Event Horizon Telescope probes source of 3,000-light-year-long black hole jet

The smooth, rounded glow is an elliptical galaxy made of roughly a trillion stars: the giant galaxy M87. The blue stream is its black hole jet — a relativistic outflow of particles launched from near the galaxy’s central supermassive black hole and extending about 3,000 light-years into space. The Event Horizon Telescope has now probed the jet’s source. Image via A Hubble Space Telescope/ NASA/ ESA/ STScI/ Alec Lessing (Stanford University)/ Michael Shara (AMNH).

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

• New Event Horizon Telescope (EHT) observations have traced the origin of the powerful jet back in the galaxy M87 to near the galaxy’s central supermassive black hole.
• Including more telescopes at large distances from each other – especially the ALMA telescope in Chile – provided crucial detail.
• These results bring scientists closer to understanding how black holes launch relativistic jets, powerful jets of radiation and particles thousands of light-years long and traveling close to the speed of light.

NRAO originally published this article on January 28, 2026. Edits by EarthSky.

Event Horizon Telescope probes M87 black hole jet

Astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) and other radio telescopes in the Event Horizon Telescope (EHT) network have taken a major step toward pinpointing where the powerful jet from the supermassive black hole in galaxy M87 originates. Their study connects the black hole’s famous ring of light to a compact region that marks the likely base of the jet. And this finding brings scientists closer to understanding how black holes power some of the brightest beacons in the universe.

The giant elliptical galaxy M87, is located about 55 million light-years from Earth. Additionally, it hosts a supermassive black hole with a mass roughly six billion times that of our sun. This black hole generates a bright, narrow jet of particles that blasts out of the galaxy’s core. And this jet stretches for about 3,000 light-years into space.

Event Horizon Telescope is global

To study small regions this small so far away, astronomers linked radio telescopes around the globe into a virtual Earth-sized telescope. It’s known as the Event Horizon Telescope (EHT). One of them ALMA, is a partner of the U.S. National Science Foundation National Radio Astronomy Observatory (NSF NRAO). Alma is one of the most sensitive and critical stations in this network. It enabled the EHT’s ability to detect fine details in the gas and jet close to the black hole.

By using EHT observations of M87 from 2021, the team was able to compare how bright the radio emission appears on different spatial scales. As a result, they found that the glowing ring around the black hole cannot explain all of its radio light. However, they found an additional compact source, about 0.09 light-years from the black hole. And it matches the predicted location of the jet’s base.

So by using ALMA as a baseline and connecting it with other observatories, other structures were revealed that link the black hole’s immediate surroundings to the larger-scale jet. Thus, astronomers bridged the gap between the ring and the jet and used computer models to test how jets are launched.

Future studies are needed

Naturally, future EHT observations that include ALMA and additional telescopes. For example, the Large Millimeter Telescope in Mexico, will sharpen its view even further. Researchers hope to determine the base of the jet from their studies. Plus, they aim to directly image the region where matter near the black hole is funneled into the jet. This would increase our knowledge and understanding of black hole physics.

Bottom line: New observations with the Event Horizon Telescope trace the M87 black hole jet back to its likely source, linking to the famous ring of light at the jet’s base.

Via: New Event Horizon Telescope Results Trace M87 Jet Back to Its Black Hole

Read more: M87’s jet has a double-helix structure

Read more: New image of M87’s supermassive black hole

The post Event Horizon Telescope probes source of 3,000-light-year-long black hole jet first appeared on EarthSky.

from EarthSky https://ift.tt/db7Ynas

The smooth, rounded glow is an elliptical galaxy made of roughly a trillion stars: the giant galaxy M87. The blue stream is its black hole jet — a relativistic outflow of particles launched from near the galaxy’s central supermassive black hole and extending about 3,000 light-years into space. The Event Horizon Telescope has now probed the jet’s source. Image via A Hubble Space Telescope/ NASA/ ESA/ STScI/ Alec Lessing (Stanford University)/ Michael Shara (AMNH).

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

• New Event Horizon Telescope (EHT) observations have traced the origin of the powerful jet back in the galaxy M87 to near the galaxy’s central supermassive black hole.
• Including more telescopes at large distances from each other – especially the ALMA telescope in Chile – provided crucial detail.
• These results bring scientists closer to understanding how black holes launch relativistic jets, powerful jets of radiation and particles thousands of light-years long and traveling close to the speed of light.

NRAO originally published this article on January 28, 2026. Edits by EarthSky.

Event Horizon Telescope probes M87 black hole jet

Astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) and other radio telescopes in the Event Horizon Telescope (EHT) network have taken a major step toward pinpointing where the powerful jet from the supermassive black hole in galaxy M87 originates. Their study connects the black hole’s famous ring of light to a compact region that marks the likely base of the jet. And this finding brings scientists closer to understanding how black holes power some of the brightest beacons in the universe.

The giant elliptical galaxy M87, is located about 55 million light-years from Earth. Additionally, it hosts a supermassive black hole with a mass roughly six billion times that of our sun. This black hole generates a bright, narrow jet of particles that blasts out of the galaxy’s core. And this jet stretches for about 3,000 light-years into space.

Event Horizon Telescope is global

To study small regions this small so far away, astronomers linked radio telescopes around the globe into a virtual Earth-sized telescope. It’s known as the Event Horizon Telescope (EHT). One of them ALMA, is a partner of the U.S. National Science Foundation National Radio Astronomy Observatory (NSF NRAO). Alma is one of the most sensitive and critical stations in this network. It enabled the EHT’s ability to detect fine details in the gas and jet close to the black hole.

By using EHT observations of M87 from 2021, the team was able to compare how bright the radio emission appears on different spatial scales. As a result, they found that the glowing ring around the black hole cannot explain all of its radio light. However, they found an additional compact source, about 0.09 light-years from the black hole. And it matches the predicted location of the jet’s base.

So by using ALMA as a baseline and connecting it with other observatories, other structures were revealed that link the black hole’s immediate surroundings to the larger-scale jet. Thus, astronomers bridged the gap between the ring and the jet and used computer models to test how jets are launched.

Future studies are needed

Naturally, future EHT observations that include ALMA and additional telescopes. For example, the Large Millimeter Telescope in Mexico, will sharpen its view even further. Researchers hope to determine the base of the jet from their studies. Plus, they aim to directly image the region where matter near the black hole is funneled into the jet. This would increase our knowledge and understanding of black hole physics.

Bottom line: New observations with the Event Horizon Telescope trace the M87 black hole jet back to its likely source, linking to the famous ring of light at the jet’s base.

Via: New Event Horizon Telescope Results Trace M87 Jet Back to Its Black Hole

Read more: M87’s jet has a double-helix structure

Read more: New image of M87’s supermassive black hole

The post Event Horizon Telescope probes source of 3,000-light-year-long black hole jet first appeared on EarthSky.

from EarthSky https://ift.tt/db7Ynas

Oldest known rock art in the world found in Indonesian cave

Adam Brumm of Griffith University discusses the 67,800-year-old rock art.

Scientists have discovered the world’s oldest known rock art, a 67,800-year-old hand stencil, in a cave on an island off Sulawesi, Indonesia.

The ancient print suggests modern humans were creating symbolic art in that region much earlier than previously known.

The finding supports the idea that early humans took a northward route through Sulawesi on their way to Australia.

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

A new record for reliably dated rock art

About 67,800 years ago, someone coated their hand in a pigment and pressed it against a cave wall. Amazingly, this has survived the erosive effects of time, and remains faintly visible in a cave in Muna, an island off Sulawesi, Indonesia.

On January 22, 2026, scientists announced that this remarkable hand stencil is the oldest known rock art in the world. Moreover, it provides new clues about the migration of modern humans (Homo sapiens) through southern Southeast Asia on their way to Australia.

In addition, the scientists reported that ancient humans had been repeatedly creating art on the walls of this cave until 20,000 years ago. Maxime Aubert of Griffith University is a co-author of the paper on this study. He said in a statement:

It is now evident from our new phase of research that Sulawesi was home to one of the world’s richest and most longstanding artistic cultures, one with origins in the earliest history of human occupation of the island at least 67,800 years ago.

The researchers published their findings in the peer-reviewed journal Nature on January 21, 2026.

The faint 67,800 yr old rock art – a hand stencil – is barely visible between 2 more recent, but also old, rock art figures. Image via Griffith University.

An unusual feature of the hand stencil

The research team dated the ancient hand stencil by analyzing minute calcium carbonate deposits that accumulated on top of the rock art, using a technique called uranium-series dating.

The 67,800-year-old hand stencil, labeled LMET2, is the faint orange marking between 2 more recent figures that are also ancient. There is another marking, labeled LMET1, dated to 60,900 years ago. The section labeled “b” shows a digital tracing of the rock art. Image via Oktaviana, A. A., et al./ Nature (CC BY-NC-ND 4.0)

The ancient hand stencil pigment, significantly faded by time, showed parts of the fingers and adjoining palm area. Notably, at least one finger appeared to have been deliberately narrowed by the artist. As a result, it appeared like a claw-like hand.

What was the symbolic significance of that alteration? Adam Brumm of Griffith University speculated:

This art could symbolize the idea that humans and animals were closely connected, something we already seem to see in the very early painted art of Sulawesi, with at least one instance of a scene portraying figures that we interpret as representations of part-human, part-animal beings.

What this rock art says about early human migration

Several Indonesian islands have some of the oldest rock art in the world. In fact, people have found figures and hand stencils in caves at Sulawesi and Kalimantan, ranging from 17,000 to 51,000 years old.

Now, the 67,800-year-old hand stencil sets a new record. The researchers think that this artwork in the Muna cave was created by people closely associated with the ancestors of indigenous Australians.

Archaic hominins – other types of human species – may have also been present in Sulawesi. However, the team thinks that modern humans made this oldest rock art. They wrote in their paper:

We attribute the earliest cave art of Muna to H. sapiens based on the added technical and stylistic complexity of the intentionally modified fingers on the hand stencil and the close fit with the known arrival time of our species in the region.

Adhi Agus Oktaviana, of the National Research and Innovation Agency in Indonesia, is the paper’s lead author. He commented:

It is very likely that the people who made these paintings in Sulawesi were part of the broader population that would later spread through the region and ultimately reach Australia.

Some of the scientists who discovered the oldest rock art: Maxime Aubert, Budianto Hakim, Adam Brumm and Adhi Agus Oktaviana. Image via Griffith University.

The debate over when humans arrived in Australia

The first modern humans to venture towards Australia used a combination of land migration, when sea levels were low, and sea voyages, to make their journey. During the latter part of the Pleistocene (2.6 million to 11,700 years ago), there was a landmass called Sahul that joined Australia and New Guinea. Fluctuating sea levels, during glacial cycles, submerged and exposed parts of this landmass.

However, researchers had been divided over when modern humans made their way to Sahul. Was it 50,000 years ago or 65,000 years ago?

Oktaviana said:

This discovery strongly supports the idea that the ancestors of the First Australians were in Sahul by 65,000 years ago.

Clues to how early modern humans reached Australia

Scientists think there were two possible routes that led to Sahul. In one scenario, humans took a northern path to the New Guinea section of Sahul. This involved island-hopping through Sulawesi and the Maluku islands. However, there’s also a southerly option where sea voyagers went directly to the Australian mainland through Timor and nearby islands.

This map shows the current view of southern Southeast Asia. The areas shaded in grey are exposed land when the sea level was low. The red arrows show the northern route, through Sulawesi, towards Australia. The blue arrow shows another proposed southern route. According to the scientists, the new rock art strongly suggests that early modern humans took the northern route to Australia. Image via Oktaviana, A. A., et al./ Nature (CC BY-NC-ND 4.0)

Renaud Joannes-Boyau of the Southern Cross University, and a paper co-author, says that the rock art suggests a northern route:

With the dating of this extremely ancient rock art in Sulawesi, we now have the oldest direct evidence for the presence of modern humans along this northern migration corridor into Sahul.

The researchers are continuing to search for signs of early modern human habitation in the islands along the northern route. Aubert remarked:

These discoveries underscore the archaeological importance of the many other Indonesian islands between Sulawesi and westernmost New Guinea.

Bottom line: Scientists discovered the oldest known rock art in a cave on an island off Sulawesi, Indonesia. The 67,800-year-old art provides new clues to human migration to Australia.

Source: Rock art from at least 67,800 years ago in Sulawesi

Via Griffith University

Read more: Last known appearance of Homo erectus was in Ngandong, Java

The post Oldest known rock art in the world found in Indonesian cave first appeared on EarthSky.

from EarthSky https://ift.tt/7RScjy9

Adam Brumm of Griffith University discusses the 67,800-year-old rock art.

Scientists have discovered the world’s oldest known rock art, a 67,800-year-old hand stencil, in a cave on an island off Sulawesi, Indonesia.

The ancient print suggests modern humans were creating symbolic art in that region much earlier than previously known.

The finding supports the idea that early humans took a northward route through Sulawesi on their way to Australia.

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

A new record for reliably dated rock art

About 67,800 years ago, someone coated their hand in a pigment and pressed it against a cave wall. Amazingly, this has survived the erosive effects of time, and remains faintly visible in a cave in Muna, an island off Sulawesi, Indonesia.

On January 22, 2026, scientists announced that this remarkable hand stencil is the oldest known rock art in the world. Moreover, it provides new clues about the migration of modern humans (Homo sapiens) through southern Southeast Asia on their way to Australia.

In addition, the scientists reported that ancient humans had been repeatedly creating art on the walls of this cave until 20,000 years ago. Maxime Aubert of Griffith University is a co-author of the paper on this study. He said in a statement:

It is now evident from our new phase of research that Sulawesi was home to one of the world’s richest and most longstanding artistic cultures, one with origins in the earliest history of human occupation of the island at least 67,800 years ago.

The researchers published their findings in the peer-reviewed journal Nature on January 21, 2026.

The faint 67,800 yr old rock art – a hand stencil – is barely visible between 2 more recent, but also old, rock art figures. Image via Griffith University.

An unusual feature of the hand stencil

The research team dated the ancient hand stencil by analyzing minute calcium carbonate deposits that accumulated on top of the rock art, using a technique called uranium-series dating.

The 67,800-year-old hand stencil, labeled LMET2, is the faint orange marking between 2 more recent figures that are also ancient. There is another marking, labeled LMET1, dated to 60,900 years ago. The section labeled “b” shows a digital tracing of the rock art. Image via Oktaviana, A. A., et al./ Nature (CC BY-NC-ND 4.0)

The ancient hand stencil pigment, significantly faded by time, showed parts of the fingers and adjoining palm area. Notably, at least one finger appeared to have been deliberately narrowed by the artist. As a result, it appeared like a claw-like hand.

What was the symbolic significance of that alteration? Adam Brumm of Griffith University speculated:

This art could symbolize the idea that humans and animals were closely connected, something we already seem to see in the very early painted art of Sulawesi, with at least one instance of a scene portraying figures that we interpret as representations of part-human, part-animal beings.

What this rock art says about early human migration

Several Indonesian islands have some of the oldest rock art in the world. In fact, people have found figures and hand stencils in caves at Sulawesi and Kalimantan, ranging from 17,000 to 51,000 years old.

Now, the 67,800-year-old hand stencil sets a new record. The researchers think that this artwork in the Muna cave was created by people closely associated with the ancestors of indigenous Australians.

Archaic hominins – other types of human species – may have also been present in Sulawesi. However, the team thinks that modern humans made this oldest rock art. They wrote in their paper:

We attribute the earliest cave art of Muna to H. sapiens based on the added technical and stylistic complexity of the intentionally modified fingers on the hand stencil and the close fit with the known arrival time of our species in the region.

Adhi Agus Oktaviana, of the National Research and Innovation Agency in Indonesia, is the paper’s lead author. He commented:

It is very likely that the people who made these paintings in Sulawesi were part of the broader population that would later spread through the region and ultimately reach Australia.

Some of the scientists who discovered the oldest rock art: Maxime Aubert, Budianto Hakim, Adam Brumm and Adhi Agus Oktaviana. Image via Griffith University.

The debate over when humans arrived in Australia

The first modern humans to venture towards Australia used a combination of land migration, when sea levels were low, and sea voyages, to make their journey. During the latter part of the Pleistocene (2.6 million to 11,700 years ago), there was a landmass called Sahul that joined Australia and New Guinea. Fluctuating sea levels, during glacial cycles, submerged and exposed parts of this landmass.

However, researchers had been divided over when modern humans made their way to Sahul. Was it 50,000 years ago or 65,000 years ago?

Oktaviana said:

This discovery strongly supports the idea that the ancestors of the First Australians were in Sahul by 65,000 years ago.

Clues to how early modern humans reached Australia

Scientists think there were two possible routes that led to Sahul. In one scenario, humans took a northern path to the New Guinea section of Sahul. This involved island-hopping through Sulawesi and the Maluku islands. However, there’s also a southerly option where sea voyagers went directly to the Australian mainland through Timor and nearby islands.

This map shows the current view of southern Southeast Asia. The areas shaded in grey are exposed land when the sea level was low. The red arrows show the northern route, through Sulawesi, towards Australia. The blue arrow shows another proposed southern route. According to the scientists, the new rock art strongly suggests that early modern humans took the northern route to Australia. Image via Oktaviana, A. A., et al./ Nature (CC BY-NC-ND 4.0)

Renaud Joannes-Boyau of the Southern Cross University, and a paper co-author, says that the rock art suggests a northern route:

With the dating of this extremely ancient rock art in Sulawesi, we now have the oldest direct evidence for the presence of modern humans along this northern migration corridor into Sahul.

The researchers are continuing to search for signs of early modern human habitation in the islands along the northern route. Aubert remarked:

These discoveries underscore the archaeological importance of the many other Indonesian islands between Sulawesi and westernmost New Guinea.

Bottom line: Scientists discovered the oldest known rock art in a cave on an island off Sulawesi, Indonesia. The 67,800-year-old art provides new clues to human migration to Australia.

Source: Rock art from at least 67,800 years ago in Sulawesi

Via Griffith University

Read more: Last known appearance of Homo erectus was in Ngandong, Java

The post Oldest known rock art in the world found in Indonesian cave first appeared on EarthSky.

from EarthSky https://ift.tt/7RScjy9

Messier objects are fuzzy patches in the night sky

View larger. | What are Messier objects? Here are all 110 Messier objects with their respective M numbers. Image via Wikipedia (CC BY 4.0).

The complete list of 110 Messier objects is called the Messier Catalog. And they are classified in three broad categories, as either nebulae, star clusters or galaxies.

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

What are Messier objects?

The Messier list starts with 103 deep-sky objects observed by the 18th century French astronomer Charles Messier. Seven more objects added in the 20th century bring the list up to 110 objects. Specifically, these deep-sky objects refer to astronomical bodies other than stars or planets. The Messier objects all appear as fuzzy, nebulous patches in the sky.

The names of Messier objects come from their number in the original catalog by Charles Messier. For example, the Pleiades star cluster is number 45, Messier 45 or simply M45. In addition to their numbers, many Messier objects have common names, such as the Pleiades, aka the 7 Sisters.

A small telescope can easily observe Messier objects. And a few are visible using only binoculars or even just the eye alone.

Since all the Messier objects are fairly bright, finding Messier objects is an ideal project for the beginning stargazer.

A Messier marathon: See all Messier objects

In addition, every year in March, all 110 Messier objects are visible during a single night. Stargazers around the world take advantage of this coincidence and plan a so-called Messier marathon. Basically, participants use telescopes or binoculars and attempt to see as many Messier objects as possible throughout 12 continuous hours of darkness. In order to see them all, observations must start at sunset and end at sunrise the following morning. Anyone observing 100 or more objects is happy with their results.

However, remember a few Messier objects are hard to catch because they are only visible very close to the horizon. For best results, use a Messier marathon search sequence list and hunt down the objects in order. First, right after sunset, find the galaxies M77 and M74. Last, just before dawn, catch the globular clusters M72 and M30 plus the asterism M73. The date for a Messier marathon is always on the new moon nearest the spring equinox. You can relax off and on during the night while waiting for the next batch of Messier objects to rise. Or enjoy other wonderful deep-sky objects keeping you busy all night.

A bit of history

Ironically, Charles Messier never intended to compile a list of deep-sky objects. Because Messier was a comet hunter, he began cataloging nebulous objects that are often mistaken for comets. In short, those nebulous objects also appear as visually diffuse bodies, just like a comet. Comets were important in the 18th century because astronomers were tracking their orbits. That data successfully validated Newton’s theory of universal gravitation. Messier is credited with discovering 13 comets. However, Messier is remembered more for his Messier catalog than for his comet discoveries.

Out of the 110 Messier objects, 41 are Messier’s observations. The first edition of the catalog came out in 1774, containing only 45 objects. Successive editions expanded the list, with another edition appearing in 1781 bringing the total to 103 objects. Astronomy writer Camille Flammarion – also a Frenchman – added object number 104 from Messier’s notes. Finally, some astronomers published a revised version in 1967, bringing the total up to 110 Messier objects.

Messier lived and worked in Paris, France, at a latitude of 49 degrees north. Hence, he only could observe the entire northern celestial hemisphere, and about half of the southern sky. Consequently, this explains why some notable southern objects, like the globular cluster Omega Centauri, are not on the list. Plus, the bright Eta Carinae nebula is not a Messier object. Also, the very obvious Perseus Double Cluster in the northern celestial hemisphere is not included on the list.

Messier 45, the Pleiades

View at EarthSky Community Photos. | Chicky Leclair in Helotes, Texas, completed this long exposure of the Pleiades star cluster on December 25, 2025. Chicky wrote: “This image is a mega-stack combining data capture across 11 sessions with a total of 4,623 images equating to nearly 50 hours of data. Thanks to a great community of software script developers and YouTube educators who freely share their tools and knowledge. I spent several hours learning how to use some of these new tools over the past 2 weeks and tried out my new process on this image. Definitely a keeper. Incredible results for a compact, smart telescope.” Thank you, Chicky!

Messier 31, the Andromeda galaxy

View at EarthSky Community Photos. | Ernest Jacobs captured this image of the Andromeda galaxy (M31) from New York on September 20, 2025, and wrote: “Hard to believe it has been just over 100 years since humanity established that the spiral nebulae they were observing were in fact other galaxies. Edwin Hubble provided the critical evidence observations of M31. This is a favorite target for visual observation as well as imaging.” Thank you, Ernest!

Messier 13, The great globular cluster in Hercules

View at EarthSky Community Photos. | Gwen Forrester in DeKalb County, Tennessee, captured this telescopic view of Messier 13, the Great Hercules Cluster, on May 23, 2025. Thank you, Gwen!

Messier 42, the Orion nebula

View at EarthSky Community Photos. | Shivam Sanap imaged the Orion nebula (M42) on August 2, 2025, from India, and wrote: “I captured the Orion nebula after a lot of hard work, and the results are truly amazing!”. Thank you, Shivam!

Useful references for Messier objects

A nice reference for stargazers with a telescope is a book titled Deep-Sky Companions: The Messier objects, now in its second edition. Written by the renowned amateur astronomer Stephen James O’Meara, this book includes over 100 drawings from pencil illustrating the true visual appearance of Messier objects, as viewed from Hawaii with a small refracting telescope.

NASA has a beautiful photographic gallery of some Messier objects from the Hubble Space Telescope.

Bottom line: Messier objects are a list of 110 star clusters, nebulae and galaxies, compiled by comet-hunter Charles Messier in the 1700s.

The post Messier objects are fuzzy patches in the night sky first appeared on EarthSky.

from EarthSky https://ift.tt/O4ajWsh

View larger. | What are Messier objects? Here are all 110 Messier objects with their respective M numbers. Image via Wikipedia (CC BY 4.0).

The complete list of 110 Messier objects is called the Messier Catalog. And they are classified in three broad categories, as either nebulae, star clusters or galaxies.

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

What are Messier objects?

The Messier list starts with 103 deep-sky objects observed by the 18th century French astronomer Charles Messier. Seven more objects added in the 20th century bring the list up to 110 objects. Specifically, these deep-sky objects refer to astronomical bodies other than stars or planets. The Messier objects all appear as fuzzy, nebulous patches in the sky.

The names of Messier objects come from their number in the original catalog by Charles Messier. For example, the Pleiades star cluster is number 45, Messier 45 or simply M45. In addition to their numbers, many Messier objects have common names, such as the Pleiades, aka the 7 Sisters.

A small telescope can easily observe Messier objects. And a few are visible using only binoculars or even just the eye alone.

Since all the Messier objects are fairly bright, finding Messier objects is an ideal project for the beginning stargazer.

A Messier marathon: See all Messier objects

In addition, every year in March, all 110 Messier objects are visible during a single night. Stargazers around the world take advantage of this coincidence and plan a so-called Messier marathon. Basically, participants use telescopes or binoculars and attempt to see as many Messier objects as possible throughout 12 continuous hours of darkness. In order to see them all, observations must start at sunset and end at sunrise the following morning. Anyone observing 100 or more objects is happy with their results.

However, remember a few Messier objects are hard to catch because they are only visible very close to the horizon. For best results, use a Messier marathon search sequence list and hunt down the objects in order. First, right after sunset, find the galaxies M77 and M74. Last, just before dawn, catch the globular clusters M72 and M30 plus the asterism M73. The date for a Messier marathon is always on the new moon nearest the spring equinox. You can relax off and on during the night while waiting for the next batch of Messier objects to rise. Or enjoy other wonderful deep-sky objects keeping you busy all night.

A bit of history

Ironically, Charles Messier never intended to compile a list of deep-sky objects. Because Messier was a comet hunter, he began cataloging nebulous objects that are often mistaken for comets. In short, those nebulous objects also appear as visually diffuse bodies, just like a comet. Comets were important in the 18th century because astronomers were tracking their orbits. That data successfully validated Newton’s theory of universal gravitation. Messier is credited with discovering 13 comets. However, Messier is remembered more for his Messier catalog than for his comet discoveries.

Out of the 110 Messier objects, 41 are Messier’s observations. The first edition of the catalog came out in 1774, containing only 45 objects. Successive editions expanded the list, with another edition appearing in 1781 bringing the total to 103 objects. Astronomy writer Camille Flammarion – also a Frenchman – added object number 104 from Messier’s notes. Finally, some astronomers published a revised version in 1967, bringing the total up to 110 Messier objects.

Messier lived and worked in Paris, France, at a latitude of 49 degrees north. Hence, he only could observe the entire northern celestial hemisphere, and about half of the southern sky. Consequently, this explains why some notable southern objects, like the globular cluster Omega Centauri, are not on the list. Plus, the bright Eta Carinae nebula is not a Messier object. Also, the very obvious Perseus Double Cluster in the northern celestial hemisphere is not included on the list.

Messier 45, the Pleiades

View at EarthSky Community Photos. | Chicky Leclair in Helotes, Texas, completed this long exposure of the Pleiades star cluster on December 25, 2025. Chicky wrote: “This image is a mega-stack combining data capture across 11 sessions with a total of 4,623 images equating to nearly 50 hours of data. Thanks to a great community of software script developers and YouTube educators who freely share their tools and knowledge. I spent several hours learning how to use some of these new tools over the past 2 weeks and tried out my new process on this image. Definitely a keeper. Incredible results for a compact, smart telescope.” Thank you, Chicky!

Messier 31, the Andromeda galaxy

View at EarthSky Community Photos. | Ernest Jacobs captured this image of the Andromeda galaxy (M31) from New York on September 20, 2025, and wrote: “Hard to believe it has been just over 100 years since humanity established that the spiral nebulae they were observing were in fact other galaxies. Edwin Hubble provided the critical evidence observations of M31. This is a favorite target for visual observation as well as imaging.” Thank you, Ernest!

Messier 13, The great globular cluster in Hercules

View at EarthSky Community Photos. | Gwen Forrester in DeKalb County, Tennessee, captured this telescopic view of Messier 13, the Great Hercules Cluster, on May 23, 2025. Thank you, Gwen!

Messier 42, the Orion nebula

View at EarthSky Community Photos. | Shivam Sanap imaged the Orion nebula (M42) on August 2, 2025, from India, and wrote: “I captured the Orion nebula after a lot of hard work, and the results are truly amazing!”. Thank you, Shivam!

Useful references for Messier objects

A nice reference for stargazers with a telescope is a book titled Deep-Sky Companions: The Messier objects, now in its second edition. Written by the renowned amateur astronomer Stephen James O’Meara, this book includes over 100 drawings from pencil illustrating the true visual appearance of Messier objects, as viewed from Hawaii with a small refracting telescope.

NASA has a beautiful photographic gallery of some Messier objects from the Hubble Space Telescope.

Bottom line: Messier objects are a list of 110 star clusters, nebulae and galaxies, compiled by comet-hunter Charles Messier in the 1700s.

The post Messier objects are fuzzy patches in the night sky first appeared on EarthSky.

from EarthSky https://ift.tt/O4ajWsh

Heiligenschein is the halo around your head’s shadow

Jan Curtis caught the heiligenschein above his shadow in Wyoming. Image via Jan Curtis. Used with permission.

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

What is heiligenschein?

Heiligenschein – which means holy light in German – is a phenomenon that appears when you look down at your shadow and see a glowing light surrounding your head. This can happen when the ground is wet, such as when there is dew on the grass. But it can also happen when the ground is bone dry. It can even happen on other worlds!

The phenomenon of heiligenschein also goes by many other names, including shadow hiding, opposition surge and also the Seeliger effect.

The most common form of heiligenschein occurs when you look down at your shadow on a day when the grass is wet with dew. You might see a slight brightening around your head, like a halo reflected back up at you. So what’s happening? In this case, the sun is behind you, and bright sunlight is passing through those dew droplets and reflecting back the way it came, at the observer.

In the video below, notice the shadow of the videographer’s head and camera below the golfer. There’s a brightening around their head, giving them a subtle halo. This is an example of heiligenschein.

Dry heiligenschein

So how can you see a similar effect of a halo around your head when you’re looking at your shadow on dry ground? A more precise term for this is dry heiligenschein. In the book Weather by Storm Dunlop, he describes the effect as follows:

A similar effect occurs on dry grass, trees and other rough surfaces. Looking in the same direction as a ray of sunlight, a blade of grass (for example) hides its own shadow, but looking to the side, the shadows of other blades of grass (or leaves) begin to be visible. This hot spot may often be seen from an aircraft, apparently gliding over the surface of the fields and woods below.

What this means is that when there is a source of light directly behind you, like the sun, the ground in front of you is devoid of shadows. But just a bit farther away, objects start to have shadows again. So the spot straight out from your point of view without any shadows is brighter, creating a halo-like phenomenon.

If this sounds a bit like the phenomenon of a glory, that’s because they are created similarly. Glories are not just a bright spot but a rainbow-hued ring around the antisolar point.

I’ve seen both the dry heiligenschein and glories from airplanes. The first time I saw the dry heiligenschein, I was flying over Chicago and noticed how a sparkle would reflect back at my eye from cars and buildings and other objects below. This sparkling spot traveled along with me.

More images

You can see the Heiligenschein around the basket of the hot air balloon. Image via N. Thomas / Wikimedia Commons.

The best explanation (as always) is from Les Cowley’s website Atmospheric Optics.

Halos on other worlds

But you can even see the heiligenschein phenomenon on other worlds! That’s because, of course, the physics of light works the same throughout our solar system.

Buzz Aldrin takes a photo of Neil Armstrong on the moon. In the image, we can see heiligenschein around the shadow of Buzz Aldrin’s head. Image via NASA/ Wikimedia Commons.

As seen above, astronauts on the moon took images in which the dry heiligenschein appeared. And the Japanese spacecraft Hayabusa2 captured a remarkable image of its own shadow on the asteroid Ryugu during its visit, along with heiligenschein. These are places in the solar system with no or nearly no moisture. But the source of light behind the observer and the dry, dusty soil still produces the halo effect.

The Japanese spacecraft Hayabusa2 saw its own shadow on the asteroid Ryugu during a visit on March 8, 2019. The glow around the spacecraft is thanks to the dry heiligenschein effect. Image via JAXA.

Bottom line: Have you ever looked down at your shadow and noticed it looks like you have a bright halo around your head? That’s heiligenschein.

Read more: Airplane glory: What is it and how to spot one?

Read more: Can you see a full circle rainbow? All you need to know

The post Heiligenschein is the halo around your head’s shadow first appeared on EarthSky.

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Jan Curtis caught the heiligenschein above his shadow in Wyoming. Image via Jan Curtis. Used with permission.

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

What is heiligenschein?

Heiligenschein – which means holy light in German – is a phenomenon that appears when you look down at your shadow and see a glowing light surrounding your head. This can happen when the ground is wet, such as when there is dew on the grass. But it can also happen when the ground is bone dry. It can even happen on other worlds!

The phenomenon of heiligenschein also goes by many other names, including shadow hiding, opposition surge and also the Seeliger effect.

The most common form of heiligenschein occurs when you look down at your shadow on a day when the grass is wet with dew. You might see a slight brightening around your head, like a halo reflected back up at you. So what’s happening? In this case, the sun is behind you, and bright sunlight is passing through those dew droplets and reflecting back the way it came, at the observer.

In the video below, notice the shadow of the videographer’s head and camera below the golfer. There’s a brightening around their head, giving them a subtle halo. This is an example of heiligenschein.

Dry heiligenschein

So how can you see a similar effect of a halo around your head when you’re looking at your shadow on dry ground? A more precise term for this is dry heiligenschein. In the book Weather by Storm Dunlop, he describes the effect as follows:

A similar effect occurs on dry grass, trees and other rough surfaces. Looking in the same direction as a ray of sunlight, a blade of grass (for example) hides its own shadow, but looking to the side, the shadows of other blades of grass (or leaves) begin to be visible. This hot spot may often be seen from an aircraft, apparently gliding over the surface of the fields and woods below.

What this means is that when there is a source of light directly behind you, like the sun, the ground in front of you is devoid of shadows. But just a bit farther away, objects start to have shadows again. So the spot straight out from your point of view without any shadows is brighter, creating a halo-like phenomenon.

If this sounds a bit like the phenomenon of a glory, that’s because they are created similarly. Glories are not just a bright spot but a rainbow-hued ring around the antisolar point.

I’ve seen both the dry heiligenschein and glories from airplanes. The first time I saw the dry heiligenschein, I was flying over Chicago and noticed how a sparkle would reflect back at my eye from cars and buildings and other objects below. This sparkling spot traveled along with me.

More images

You can see the Heiligenschein around the basket of the hot air balloon. Image via N. Thomas / Wikimedia Commons.

The best explanation (as always) is from Les Cowley’s website Atmospheric Optics.

Halos on other worlds

But you can even see the heiligenschein phenomenon on other worlds! That’s because, of course, the physics of light works the same throughout our solar system.

Buzz Aldrin takes a photo of Neil Armstrong on the moon. In the image, we can see heiligenschein around the shadow of Buzz Aldrin’s head. Image via NASA/ Wikimedia Commons.

As seen above, astronauts on the moon took images in which the dry heiligenschein appeared. And the Japanese spacecraft Hayabusa2 captured a remarkable image of its own shadow on the asteroid Ryugu during its visit, along with heiligenschein. These are places in the solar system with no or nearly no moisture. But the source of light behind the observer and the dry, dusty soil still produces the halo effect.

The Japanese spacecraft Hayabusa2 saw its own shadow on the asteroid Ryugu during a visit on March 8, 2019. The glow around the spacecraft is thanks to the dry heiligenschein effect. Image via JAXA.

Bottom line: Have you ever looked down at your shadow and noticed it looks like you have a bright halo around your head? That’s heiligenschein.

Read more: Airplane glory: What is it and how to spot one?

Read more: Can you see a full circle rainbow? All you need to know

The post Heiligenschein is the halo around your head’s shadow first appeared on EarthSky.

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Elnath is a bright star close to the galactic anticenter

The galactic anticenter lies about 3 degrees to the east of the star Elnath, or Beta Tauri. Elnath is the 2nd brightest star in the constellation Taurus the Bull.

On August evenings, we look toward the center of our Milky Way galaxy. And in January and February, we do the opposite. We look opposite the galaxy’s center, toward the galactic anticenter and the galaxy’s nearest outer edge. The star Elnath (aka Beta Tauri, and sometimes called Alnath) in the constellation Taurus the Bull is the closest bright star on our sky’s dome to the galactic anticenter.

How to find Taurus’ 2nd brightest star

In fact, Elnath is easy to find if you learn to recognize the Face of the Bull in the constellation Taurus. The Face of the Bull in Taurus is shaped like the letter V. And the V-shape is fairly easy to pick out from the background stars. These stars are members of the Hyades Cluster. By mid-January, you can find the V-shape nearly overhead about three hours after sunset. This V-shape includes the brightest star in Taurus, red Aldebaran.

If you extend the right side of the letter V (the side that’s opposite Aldebaran), you come to the star Elnath. Elnath represents the Northern Horn of Taurus the Bull. It’s the 2nd-brightest star in Taurus after Aldebaran, which represents the Bull’s bloodshot eye.

So, Elnath isn’t quite as bright as Aldebaran. But it’s also part of a noticeable pattern, and it’s blue-white in color.

Use Orion to find Taurus and Elnath

What if you can’t find the Face of the Bull? Try finding Orion the Hunter first, an extremely prominent constellation. You can recognize Orion for its Belt, a short, straight row of three medium-bright stars.

Next, draw a line upward through Orion’s Belt to find Aldebaran and the V-shape group of stars outlining the Bull’s Face. Then extend the lines off the top of the V to locate the two stars marking the tips of the Bull’s horns. And the northern and brighter horn star is Elnath.

View at EarthSky Community Photos. | Miguel Ventura in Fafe, Portugal, captured this image on August 28, 2022. Thank you, Miguel! You can see Orion near the horizon. Above it is the V-shape of the Hyades and its bright star Aldebaran in Taurus. The bright bluish star far to the left is Elnath, with the galactic anticenter nearby. Above the Hyades, Miguel captured bright, orangish Mars as it visited Taurus. And near the top we see the Pleiades star cluster.

When and where to look for Elnath

In the Northern Hemisphere, we see Taurus and its stars on winter evenings. Elnath stands opposite the sun around mid-December and thus rises around sunset and sets around sunrise. In January and February, Elnath is already up in the southeast at sunset. By June, Elnath will be lost to the sun’s glare and won’t be seen at all. Excepting June, however, you can see Elnath for at least part of the night throughout the year.

Elnath stands a bit north of the ecliptic, the annual pathway of the sun in front of the background stars. Because the moon’s path is always near the ecliptic, the moon swings close to Elnath every month. Generally, the moon swings to the south of Elnath. On occasion, the moon swings far enough north that it occults – passes directly in front of – Elnath. We are currently in the midst of a series of occultations that will last until April 11, 2027.

How to locate the Milky Way’s anticenter

The galactic anticenter lies about 3 degrees to the east of the star Elnath. Three degrees is about the amount of sky that your thumb covers when held at arm’s length. The galactic anticenter isn’t a place, it’s just a direction in the sky from our perspective on Earth. Elnath is about 130 light-years away, whereas the outskirts of our galaxy’s disk are many thousands of light-years away. So Elnath is much closer and just shows the direction.

While the closest bright star to the galactic anticenter is Elnath in Taurus, the anticenter isn’t in Taurus. Instead, it lies in a neighboring constellation, Auriga the Charioteer.

This graphic shows you a top-down view, looking at the location of the sun inside the galaxy. At this season, the galactic center is behind the sun, and Earth’s nighttime side points toward the galactic anticenter. When we look opposite the center of the galaxy, we are looking toward the anticenter. Image via ESA/ Hubble/ Gaia/ DPAC.

Science of the star Elnath

Elnath sparkles white and is tinged in blue. This star’s color indicates that it has a hot surface temperature of about 13,600 Kelvin (13,300 Celsius or 24,000 Fahrenheit). Contrast this to the surface temperature of our yellow-colored sun, which is 5,800 Kelvin (5,500 C or 10,000 F).

Elnath has about 4 times the sun’s mass and shines with the firepower of 700 suns.

Elnath’s position is RA: 5h 26m 17.5s, dec: +28° 36′ 27″

Bottom line: The galactic anticenter is the position opposite the Milky Way’s center from our viewpoint on Earth. If you want to look toward the anticenter, gaze toward Elnath. This star is the 2nd-brightest star in the constellation Taurus the Bull and is just 3 degrees from the galactic anticenter, which lies nearby in the constellation Auriga.

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The galactic anticenter lies about 3 degrees to the east of the star Elnath, or Beta Tauri. Elnath is the 2nd brightest star in the constellation Taurus the Bull.

On August evenings, we look toward the center of our Milky Way galaxy. And in January and February, we do the opposite. We look opposite the galaxy’s center, toward the galactic anticenter and the galaxy’s nearest outer edge. The star Elnath (aka Beta Tauri, and sometimes called Alnath) in the constellation Taurus the Bull is the closest bright star on our sky’s dome to the galactic anticenter.

How to find Taurus’ 2nd brightest star

In fact, Elnath is easy to find if you learn to recognize the Face of the Bull in the constellation Taurus. The Face of the Bull in Taurus is shaped like the letter V. And the V-shape is fairly easy to pick out from the background stars. These stars are members of the Hyades Cluster. By mid-January, you can find the V-shape nearly overhead about three hours after sunset. This V-shape includes the brightest star in Taurus, red Aldebaran.

If you extend the right side of the letter V (the side that’s opposite Aldebaran), you come to the star Elnath. Elnath represents the Northern Horn of Taurus the Bull. It’s the 2nd-brightest star in Taurus after Aldebaran, which represents the Bull’s bloodshot eye.

So, Elnath isn’t quite as bright as Aldebaran. But it’s also part of a noticeable pattern, and it’s blue-white in color.

Use Orion to find Taurus and Elnath

What if you can’t find the Face of the Bull? Try finding Orion the Hunter first, an extremely prominent constellation. You can recognize Orion for its Belt, a short, straight row of three medium-bright stars.

Next, draw a line upward through Orion’s Belt to find Aldebaran and the V-shape group of stars outlining the Bull’s Face. Then extend the lines off the top of the V to locate the two stars marking the tips of the Bull’s horns. And the northern and brighter horn star is Elnath.

View at EarthSky Community Photos. | Miguel Ventura in Fafe, Portugal, captured this image on August 28, 2022. Thank you, Miguel! You can see Orion near the horizon. Above it is the V-shape of the Hyades and its bright star Aldebaran in Taurus. The bright bluish star far to the left is Elnath, with the galactic anticenter nearby. Above the Hyades, Miguel captured bright, orangish Mars as it visited Taurus. And near the top we see the Pleiades star cluster.

When and where to look for Elnath

In the Northern Hemisphere, we see Taurus and its stars on winter evenings. Elnath stands opposite the sun around mid-December and thus rises around sunset and sets around sunrise. In January and February, Elnath is already up in the southeast at sunset. By June, Elnath will be lost to the sun’s glare and won’t be seen at all. Excepting June, however, you can see Elnath for at least part of the night throughout the year.

Elnath stands a bit north of the ecliptic, the annual pathway of the sun in front of the background stars. Because the moon’s path is always near the ecliptic, the moon swings close to Elnath every month. Generally, the moon swings to the south of Elnath. On occasion, the moon swings far enough north that it occults – passes directly in front of – Elnath. We are currently in the midst of a series of occultations that will last until April 11, 2027.

How to locate the Milky Way’s anticenter

The galactic anticenter lies about 3 degrees to the east of the star Elnath. Three degrees is about the amount of sky that your thumb covers when held at arm’s length. The galactic anticenter isn’t a place, it’s just a direction in the sky from our perspective on Earth. Elnath is about 130 light-years away, whereas the outskirts of our galaxy’s disk are many thousands of light-years away. So Elnath is much closer and just shows the direction.

While the closest bright star to the galactic anticenter is Elnath in Taurus, the anticenter isn’t in Taurus. Instead, it lies in a neighboring constellation, Auriga the Charioteer.

This graphic shows you a top-down view, looking at the location of the sun inside the galaxy. At this season, the galactic center is behind the sun, and Earth’s nighttime side points toward the galactic anticenter. When we look opposite the center of the galaxy, we are looking toward the anticenter. Image via ESA/ Hubble/ Gaia/ DPAC.

Science of the star Elnath

Elnath sparkles white and is tinged in blue. This star’s color indicates that it has a hot surface temperature of about 13,600 Kelvin (13,300 Celsius or 24,000 Fahrenheit). Contrast this to the surface temperature of our yellow-colored sun, which is 5,800 Kelvin (5,500 C or 10,000 F).

Elnath has about 4 times the sun’s mass and shines with the firepower of 700 suns.

Elnath’s position is RA: 5h 26m 17.5s, dec: +28° 36′ 27″

Bottom line: The galactic anticenter is the position opposite the Milky Way’s center from our viewpoint on Earth. If you want to look toward the anticenter, gaze toward Elnath. This star is the 2nd-brightest star in the constellation Taurus the Bull and is just 3 degrees from the galactic anticenter, which lies nearby in the constellation Auriga.

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Challenger disaster: 40 years ago today

A photo of the Challenger crew, taken on January 9, 1986, during training at the Kennedy Space Center. From left to right: Christa McAuliffe (teacher in space) with astronauts Gregory Jarvis, Judith Resnik, Dick Scobee (mission commander), Ronald McNair, Mike Smith (pilot), and Ellison Onizuka. Image via NASA.

January 28, 1986

On this date 40 years ago, we lost the seven crew members of the Space Shuttle Challenger (mission STS-51-L) when the shuttle suffered a catastrophic structural failure just 73 seconds after launch. A failed O-ring seal in the right solid rocket booster caused the tragedy. The spacecraft disintegrated over the Atlantic Ocean, off the coast of central Florida.

The crew members

The Challenger crew were:
Gregory B. Jarvis, a payload specialist
Sharon Christa McAuliffe, teacher in space
Ronald E. McNair, mission specialist
Ellison S. Onizuka, mission specialist
Judith A. Resnik, mission specialist
Francis R. (Dick) Scobee, commander
Michael J. Smith, pilot

Cause of the Challenger disaster

Later it was learned that the O-ring failure had caused a breach in the solid rocket booster joint it was supposed to seal. The breach allowed pressurized hot gas from within the solid rocket motor to reach the outside. The hot gas impinged upon the adjacent solid rocket booster attachment hardware and external fuel tank. And this impingement, in turn, led to the separation of the right-hand solid rocket booster’s aft attachment and the structural failure of the external tank.

Aerodynamic forces then broke up the orbiter.

Space shuttle Challenger lifted off from Launch Complex 39B, Kennedy Space Center, at 11:38 EST (16:38 UTC) on January 28, 1986. Image via NASA/ Wikimedia Commons.

Bottom line: The space shuttle Challenger suffered a catastrophic structural failure just 73 seconds into its flight, after an O-ring seal in its right solid rocket booster (SRB) failed at liftoff. R.I.P Michael J. Smith, Dick Scobee, Ronald McNair, Ellison Onizuka, Christa McAuliffe, Gregory Jarvis and Judith Resnik.

The post Challenger disaster: 40 years ago today first appeared on EarthSky.

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A photo of the Challenger crew, taken on January 9, 1986, during training at the Kennedy Space Center. From left to right: Christa McAuliffe (teacher in space) with astronauts Gregory Jarvis, Judith Resnik, Dick Scobee (mission commander), Ronald McNair, Mike Smith (pilot), and Ellison Onizuka. Image via NASA.

January 28, 1986

On this date 40 years ago, we lost the seven crew members of the Space Shuttle Challenger (mission STS-51-L) when the shuttle suffered a catastrophic structural failure just 73 seconds after launch. A failed O-ring seal in the right solid rocket booster caused the tragedy. The spacecraft disintegrated over the Atlantic Ocean, off the coast of central Florida.

The crew members

The Challenger crew were:
Gregory B. Jarvis, a payload specialist
Sharon Christa McAuliffe, teacher in space
Ronald E. McNair, mission specialist
Ellison S. Onizuka, mission specialist
Judith A. Resnik, mission specialist
Francis R. (Dick) Scobee, commander
Michael J. Smith, pilot

Cause of the Challenger disaster

Later it was learned that the O-ring failure had caused a breach in the solid rocket booster joint it was supposed to seal. The breach allowed pressurized hot gas from within the solid rocket motor to reach the outside. The hot gas impinged upon the adjacent solid rocket booster attachment hardware and external fuel tank. And this impingement, in turn, led to the separation of the right-hand solid rocket booster’s aft attachment and the structural failure of the external tank.

Aerodynamic forces then broke up the orbiter.

Space shuttle Challenger lifted off from Launch Complex 39B, Kennedy Space Center, at 11:38 EST (16:38 UTC) on January 28, 1986. Image via NASA/ Wikimedia Commons.

Bottom line: The space shuttle Challenger suffered a catastrophic structural failure just 73 seconds into its flight, after an O-ring seal in its right solid rocket booster (SRB) failed at liftoff. R.I.P Michael J. Smith, Dick Scobee, Ronald McNair, Ellison Onizuka, Christa McAuliffe, Gregory Jarvis and Judith Resnik.

The post Challenger disaster: 40 years ago today first appeared on EarthSky.

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Iconic Ring nebula holds a mysterious iron bar, study finds

This is the iconic Ring nebula, as seen by combining 4 images from the WEAVE/LIFU instrument on the William Herschel Telescope in the Canary Islands, Spain. The never-before-seen “bar” across the middle is due to light emitted by ionized iron atoms. Image via Royal Astronomical Society/ University College London.

The Royal Astronomical Society originally published this story on January 16, 2026. Edits by EarthSky.

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

Iconic Ring nebula holds a mysterious iron bar, study finds

Astronomers at University College London (UCL) and Cardiff University have discovered a mysterious bar-shaped cloud of iron inside the iconic Ring nebula.

The cloud of iron atoms, described for the first time in Monthly Notices of the Royal Astronomical Society (RAS) on January 16, 2026, is in the shape of a bar or strip, and just fits inside the inner layer of the oval-shaped nebula.

The bar’s length is roughly 500 times that of Pluto’s orbit around the sun, and its mass is comparable to that of Mars.

How did it form? It’s a mystery, the astronomers say.

Discovering a hidden cloud in the Ring nebula

The French astronomer Charles Messier was the first to spot the Ring nebula in 1779. Lying in the northern constellation of Lyra the Harp, it’s a colorful shell of gas thrown off by a star as it ends the nuclear fuel-burning phase of its life. Our own sun will expel its outer layers in a similar way in a few billion years’ time.

Researchers discovered the iron cloud using the Large Integral Field Unit (LIFU) mode of a new instrument, the WHT Enhanced Area Velocity Explorer (WEAVE), installed on the Isaac Newton Group’s 4.2-meter (13.7 feet) William Herschel Telescope.

The LIFU is a bundle of hundreds of optical fibers. It has enabled the team of astronomers to obtain spectra (where light is separated into its constituent wavelengths) at every point across the entire face of the Ring nebula, and at all optical wavelengths, for the first time.

Lead author Dr Roger Wesson, based jointly at UCL and Cardiff University, said:

Even though the Ring nebula has been studied using many different telescopes and instruments, WEAVE has allowed us to observe it in a new way, providing so much more detail than before.

By obtaining a spectrum continuously across the whole nebula, we can create images of the nebula at any wavelength and determine its chemical composition at any position.

When we processed the data and scrolled through the images, one thing popped out as clear as anything: this previously unknown ‘bar’ of ionized iron atoms, in the middle of the familiar and iconic ring.

This Hubble telescope view of the Ring nebula is what we’re used to seeing. Image via The Hubble Heritage Team (AURA/STScI/NASA)

What created this iron bar?

How the iron bar formed is currently a mystery, the authors say. They will need further, more detailed observations to unravel what is going on. There are two potential scenarios: firstly, the iron bar may reveal something new about how the ejection of the nebula by the parent star progressed. Or, more intriguingly, the iron might be an arc of plasma resulting from the vaporization of a rocky planet caught up in the star’s earlier expansion.

Co-author Professor Janet Drew, also based at UCL, said:

We definitely need to know more – particularly whether any other chemical elements co-exist with the newly-detected iron, as this would probably tell us the right class of model to pursue. Right now, we are missing this important information.

The team is working on a follow-up study, and plans to obtain data using WEAVE’s LIFU at higher resolution to better understand how the bar might have formed.

An illustrative set of 8 individual WEAVE LIFU images of the Ring nebula, each showing emissions from a different atom. The color in each panel tracks the brightness of the emission, with brown-red being the most intense, shading through yellow and green to blue for the faintest emission. Image via RAS/ University College London.

More to learn

WEAVE is carrying out eight surveys over the next five years, targeting everything from nearby white dwarfs to very distant galaxies. The Stellar, Circumstellar and Interstellar Physics strand of the WEAVE survey is observing many more similar ionized nebulae across the northern Milky Way.

Dr Wesson explained:

It would be very surprising if the iron bar in the Ring is unique. So hopefully, as we observe and analyze more nebulae created in the same way, we will discover more examples of this phenomenon, which will help us to understand where the iron comes from.

Professor Scott Trager, WEAVE Project Scientist based at the University of Groningen, added:

The discovery of this fascinating, previously unknown structure in a night-sky jewel, beloved by sky watchers across the Northern Hemisphere, demonstrates the amazing capabilities of WEAVE.

We look forward to many more discoveries from this new instrument.

Bottom line: Scientists have discovered a mysterious bar of iron hidden within the iconic Ring nebula. It’s not yet clear what created it.

Via RAS

Source: WEAVE imaging spectroscopy of NGC 6720: an iron bar in the Ring

Read more: Messier objects are fuzzy patches in the night sky

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This is the iconic Ring nebula, as seen by combining 4 images from the WEAVE/LIFU instrument on the William Herschel Telescope in the Canary Islands, Spain. The never-before-seen “bar” across the middle is due to light emitted by ionized iron atoms. Image via Royal Astronomical Society/ University College London.

The Royal Astronomical Society originally published this story on January 16, 2026. Edits by EarthSky.

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

Iconic Ring nebula holds a mysterious iron bar, study finds

Astronomers at University College London (UCL) and Cardiff University have discovered a mysterious bar-shaped cloud of iron inside the iconic Ring nebula.

The cloud of iron atoms, described for the first time in Monthly Notices of the Royal Astronomical Society (RAS) on January 16, 2026, is in the shape of a bar or strip, and just fits inside the inner layer of the oval-shaped nebula.

The bar’s length is roughly 500 times that of Pluto’s orbit around the sun, and its mass is comparable to that of Mars.

How did it form? It’s a mystery, the astronomers say.

Discovering a hidden cloud in the Ring nebula

The French astronomer Charles Messier was the first to spot the Ring nebula in 1779. Lying in the northern constellation of Lyra the Harp, it’s a colorful shell of gas thrown off by a star as it ends the nuclear fuel-burning phase of its life. Our own sun will expel its outer layers in a similar way in a few billion years’ time.

Researchers discovered the iron cloud using the Large Integral Field Unit (LIFU) mode of a new instrument, the WHT Enhanced Area Velocity Explorer (WEAVE), installed on the Isaac Newton Group’s 4.2-meter (13.7 feet) William Herschel Telescope.

The LIFU is a bundle of hundreds of optical fibers. It has enabled the team of astronomers to obtain spectra (where light is separated into its constituent wavelengths) at every point across the entire face of the Ring nebula, and at all optical wavelengths, for the first time.

Lead author Dr Roger Wesson, based jointly at UCL and Cardiff University, said:

Even though the Ring nebula has been studied using many different telescopes and instruments, WEAVE has allowed us to observe it in a new way, providing so much more detail than before.

By obtaining a spectrum continuously across the whole nebula, we can create images of the nebula at any wavelength and determine its chemical composition at any position.

When we processed the data and scrolled through the images, one thing popped out as clear as anything: this previously unknown ‘bar’ of ionized iron atoms, in the middle of the familiar and iconic ring.

This Hubble telescope view of the Ring nebula is what we’re used to seeing. Image via The Hubble Heritage Team (AURA/STScI/NASA)

What created this iron bar?

How the iron bar formed is currently a mystery, the authors say. They will need further, more detailed observations to unravel what is going on. There are two potential scenarios: firstly, the iron bar may reveal something new about how the ejection of the nebula by the parent star progressed. Or, more intriguingly, the iron might be an arc of plasma resulting from the vaporization of a rocky planet caught up in the star’s earlier expansion.

Co-author Professor Janet Drew, also based at UCL, said:

We definitely need to know more – particularly whether any other chemical elements co-exist with the newly-detected iron, as this would probably tell us the right class of model to pursue. Right now, we are missing this important information.

The team is working on a follow-up study, and plans to obtain data using WEAVE’s LIFU at higher resolution to better understand how the bar might have formed.

An illustrative set of 8 individual WEAVE LIFU images of the Ring nebula, each showing emissions from a different atom. The color in each panel tracks the brightness of the emission, with brown-red being the most intense, shading through yellow and green to blue for the faintest emission. Image via RAS/ University College London.

More to learn

WEAVE is carrying out eight surveys over the next five years, targeting everything from nearby white dwarfs to very distant galaxies. The Stellar, Circumstellar and Interstellar Physics strand of the WEAVE survey is observing many more similar ionized nebulae across the northern Milky Way.

Dr Wesson explained:

It would be very surprising if the iron bar in the Ring is unique. So hopefully, as we observe and analyze more nebulae created in the same way, we will discover more examples of this phenomenon, which will help us to understand where the iron comes from.

Professor Scott Trager, WEAVE Project Scientist based at the University of Groningen, added:

The discovery of this fascinating, previously unknown structure in a night-sky jewel, beloved by sky watchers across the Northern Hemisphere, demonstrates the amazing capabilities of WEAVE.

We look forward to many more discoveries from this new instrument.

Bottom line: Scientists have discovered a mysterious bar of iron hidden within the iconic Ring nebula. It’s not yet clear what created it.

Via RAS

Source: WEAVE imaging spectroscopy of NGC 6720: an iron bar in the Ring

Read more: Messier objects are fuzzy patches in the night sky

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