will go back to its normal appearance … which means we won’t be able to see it anymore, with the eye alone.
So erupt already!
View at EarthSky Community Photos. | Paul Henkiel of Flagstaff, Arizona, captured this image on April 30, 2024. It’s the easy-to-spot C-shaped constellation Corona Borealis the Northern Crown. The brightest star here is Alphecca, aka Gemma, sometimes called the Jewel of the Crown. When the Blaze Star erupts, it’ll be approximately as bright as Alphecca. The Northern Crown will have 2 jewels! Thank you, Paul!
Bottom line: Astronomers are still waiting for the Blaze Star, T Coronae Borealis, to erupt. New research suggests neutrinos could provide an early warning of its next outburst. Here’s how to find it in the sky.
DarkSky.org is holding its annual dark sky conference on November 6-7, 2026. The event is called Under One Sky. Image via DarkSky.org.
Dark sky conference: Under One Sky, November 6-7
DarkSky International is a worldwide group aimed at combating light pollution. In 2026, its annual conference, titled Under One Sky, will be held virtually on November 6-7. The 24-hour event brings together a growing global community committed to reducing light pollution and protecting the night through advocacy and conservation.
DarkSky International describes what you can expect from the conference:
Under One Sky unites leading experts, inspiring storytellers, and dedicated advocates to share solutions and tools for preserving the night. From astronomers exploring distant galaxies to entomologists studying nocturnal insects, the conference covers topics as diverse as the night itself.
Experience transformative talks, insightful panels, and interactive workshops designed to empower you to make a difference in your community. Whether you’re improving urban lighting, protecting rural skies or promoting responsible astrotourism, there’s a session for you.
More about light pollution
The loss of the dark night sky has been happening for decades. Astronomers have even coined the word noctalgia (sky grief) for their sadness at the loss of dark skies. Approximately 99% of people in the U.S. and Europe live under light-polluted skies. And some 80% of people in North America can’t see the Milky Way from where they live.
But there is some good news. This year NASA shared a map of where the lights at night are getting dimmer. Read more about that here.
How are the skies where you live? This light pollution map can help you find the darkest skies close to home. Or visit EarthSky’s Best Places to Stargaze page to get recommendations from our community on where to enjoy dark skies.
Artist’s concept showing dark skies versus more light-polluted skies. Sometimes astronomers talk about the Bortle scale. This is a rating given to an area’s night sky based on how many stars you can see due to light pollution. A higher number is a more light-polluted sky. A lower number is a more pristine sky. Image via Stellarium Labs.
Bottom line: On November 6-7, 2026, DarkSky International will hold a virtual dark sky conference called Under One Sky. Learn more about it here.
DarkSky.org is holding its annual dark sky conference on November 6-7, 2026. The event is called Under One Sky. Image via DarkSky.org.
Dark sky conference: Under One Sky, November 6-7
DarkSky International is a worldwide group aimed at combating light pollution. In 2026, its annual conference, titled Under One Sky, will be held virtually on November 6-7. The 24-hour event brings together a growing global community committed to reducing light pollution and protecting the night through advocacy and conservation.
DarkSky International describes what you can expect from the conference:
Under One Sky unites leading experts, inspiring storytellers, and dedicated advocates to share solutions and tools for preserving the night. From astronomers exploring distant galaxies to entomologists studying nocturnal insects, the conference covers topics as diverse as the night itself.
Experience transformative talks, insightful panels, and interactive workshops designed to empower you to make a difference in your community. Whether you’re improving urban lighting, protecting rural skies or promoting responsible astrotourism, there’s a session for you.
More about light pollution
The loss of the dark night sky has been happening for decades. Astronomers have even coined the word noctalgia (sky grief) for their sadness at the loss of dark skies. Approximately 99% of people in the U.S. and Europe live under light-polluted skies. And some 80% of people in North America can’t see the Milky Way from where they live.
But there is some good news. This year NASA shared a map of where the lights at night are getting dimmer. Read more about that here.
How are the skies where you live? This light pollution map can help you find the darkest skies close to home. Or visit EarthSky’s Best Places to Stargaze page to get recommendations from our community on where to enjoy dark skies.
Artist’s concept showing dark skies versus more light-polluted skies. Sometimes astronomers talk about the Bortle scale. This is a rating given to an area’s night sky based on how many stars you can see due to light pollution. A higher number is a more light-polluted sky. A lower number is a more pristine sky. Image via Stellarium Labs.
Bottom line: On November 6-7, 2026, DarkSky International will hold a virtual dark sky conference called Under One Sky. Learn more about it here.
EarthSky’s Kelly Kizer Whitt explains how to see Earth’s shadow and the Belt of Venus, in this video.
Earth’s shadow is easy to see
You can see the shadow of Earth cast onto Earth’s atmosphere twice a day as a bluish band adjacent to the horizon. Just look east after sunset or west before sunrise. Like all worlds orbiting a sun, Earth casts a shadow. It extends some 870,000 miles (1.4 million km) into space. And like all shadows, the shadow of Earth is always opposite the sun.
Plus, the pretty band of pink that lies on top of Earth’s bluish shadow is called the Belt of Venus. More on that below!
You’ll see Earth’s shadow as deep blue-gray. It’s darker than the blue of the twilight sky.
Earth’s shadow is big. It helps to be on a hill or somewhere you have a long view of the horizon. You might have to turn your head this way and that — along the arc of the horizon opposite the sun — to see the whole thing. And, just so you’ll recognize it more easily, remember that the shadow is curved, in exactly the same way that the whole Earth is curved.
Once you spot it, don’t go back inside just yet. Wait a while, and watch Earth’s shadow ascending or descending at exactly the same rate that the sun is rising or setting on the opposite horizon.
And here’s a fun thought … night itself is a shadow. When night falls, you’re standing within the shadow of Earth.
View at EarthSky Community Photos. | Jelieta Walinski captured this image on November 5, 2025, from Arizona and wrote: “As twilight embraced Montezuma Pass, I turned my lens toward the quiet horizon with Mexico resting beneath the breath of dusk. There it was, the Belt of Venus, a delicate blush of rose-pink caressing the edge of the world, wrapped above the deepening Earth’s shadow, a quiet blue veil cast by our own planet upon its sky. This ethereal belt forms when sunlight scatters through Earth’s atmosphere, reflecting from the opposite horizon just as the sun dips below it. The pink hue arises from backscattered reddened sunlight, while the darker band beneath is the Earth’s umbra, slowly rising as night claims the day. Between these two – light and shadow – the heavens whisper of cycles eternal: dusk to dawn, day to night, and the tender reminder that even Earth casts beauty in its own shadow.” Thank you, Jelieta!
What exactly is the Belt of Venus?
The Belt of Venus, that pink band of sky above Earth’s shadow, also has the name of the anti-twilight arch. So, for example, during sunset, the colors of twilight will be happening in the west, and when you turn to the opposite horizon, you’ll see the anti-twilight arch. You’ve probably noticed that sometimes the whole sky seems colorful at sunset. There’s a good chance that what you’re seeing opposite the sunset is Earth’s shadow and the Belt of Venus.
When the sun is below the horizon, some of the sun’s rays of light still reach our atmosphere. The light passes through our atmosphere and — at the antisolar point — it backscatters. That light then reaches back to us in shades of pink.
You might think that the Belt of Venus got its name from the planet Venus. Venus, orbiting inside Earth’s orbit, never strays far from the sun in our sky. So we often see it around sunrise and sunset. But, of course, the sun is on the opposite side of the sky from the Belt of Venus. So if Venus is visible in the sky, it’s near the sun, not on the opposite horizon.
Instead, like many other objects we know in the sky, it gets its name from ancient myth. The Belt of Venus is named for the goddess of love’s pink girdle.
View at EarthSky Community Photos. | Cecille Kennedy captured this image on October 7, 2025, from Oregon and wrote: “Harvest Super Moon setting at Pirate Cove with the Belt of Venus colors.” Thank you, Cecille!
Our shadow is why we see lunar eclipses
Earth’s shadow extends so far into space that it can touch the moon. A lunar eclipse is when the moon passes through Earth’s shadow.
When the sun, Earth and moon align in space (nearly or perfectly), with Earth between the sun and moon, Earth’s shadow falls on the moon’s face. That’s when people on Earth see the shadow gradually turn a bright full moon into a dark lunar eclipse.
As seen from Earth’s surface, there are typically two or more lunar eclipses every year. Some are total, some are partial, and others are a subtle kind of eclipse known as penumbral.
During a lunar eclipse, a very small amount of light from the sun filters through Earth’s atmosphere onto Earth’s shadow on the moon. That’s why — during the middle of a total lunar eclipse — the shadow on the moon looks reddish.
A lunar eclipse takes place when the sun, Earth and full moon line up in space. The full moon passes through Earth’s shadow. Image via Wikimedia Commons.
The view from space
Another way to appreciate Earth’s shadow is simply to see it from space.
The image below provides a beautiful view of Earth at night. It’s a composite image, assembled from data acquired by the Suomi National Polar-orbiting Partnership (Suomi NPP) satellite over nine days in April 2012 and 13 days in October 2012.
EarthSky’s global community shares amazing photos with us every day. Here are some of their images of Earth’s shadow. Do you have a great photo to share? Submit it here!
View at EarthSky Community Photos. | Teresa Molinaro captured this image on November 5, 2025, from Italy and wrote: “The November full moon rises above the sea, bathed in the twilight colors of the Earth’s shadow on the atmosphere and the rosy Belt of Venus.” Thank you, Teresa!View larger. | Jan Curtis captured this view of the full moon rising in Earth’s shadow with the pink Belt of Venus above on November 30, 2020, from Wyoming. In this image, you can see the curve of the blue shadow that mimics the curve of Earth. Image via Jan Curtis. Used with permission.EarthSky’s Marcy Curran captured this image from Wyoming of the full Super Beaver Moon on November 15, 2024, lying in the Belt of Venus and above Earth’s shadow.View at EarthSky Community Photos. | EarthSky’s own Kelly Kizer Whitt captured this image of Earth’s shadow and the Belt of Venus on November 13, 2023.
More EarthSky Community Photos
View at EarthSky Community Photos. | Jelieta Walinski captured this image on March 3, 2026, from Arizona. Jelieta wrote: “After witnessing the crimson drama of a lunar eclipse, we packed our telescopes and prepared to leave Montezuma Pass. But through the windshield, the sky whispered one more lesson. Stretching above the mountains was the delicate pink arc known as the Belt of Venus. Beneath it, a deep bluish band — Earth’s shadow itself — rising opposite the sun. This is the same shadow that had painted the moon red hours before. Now, at dawn, we see it from the outside: our planet casting its vast silhouette into its own atmosphere.” Thank you, Jelieta!
View at EarthSky Community Photos. | Stephanie Longo captured this image of Earth’s shadow (on the right side) and the pink Belt of Venus before sunrise on February 2, 2020. Thank you, Stephanie!
View at EarthSky Community Photos. | Cissy Beasley captured the moon on September 30, 2020, from Rockport, Texas. She wrote: “As a professional nature photographer, I eagerly embrace opportunities to capture scenes of sunrises and sunsets, and the moon. Last night, I found a nice spot for documenting the rising moon amid the Belt of Venus. Here is what I saw!” Gorgeous, Cissy. Thank you!
Bottom line: You can see Earth’s shadow in both the evening and morning sky. It appears as a bluish band opposite the sun. Above that you may see a pink band, which carries the pretty name of the Belt of Venus.
EarthSky’s Kelly Kizer Whitt explains how to see Earth’s shadow and the Belt of Venus, in this video.
Earth’s shadow is easy to see
You can see the shadow of Earth cast onto Earth’s atmosphere twice a day as a bluish band adjacent to the horizon. Just look east after sunset or west before sunrise. Like all worlds orbiting a sun, Earth casts a shadow. It extends some 870,000 miles (1.4 million km) into space. And like all shadows, the shadow of Earth is always opposite the sun.
Plus, the pretty band of pink that lies on top of Earth’s bluish shadow is called the Belt of Venus. More on that below!
You’ll see Earth’s shadow as deep blue-gray. It’s darker than the blue of the twilight sky.
Earth’s shadow is big. It helps to be on a hill or somewhere you have a long view of the horizon. You might have to turn your head this way and that — along the arc of the horizon opposite the sun — to see the whole thing. And, just so you’ll recognize it more easily, remember that the shadow is curved, in exactly the same way that the whole Earth is curved.
Once you spot it, don’t go back inside just yet. Wait a while, and watch Earth’s shadow ascending or descending at exactly the same rate that the sun is rising or setting on the opposite horizon.
And here’s a fun thought … night itself is a shadow. When night falls, you’re standing within the shadow of Earth.
View at EarthSky Community Photos. | Jelieta Walinski captured this image on November 5, 2025, from Arizona and wrote: “As twilight embraced Montezuma Pass, I turned my lens toward the quiet horizon with Mexico resting beneath the breath of dusk. There it was, the Belt of Venus, a delicate blush of rose-pink caressing the edge of the world, wrapped above the deepening Earth’s shadow, a quiet blue veil cast by our own planet upon its sky. This ethereal belt forms when sunlight scatters through Earth’s atmosphere, reflecting from the opposite horizon just as the sun dips below it. The pink hue arises from backscattered reddened sunlight, while the darker band beneath is the Earth’s umbra, slowly rising as night claims the day. Between these two – light and shadow – the heavens whisper of cycles eternal: dusk to dawn, day to night, and the tender reminder that even Earth casts beauty in its own shadow.” Thank you, Jelieta!
What exactly is the Belt of Venus?
The Belt of Venus, that pink band of sky above Earth’s shadow, also has the name of the anti-twilight arch. So, for example, during sunset, the colors of twilight will be happening in the west, and when you turn to the opposite horizon, you’ll see the anti-twilight arch. You’ve probably noticed that sometimes the whole sky seems colorful at sunset. There’s a good chance that what you’re seeing opposite the sunset is Earth’s shadow and the Belt of Venus.
When the sun is below the horizon, some of the sun’s rays of light still reach our atmosphere. The light passes through our atmosphere and — at the antisolar point — it backscatters. That light then reaches back to us in shades of pink.
You might think that the Belt of Venus got its name from the planet Venus. Venus, orbiting inside Earth’s orbit, never strays far from the sun in our sky. So we often see it around sunrise and sunset. But, of course, the sun is on the opposite side of the sky from the Belt of Venus. So if Venus is visible in the sky, it’s near the sun, not on the opposite horizon.
Instead, like many other objects we know in the sky, it gets its name from ancient myth. The Belt of Venus is named for the goddess of love’s pink girdle.
View at EarthSky Community Photos. | Cecille Kennedy captured this image on October 7, 2025, from Oregon and wrote: “Harvest Super Moon setting at Pirate Cove with the Belt of Venus colors.” Thank you, Cecille!
Our shadow is why we see lunar eclipses
Earth’s shadow extends so far into space that it can touch the moon. A lunar eclipse is when the moon passes through Earth’s shadow.
When the sun, Earth and moon align in space (nearly or perfectly), with Earth between the sun and moon, Earth’s shadow falls on the moon’s face. That’s when people on Earth see the shadow gradually turn a bright full moon into a dark lunar eclipse.
As seen from Earth’s surface, there are typically two or more lunar eclipses every year. Some are total, some are partial, and others are a subtle kind of eclipse known as penumbral.
During a lunar eclipse, a very small amount of light from the sun filters through Earth’s atmosphere onto Earth’s shadow on the moon. That’s why — during the middle of a total lunar eclipse — the shadow on the moon looks reddish.
A lunar eclipse takes place when the sun, Earth and full moon line up in space. The full moon passes through Earth’s shadow. Image via Wikimedia Commons.
The view from space
Another way to appreciate Earth’s shadow is simply to see it from space.
The image below provides a beautiful view of Earth at night. It’s a composite image, assembled from data acquired by the Suomi National Polar-orbiting Partnership (Suomi NPP) satellite over nine days in April 2012 and 13 days in October 2012.
EarthSky’s global community shares amazing photos with us every day. Here are some of their images of Earth’s shadow. Do you have a great photo to share? Submit it here!
View at EarthSky Community Photos. | Teresa Molinaro captured this image on November 5, 2025, from Italy and wrote: “The November full moon rises above the sea, bathed in the twilight colors of the Earth’s shadow on the atmosphere and the rosy Belt of Venus.” Thank you, Teresa!View larger. | Jan Curtis captured this view of the full moon rising in Earth’s shadow with the pink Belt of Venus above on November 30, 2020, from Wyoming. In this image, you can see the curve of the blue shadow that mimics the curve of Earth. Image via Jan Curtis. Used with permission.EarthSky’s Marcy Curran captured this image from Wyoming of the full Super Beaver Moon on November 15, 2024, lying in the Belt of Venus and above Earth’s shadow.View at EarthSky Community Photos. | EarthSky’s own Kelly Kizer Whitt captured this image of Earth’s shadow and the Belt of Venus on November 13, 2023.
More EarthSky Community Photos
View at EarthSky Community Photos. | Jelieta Walinski captured this image on March 3, 2026, from Arizona. Jelieta wrote: “After witnessing the crimson drama of a lunar eclipse, we packed our telescopes and prepared to leave Montezuma Pass. But through the windshield, the sky whispered one more lesson. Stretching above the mountains was the delicate pink arc known as the Belt of Venus. Beneath it, a deep bluish band — Earth’s shadow itself — rising opposite the sun. This is the same shadow that had painted the moon red hours before. Now, at dawn, we see it from the outside: our planet casting its vast silhouette into its own atmosphere.” Thank you, Jelieta!
View at EarthSky Community Photos. | Stephanie Longo captured this image of Earth’s shadow (on the right side) and the pink Belt of Venus before sunrise on February 2, 2020. Thank you, Stephanie!
View at EarthSky Community Photos. | Cissy Beasley captured the moon on September 30, 2020, from Rockport, Texas. She wrote: “As a professional nature photographer, I eagerly embrace opportunities to capture scenes of sunrises and sunsets, and the moon. Last night, I found a nice spot for documenting the rising moon amid the Belt of Venus. Here is what I saw!” Gorgeous, Cissy. Thank you!
Bottom line: You can see Earth’s shadow in both the evening and morning sky. It appears as a bluish band opposite the sun. Above that you may see a pink band, which carries the pretty name of the Belt of Venus.
Update: NASA tried to rescue the falling Swift spacecraft by boosting it back into a higher orbit, but that mission failed in August. And now the spacecraft will likely reenter Earth’s atmosphere around Wednesday. The latest estimate of reentry has been moved up a bit because of recent active solar weather, which degrades a spacecraft’s orbit.
Currently, the estimate for the Swift spacecraft reentry is November 4, 2026, at 05:31 UTC ± 12 hours. If you want to see if the fiery reentry might be visible from your location, you can visit the Swift Last Light website.
In the Americas, the current timing would put it in the afternoon/evening of Tuesday, November 3, or overnight on Wednesday, November 4.
Watch more about Swift
Watch EarthSky’s Dave Adalian talk with Brad Cenko, principal investigator of the Neil Gehrels Swift Observatory.
Due to an ongoing commercial spacecraft attitude control issue, NASA and Katalyst Space announced Wednesday the LINK spacecraft will not capture or boost an agency satellite to a higher altitude to extend its science mission as planned.
Katalyst Space had launched LINK, a spacecraft meant to capture the failing Swift satellite and boost it into a higher orbit. Swift is a space telescope that watches for events such as gamma-ray bursts. But after more than 20 years, the spacecraft’s orbit has been quickly decaying. It needed a boost back in space or it would crash back to Earth. Unfortunately, the rescue mission will not be able to provide that boost after all. So Swift will fall back to Earth sometime in 2026. Experts expect it will burn up entirely when it hits the atmosphere, so it should not be a danger to anyone on the ground.
Why can’t Swift be saved?
Katalyst’s LINK spacecraft has recently experienced attitude control issues. So it will not be able to capture Swift and boost it higher above Earth. Still, while the main purpose of the mission has failed, NASA and Katalyst will continue to conduct rendezvous and proximity operations with Swift to gather information for the future. NASA Administrator Jared Isaacman said:
This is not the outcome we were working toward, but it does not change why this mission was worth attempting. The team moved with extraordinary speed to give Swift a chance to carry out more science while advancing capabilities America will need for satellite servicing in the future. We are going to learn everything we can from LINK’s rendezvous attempt and put those lessons to work on the missions that follow.
Stay tuned as we learn later this year just when and where Swift will reenter Earth’s atmosphere, likely in October.
LINK as the would-be rescuer
The Neil Gehrels Swift Observatory, better known as Swift, has been orbiting Earth since 2004. It has been studying the most powerful explosions in the universe: gamma-ray bursts. Now, Swift’s orbit is rapidly decaying. That means Swift is slowly falling back to Earth.
And now it looks like nothing will stop it. It’s now destined to put on a spectacular, fiery show.
NASA tried to stop Swift’s fall with a 2nd spacecraft. The would-be rescuer was a commercial robotic repair vehicle called LINK, by Katalyst Space. It launched on July 3, 2026.
So LINK was supposed to chase down Swift, grab it, and raise its orbit. But about three weeks into the mission, two of LINK’s three reaction wheels failed, sending LINK into an uncontrolled spin and causing communication to be intermittent.
A view of the rescue attempt
Amateur astronomers in Puerto Rico – with the Sociedad de Astronomía del Caribe – captured video of both LINK and Swift in the same (or a similar) orbit around Earth. The video comes from Añasco, Puerto Rico, at about 8:02–8:03 p.m. AST on August 10, 2026. Watch the video at the top of this post. And keep reading to learn more.
Meet the space-based Swift Observatory. Its orbit is decaying; it is falling back to Earth. NASA planned to save it and boost it to a higher orbit, with a rescue mission called LINK. The intervention failed and Swift will plunge back to Earth by the fall of 2026. Image via NASA.
Seeing Swift and LINK in orbit
Amateur astronomers frequently try to spy faint spacecraft in orbit around Earth, and LINK and Swift are no exceptions. The website Heavens-Above.com is designed specifically to enable observers to become aware of satellite passes from their location.
The Sociedad de Astronomia del Caribe in Añasco, Puerto Rico, caught both Swift and LINK on video on August 2, 2026. That earlier video showed that Link was about 8 minutes behind the Swift spacecraft.
But, between August 9 and 10, the club’s cameras showed LINK as slightly ahead of Swift in orbit. That’s what you’ll see if you watch the video above.
In the Sociedad de Astronomia del Caribe video at the top of this post, the Link rescue spacecraft passes very close to a bright star. The star is Antares, brightest light in the constellation Scorpius the Scorpion. A minute later, the Swift Observatory is seen also passing by this bright star.
The video capture was possible by analyzing the trajectory of both spacecraft using various sources including Heavens-Above.com.
Observers can try to glimpse the decaying Swift Observatory with the eye. It sometimes reaches a visual magnitude around +2.0 to +1.5, making it as bright as a moderately bright star.
It would be especially easy to spot if you were observing far from city lights, once you know where to look.
The Link rescue spacecraft is fainter and more difficult to see. But some experienced observers have reported seeing it with the unaided eye.
How to spot Swift or LINK
To spot the Swift Observatory or the LINK rescue vehicle in orbit using the website Heavens-Above.com, you need custom visibility predictions for your exact location.
Here’s how to set your observing location:
Navigate to the Heavens-Above main site or open the Heavens-Above mobile app.
Click on Configuration (or the location selector in the upper-right corner).
Input your specific city or exact GPS coordinates so that pass times and trajectory angles calculate accurately for your horizon.
Here’s how to find the 2 spacecraft:
Return to the main database menu and locate the Satellites section.
Select Search database for satellite (or use the Satellite database / Search link).
Query for Swift (the Neil Gehrels Swift Observatory, NORAD ID 28485) or LINK (or Katalyst Space / Pegasus XL payload related to the mission).
Here’s how to generate the pass predictions:
Open the satellite’s details page and click 10-day predictions for visible passes (or change filters to show “All passes” if you want daytime/radio passes).
Review the pass table for key metrics. These are: start/ highest/ end times; altitude aka elevation (look for passes exceeding 30 to 40 degrees elevation for clear viewing above trees or buildings); and brightness aka magnitude (lower or negative numbers indicate brighter objects, and Swift typically reaches a visual magnitude of around +1.5 to +2.0, making it visible to the unaided eye under dark sky conditions.)
Here’s how to use the interactive sky charts
Click on any specific date/pass row to generate a star chart.
The chart overlays the satellite’s precise trajectory against recognizable constellations and stars (such as Scorpius or Antares), showing you exactly where to aim your eyes, binoculars, or camera equipment.
Engineers from Katalyst Space test the LINK spacecraft before it was launched in an attempt to save Swift. Image via Scott Wiessinger/ NASA.
More about the Swift spacecraft
The Swift spacecraft has three telescopes that watch the night sky. They are the Burst Alert Telescope, X-Ray Telescope and Ultraviolet/Optical Telescope.
The Burst Alert Telescope (BAT) is Swift’s wide-field gamma-ray detector. This telescope continuously monitors a large portion of the sky, watching for sudden flashes of high-energy gamma rays from gamma-ray bursts. When it detects a burst, it quickly calculates the object’s position and sends the coordinates to astronomers worldwide. It also directs the Swift spacecraft to rapidly turn toward the event for closer study.
X-Ray Telescope and Ultraviolet/Optical Telescope
Once Swift has slewed toward a newly detected gamma-ray burst, the X-Ray Telescope (XRT) takes over. It observes the burst’s fading X-ray afterglow. And it measures how its brightness changes over time and analyzes the energies of the emitted X-rays. Also, the XRT can pinpoint a burst’s location better than BAT and can continue tracking the event for days or even weeks. So the XRT helps scientists understand the physics of these powerful explosions and their environments.
Finally, the Ultraviolet/Optical Telescope studies gamma-ray bursts and other cosmic objects in ultraviolet and visible light. It provides Swift’s most precise positions for newly discovered bursts. It also captures details about their brightness, color and evolution. Overall, these observations help astronomers determine distances, identify host galaxies and better understand the nature of the explosions and other transient events Swift observes across the universe.
Bottom line: The Swift spacecraft is falling back to Earth. It will likely burn up in our atmosphere on November 3 or 4. Will you see it?
Update: NASA tried to rescue the falling Swift spacecraft by boosting it back into a higher orbit, but that mission failed in August. And now the spacecraft will likely reenter Earth’s atmosphere around Wednesday. The latest estimate of reentry has been moved up a bit because of recent active solar weather, which degrades a spacecraft’s orbit.
Currently, the estimate for the Swift spacecraft reentry is November 4, 2026, at 05:31 UTC ± 12 hours. If you want to see if the fiery reentry might be visible from your location, you can visit the Swift Last Light website.
In the Americas, the current timing would put it in the afternoon/evening of Tuesday, November 3, or overnight on Wednesday, November 4.
Watch more about Swift
Watch EarthSky’s Dave Adalian talk with Brad Cenko, principal investigator of the Neil Gehrels Swift Observatory.
Due to an ongoing commercial spacecraft attitude control issue, NASA and Katalyst Space announced Wednesday the LINK spacecraft will not capture or boost an agency satellite to a higher altitude to extend its science mission as planned.
Katalyst Space had launched LINK, a spacecraft meant to capture the failing Swift satellite and boost it into a higher orbit. Swift is a space telescope that watches for events such as gamma-ray bursts. But after more than 20 years, the spacecraft’s orbit has been quickly decaying. It needed a boost back in space or it would crash back to Earth. Unfortunately, the rescue mission will not be able to provide that boost after all. So Swift will fall back to Earth sometime in 2026. Experts expect it will burn up entirely when it hits the atmosphere, so it should not be a danger to anyone on the ground.
Why can’t Swift be saved?
Katalyst’s LINK spacecraft has recently experienced attitude control issues. So it will not be able to capture Swift and boost it higher above Earth. Still, while the main purpose of the mission has failed, NASA and Katalyst will continue to conduct rendezvous and proximity operations with Swift to gather information for the future. NASA Administrator Jared Isaacman said:
This is not the outcome we were working toward, but it does not change why this mission was worth attempting. The team moved with extraordinary speed to give Swift a chance to carry out more science while advancing capabilities America will need for satellite servicing in the future. We are going to learn everything we can from LINK’s rendezvous attempt and put those lessons to work on the missions that follow.
Stay tuned as we learn later this year just when and where Swift will reenter Earth’s atmosphere, likely in October.
LINK as the would-be rescuer
The Neil Gehrels Swift Observatory, better known as Swift, has been orbiting Earth since 2004. It has been studying the most powerful explosions in the universe: gamma-ray bursts. Now, Swift’s orbit is rapidly decaying. That means Swift is slowly falling back to Earth.
And now it looks like nothing will stop it. It’s now destined to put on a spectacular, fiery show.
NASA tried to stop Swift’s fall with a 2nd spacecraft. The would-be rescuer was a commercial robotic repair vehicle called LINK, by Katalyst Space. It launched on July 3, 2026.
So LINK was supposed to chase down Swift, grab it, and raise its orbit. But about three weeks into the mission, two of LINK’s three reaction wheels failed, sending LINK into an uncontrolled spin and causing communication to be intermittent.
A view of the rescue attempt
Amateur astronomers in Puerto Rico – with the Sociedad de Astronomía del Caribe – captured video of both LINK and Swift in the same (or a similar) orbit around Earth. The video comes from Añasco, Puerto Rico, at about 8:02–8:03 p.m. AST on August 10, 2026. Watch the video at the top of this post. And keep reading to learn more.
Meet the space-based Swift Observatory. Its orbit is decaying; it is falling back to Earth. NASA planned to save it and boost it to a higher orbit, with a rescue mission called LINK. The intervention failed and Swift will plunge back to Earth by the fall of 2026. Image via NASA.
Seeing Swift and LINK in orbit
Amateur astronomers frequently try to spy faint spacecraft in orbit around Earth, and LINK and Swift are no exceptions. The website Heavens-Above.com is designed specifically to enable observers to become aware of satellite passes from their location.
The Sociedad de Astronomia del Caribe in Añasco, Puerto Rico, caught both Swift and LINK on video on August 2, 2026. That earlier video showed that Link was about 8 minutes behind the Swift spacecraft.
But, between August 9 and 10, the club’s cameras showed LINK as slightly ahead of Swift in orbit. That’s what you’ll see if you watch the video above.
In the Sociedad de Astronomia del Caribe video at the top of this post, the Link rescue spacecraft passes very close to a bright star. The star is Antares, brightest light in the constellation Scorpius the Scorpion. A minute later, the Swift Observatory is seen also passing by this bright star.
The video capture was possible by analyzing the trajectory of both spacecraft using various sources including Heavens-Above.com.
Observers can try to glimpse the decaying Swift Observatory with the eye. It sometimes reaches a visual magnitude around +2.0 to +1.5, making it as bright as a moderately bright star.
It would be especially easy to spot if you were observing far from city lights, once you know where to look.
The Link rescue spacecraft is fainter and more difficult to see. But some experienced observers have reported seeing it with the unaided eye.
How to spot Swift or LINK
To spot the Swift Observatory or the LINK rescue vehicle in orbit using the website Heavens-Above.com, you need custom visibility predictions for your exact location.
Here’s how to set your observing location:
Navigate to the Heavens-Above main site or open the Heavens-Above mobile app.
Click on Configuration (or the location selector in the upper-right corner).
Input your specific city or exact GPS coordinates so that pass times and trajectory angles calculate accurately for your horizon.
Here’s how to find the 2 spacecraft:
Return to the main database menu and locate the Satellites section.
Select Search database for satellite (or use the Satellite database / Search link).
Query for Swift (the Neil Gehrels Swift Observatory, NORAD ID 28485) or LINK (or Katalyst Space / Pegasus XL payload related to the mission).
Here’s how to generate the pass predictions:
Open the satellite’s details page and click 10-day predictions for visible passes (or change filters to show “All passes” if you want daytime/radio passes).
Review the pass table for key metrics. These are: start/ highest/ end times; altitude aka elevation (look for passes exceeding 30 to 40 degrees elevation for clear viewing above trees or buildings); and brightness aka magnitude (lower or negative numbers indicate brighter objects, and Swift typically reaches a visual magnitude of around +1.5 to +2.0, making it visible to the unaided eye under dark sky conditions.)
Here’s how to use the interactive sky charts
Click on any specific date/pass row to generate a star chart.
The chart overlays the satellite’s precise trajectory against recognizable constellations and stars (such as Scorpius or Antares), showing you exactly where to aim your eyes, binoculars, or camera equipment.
Engineers from Katalyst Space test the LINK spacecraft before it was launched in an attempt to save Swift. Image via Scott Wiessinger/ NASA.
More about the Swift spacecraft
The Swift spacecraft has three telescopes that watch the night sky. They are the Burst Alert Telescope, X-Ray Telescope and Ultraviolet/Optical Telescope.
The Burst Alert Telescope (BAT) is Swift’s wide-field gamma-ray detector. This telescope continuously monitors a large portion of the sky, watching for sudden flashes of high-energy gamma rays from gamma-ray bursts. When it detects a burst, it quickly calculates the object’s position and sends the coordinates to astronomers worldwide. It also directs the Swift spacecraft to rapidly turn toward the event for closer study.
X-Ray Telescope and Ultraviolet/Optical Telescope
Once Swift has slewed toward a newly detected gamma-ray burst, the X-Ray Telescope (XRT) takes over. It observes the burst’s fading X-ray afterglow. And it measures how its brightness changes over time and analyzes the energies of the emitted X-rays. Also, the XRT can pinpoint a burst’s location better than BAT and can continue tracking the event for days or even weeks. So the XRT helps scientists understand the physics of these powerful explosions and their environments.
Finally, the Ultraviolet/Optical Telescope studies gamma-ray bursts and other cosmic objects in ultraviolet and visible light. It provides Swift’s most precise positions for newly discovered bursts. It also captures details about their brightness, color and evolution. Overall, these observations help astronomers determine distances, identify host galaxies and better understand the nature of the explosions and other transient events Swift observes across the universe.
Bottom line: The Swift spacecraft is falling back to Earth. It will likely burn up in our atmosphere on November 3 or 4. Will you see it?
