Archaeologists used AI to create this image of a man fleeing in ancient Pompeii, which was destroyed during the eruption of Mount Vesuvius in 79 CE. So the image is fake … but the man was real. His skeleton was found holding a bowl over his head as he fled. Image via Pompeii Archaeological Park/ University of Padua – Digital Cultural Heritage Laboratory/ Ministry of Culture.
Archaeologists recreate Pompeii victim using AI technology
In 79 CE, Mount Vesuvius erupted above Pompeii, Italy, filling the air with flying rocks. A man ran through the streets of the Porta Stabia neighborhood, holding a terracotta bowl over his head for protection from the heavy shower of volcanic ash. But it wasn’t enough. He didn’t escape the devastation.
In 2024, archaeologists unearthed the skeleton of this man just outside one of Pompeii’s busiest gates. They found him curled up with the fractured terracotta bowl near his head. He also carried a ceramic lamp in an attempt to see through the ash-darkened streets. And he wore a small iron ring on his left little finger and carried 10 bronze coins.
On April 27, 2026, the Pompeii Archaeological Park in Italy said that, for the first time, it has reconstructed the moments just before the man’s ultimate fate, using AI digital technology.
Researchers used artificial intelligence software and photo editing techniques to create the image above. They wanted to present a scientifically sound image that was still accessible to the general public.
The Pompeii Archaeological Park, in collaboration with the University of Padua – Digital Cultural Heritage Laboratory and the Ministry of Culture, created the AI reconstruction based on the skeleton and nearby materials. Minister of Culture Alessandro Giuli talked about the intersection of excavations and AI. Giuli said:
The investigations conducted with these excavations demonstrate that innovative methodologies, used rigorously, can offer us new historical perspectives.
The vastness of archaeological data at Pompeii and beyond is now such that only with the help of artificial intelligence will we be able to adequately protect and enhance it. If used well, AI can contribute to a renewal of classical studies, narrating the classical world in a more immersive way.
The project opens a broader debate on the use of AI in archaeology: a technology that can contribute to the production of interpretative models and the improvement of communication tools, but which requires controlled and methodologically sound use, always in integration with the work of specialists.
Reconstructing the last moments
Luciano Floridi is the founding director of the Digital Ethics Center at Yale. Floridi said:
The man of Pompeii fled with a mortar on his head, a lamp in his hand, and ten coins: he carried whatever he thought was useful for orienting himself in the darkness. Two thousand years later, AI is helping us reconstruct his last moments.
AI does not replace the archaeologist. Under its control, it expands and deepens his potential and makes accessible to many what was previously accessible only to a few. Without AI, much of the heritage risks remaining unexplored for those who practice archaeology, and silent for those who love it …
AI produces hypotheses, not truths. Hypotheses must be reviewed, discussed, corrected, integrated, approved. Scientific responsibility cannot be delegated. But the risk is not that AI makes mistakes: it’s that we stop thinking by using it. The humanities teach us precisely this, to distinguish reconstruction from fantasy. Pompeii, once again, is the great laboratory that teaches us.
Pliny the Younger
The story of this man who ran for his life while trying to protect his head echoes the stories told by an eyewitness. Pliny the Younger wrote two accounts of the eruption at Pompeii. In them, he described people trying to protect their heads with objects, including tying pillows to their heads.
Photos from the excavation
The skeleton of the man was near a large terracotta bowl that had a fracture. Image via Pompeii Archaeological Park/ University of Padua – Digital Cultural Heritage Laboratory/ Ministry of Culture.Archaeologists also found a ceramic lamp near the skeleton of the man who was trying to protect his head. Image via Pompeii Archaeological Park/ University of Padua – Digital Cultural Heritage Laboratory/ Ministry of Culture.There was a second victim uncovered close to the man with the bowl protecting his head. This victim was a bit younger and likely died some hours after the first man. Archaeologists think he was overcome as he tried to run from the pyroclastic flow. A pyroclastic flow is fast-moving gas and ash that sweeps down from an eruption. These flows kill via incineration and asphyxiation. Image via Pompeii Archaeological Park/ University of Padua – Digital Cultural Heritage Laboratory/ Ministry of Culture.
Bottom line: Archaeologists have used AI technology to recreate a Pompeii victim. The man fled the volcano while trying to protect his head with a terracotta bowl.
Archaeologists used AI to create this image of a man fleeing in ancient Pompeii, which was destroyed during the eruption of Mount Vesuvius in 79 CE. So the image is fake … but the man was real. His skeleton was found holding a bowl over his head as he fled. Image via Pompeii Archaeological Park/ University of Padua – Digital Cultural Heritage Laboratory/ Ministry of Culture.
Archaeologists recreate Pompeii victim using AI technology
In 79 CE, Mount Vesuvius erupted above Pompeii, Italy, filling the air with flying rocks. A man ran through the streets of the Porta Stabia neighborhood, holding a terracotta bowl over his head for protection from the heavy shower of volcanic ash. But it wasn’t enough. He didn’t escape the devastation.
In 2024, archaeologists unearthed the skeleton of this man just outside one of Pompeii’s busiest gates. They found him curled up with the fractured terracotta bowl near his head. He also carried a ceramic lamp in an attempt to see through the ash-darkened streets. And he wore a small iron ring on his left little finger and carried 10 bronze coins.
On April 27, 2026, the Pompeii Archaeological Park in Italy said that, for the first time, it has reconstructed the moments just before the man’s ultimate fate, using AI digital technology.
Researchers used artificial intelligence software and photo editing techniques to create the image above. They wanted to present a scientifically sound image that was still accessible to the general public.
The Pompeii Archaeological Park, in collaboration with the University of Padua – Digital Cultural Heritage Laboratory and the Ministry of Culture, created the AI reconstruction based on the skeleton and nearby materials. Minister of Culture Alessandro Giuli talked about the intersection of excavations and AI. Giuli said:
The investigations conducted with these excavations demonstrate that innovative methodologies, used rigorously, can offer us new historical perspectives.
The vastness of archaeological data at Pompeii and beyond is now such that only with the help of artificial intelligence will we be able to adequately protect and enhance it. If used well, AI can contribute to a renewal of classical studies, narrating the classical world in a more immersive way.
The project opens a broader debate on the use of AI in archaeology: a technology that can contribute to the production of interpretative models and the improvement of communication tools, but which requires controlled and methodologically sound use, always in integration with the work of specialists.
Reconstructing the last moments
Luciano Floridi is the founding director of the Digital Ethics Center at Yale. Floridi said:
The man of Pompeii fled with a mortar on his head, a lamp in his hand, and ten coins: he carried whatever he thought was useful for orienting himself in the darkness. Two thousand years later, AI is helping us reconstruct his last moments.
AI does not replace the archaeologist. Under its control, it expands and deepens his potential and makes accessible to many what was previously accessible only to a few. Without AI, much of the heritage risks remaining unexplored for those who practice archaeology, and silent for those who love it …
AI produces hypotheses, not truths. Hypotheses must be reviewed, discussed, corrected, integrated, approved. Scientific responsibility cannot be delegated. But the risk is not that AI makes mistakes: it’s that we stop thinking by using it. The humanities teach us precisely this, to distinguish reconstruction from fantasy. Pompeii, once again, is the great laboratory that teaches us.
Pliny the Younger
The story of this man who ran for his life while trying to protect his head echoes the stories told by an eyewitness. Pliny the Younger wrote two accounts of the eruption at Pompeii. In them, he described people trying to protect their heads with objects, including tying pillows to their heads.
Photos from the excavation
The skeleton of the man was near a large terracotta bowl that had a fracture. Image via Pompeii Archaeological Park/ University of Padua – Digital Cultural Heritage Laboratory/ Ministry of Culture.Archaeologists also found a ceramic lamp near the skeleton of the man who was trying to protect his head. Image via Pompeii Archaeological Park/ University of Padua – Digital Cultural Heritage Laboratory/ Ministry of Culture.There was a second victim uncovered close to the man with the bowl protecting his head. This victim was a bit younger and likely died some hours after the first man. Archaeologists think he was overcome as he tried to run from the pyroclastic flow. A pyroclastic flow is fast-moving gas and ash that sweeps down from an eruption. These flows kill via incineration and asphyxiation. Image via Pompeii Archaeological Park/ University of Padua – Digital Cultural Heritage Laboratory/ Ministry of Culture.
Bottom line: Archaeologists have used AI technology to recreate a Pompeii victim. The man fled the volcano while trying to protect his head with a terracotta bowl.
The bright star Arcturus is easy to identify. Just follow the arc in the handle of the Big Dipper. In other words, follow the arc to Arcturus. Image via EarthSky.
As a result, Arcturus is the 4th-brightest star in Earth’s sky. It’s the brightest star in the northern half of the sky. It’s far enough north on the sky’s dome that – for Northern Hemisphere observers – it’s visible during some part of the night throughout most of the year.
Look for Arcturus on spring evenings in the Northern Hemisphere. There’s an easy mnemonic for finding it. Just remember the phrase follow the arc to Arcturus. So you’ll follow the arc in the Big Dipper’s handle – just draw that line outward, in your mind – until you reach this bright orange star.
Arcturus is the alpha star of a cone-shaped constellation called Boötes the Herdsman. It’s tough to see a herdsman in these stars. But you might see a kite! See the chart below.
Arcturus is in the constellation Boötes the Herdsman. Boötes has the shape of a kite, and Arcturus is at the point where you’d attach a tail. You can see it on spring evenings in the Northern Hemisphere.
It’s the brightest star in the northern half of the sky
When astronomers speak of the celestial sphere, they’re talking about the imaginary sphere of stars surrounding Earth.
Imagine Earth’s equator projected onto the sky. A line drawn all the way around the sky – above Earth’s equator – is called the celestial equator. It divides the sky into northern and southern hemispheres, much as the earthly equator does for Earth.
The three brightest stars of the sky – Sirius, Canopus and Alpha Centauri – are all south of this celestial equator.
And, meanwhile, Arcturus is north of the celestial equator. That makes Arcturus the brightest star in the northern part of the sky. But it’s only marginally brighter than the north celestial sphere’s 2nd-brightest star, blue-white Vega.
By the way … did you know? Some people think Polaris, the North Star, is the brightest star. But it’s not. It’s about the 50th brightest star! It’s famous for being located near the celestial north pole. Read about Polaris here.
History and mythology of Bootes and Arcturus
Arcturus’ constellation Boötes the Herdsman is sometimes pictured as guarding the Great Bear, or Ursa Major, which contains the Big Dipper asterism. We sometimes hear Arcturus called the Bear Guard.
In China, Arcturus’ constellation is also called the Dragon.
In some classical Greek stories, Boötes was Icarus, who flew too close to the sun.
Because it passes directly over the Hawaiian islands, Arcturus – brightest light in Bootes – was a particularly important navigational star to the islands’ indigenous inhabitants and other Polynesians.
The translation may be questioned, but Arcturus is among the few stars mentioned in the Bible. (“Which maketh Arcturus, Orion and Pleiades, and the chambers of the south” – Job 9:9, KJV, and “Canst thou bring forth Mazzaroth in his season? or canst thou guide Arcturus with his sons?” – Job 38:32, KJV.)
Arcturus is so bright, it’s can be seen in daytime
In 1635, less than three decades after the invention of the telescope, Jean-Baptiste Morin of France observed Arcturus in the daytime with a telescope.
It was the first time that any star, besides the sun and a rare supernova, had been seen telescopically during daylight hours.
You can also observe Arcturus with the unaided eye during the day. There’s an explanatioin on how to do it in this reprint of a science paper from 1911.
1933 Century of Progress Exposition in Chicago
One interesting story about Arcturus relates to the 1933 Century of Progress Exposition in Chicago. Its promoters wanted a flashy way to open the show. And somebody figured out that the light from Arcturus could start it.
At 9:15 pm on May 27, 1933, four telescopes located in different observatories captured the light from the star and focused it into photoelectric cells. The photocells in turn worked as the switch that turned on the main spotlights to open the exhibition. It’s a good thing it wasn’t cloudy!
How did this idea come about? There’d also been a World’s Fair in Chicago in 1893, 40 years earlier. And, at the time, astronomers thought that Arcturus was 40 light-years away. If so, that light left Arcturus at the end of the 1893 fair and traveled for 40 years through space, like an Olympic torch bearer, to open the 1933 show.
It was a good idea. But today’s astronomers place the distance to Arcturus at just less than 37 light-years. Oh well. Progress!
The red giant Arcturus is roughly 25 times the diameter of our sun. But it’s not the largest of the red giants, as this diagram shows. Image via Wikimedia Commons.
Arcturus compared to our sun
Arcturus is a more evolved star than our sun. Billions of years from now, our sun will be a red giant star, much as Arcturus is now.
Arcturus’ diameter is roughly 25 times greater than our sun. Because of its larger size, it radiates more than 100 times the light of our sun, in visible light. If you consider infrared and other frequencies in the electromagnetic spectrum, Arcturus is about 200 times more powerful than our sun. But its mass is only slightly greater than the sun’s.
The reddish or orange color of Arcturus signifies its temperature, which is about 7,300 degrees Fahrenheit (around 4,000 degrees Celsius). That makes it several thousand degrees cooler than the surface of our sun.
Arcturus is flying southward
Generally speaking, the stars are fixed. They are all moving through space, but we don’t see them move because they’re so far away. But Arcturus has a large proper motion, or sideways motion, on the dome of Earth’s sky. Among the 1st-magnitude (or bright) stars in our stellar neighborhood, only Alpha Centauri – our sun’s nearest neighbor among the stars – has a higher proper motion.
And of course, the large proper motion of Alpha Centauri stems from the fact that it’s so close to us.
But what does the proper motion of Arcturus tell us?
It tells us that Arcturus is moving at a tremendous speed (76 miles/s or 122 km/s) relative to our solar system. Arcturus is thought to be an old star. It appears to be moving with a group of at least 52 other such stars, known as the Arcturus stream or Arcturus moving group.
Scientists think these stars weren’t part of our Milky Way galaxy, originally. Instead, they might have come from a dwarf satellite galaxy that assimilated into the Milky Way.
From the vantage point of Earth, Arcturus is rapidly moving in a southerly direction at a rate of 3.9 arcminutes per century. It’s now at about its closest point to Earth. As it moves away, it’ll someday vanish from visibility to the unaided eye.
This will happen when it reaches the border of the southern constellations Carina and Vela … in about 150,000 years.
The position of Arcturus is RA: 14h 15 m 39.7s, dec: +19° 10′ 56″
View at EarthSky Community Photos. | Cecille Kennedy captured this image on May 1, 2025, from Oregon and wrote: “The Big Dipper, Arcturus and Polaris, the North Star, shine brightly with the other stars in the still of the blue midnight. The 2 front stars of the Big Dipper are called Pointers because they point to Polaris, the North Star. Polaris, is the brightest star in the Little Dipper and the closest bright star to the north celestial pole. When you are looking at Polaris, you are facing north. Arcturus is a 1st-magnitude star and stands right behind the Big Dipper. Arcturus is the brightest star of the constellation Boötes the Herdsman.” Thank you, Cecille!
Bottom line: Arcturus is the brightest star in the northern half of the sky. It’s easy to find in spring in the Northern Hemisphere near the handle of the Big Dipper.
The bright star Arcturus is easy to identify. Just follow the arc in the handle of the Big Dipper. In other words, follow the arc to Arcturus. Image via EarthSky.
As a result, Arcturus is the 4th-brightest star in Earth’s sky. It’s the brightest star in the northern half of the sky. It’s far enough north on the sky’s dome that – for Northern Hemisphere observers – it’s visible during some part of the night throughout most of the year.
Look for Arcturus on spring evenings in the Northern Hemisphere. There’s an easy mnemonic for finding it. Just remember the phrase follow the arc to Arcturus. So you’ll follow the arc in the Big Dipper’s handle – just draw that line outward, in your mind – until you reach this bright orange star.
Arcturus is the alpha star of a cone-shaped constellation called Boötes the Herdsman. It’s tough to see a herdsman in these stars. But you might see a kite! See the chart below.
Arcturus is in the constellation Boötes the Herdsman. Boötes has the shape of a kite, and Arcturus is at the point where you’d attach a tail. You can see it on spring evenings in the Northern Hemisphere.
It’s the brightest star in the northern half of the sky
When astronomers speak of the celestial sphere, they’re talking about the imaginary sphere of stars surrounding Earth.
Imagine Earth’s equator projected onto the sky. A line drawn all the way around the sky – above Earth’s equator – is called the celestial equator. It divides the sky into northern and southern hemispheres, much as the earthly equator does for Earth.
The three brightest stars of the sky – Sirius, Canopus and Alpha Centauri – are all south of this celestial equator.
And, meanwhile, Arcturus is north of the celestial equator. That makes Arcturus the brightest star in the northern part of the sky. But it’s only marginally brighter than the north celestial sphere’s 2nd-brightest star, blue-white Vega.
By the way … did you know? Some people think Polaris, the North Star, is the brightest star. But it’s not. It’s about the 50th brightest star! It’s famous for being located near the celestial north pole. Read about Polaris here.
History and mythology of Bootes and Arcturus
Arcturus’ constellation Boötes the Herdsman is sometimes pictured as guarding the Great Bear, or Ursa Major, which contains the Big Dipper asterism. We sometimes hear Arcturus called the Bear Guard.
In China, Arcturus’ constellation is also called the Dragon.
In some classical Greek stories, Boötes was Icarus, who flew too close to the sun.
Because it passes directly over the Hawaiian islands, Arcturus – brightest light in Bootes – was a particularly important navigational star to the islands’ indigenous inhabitants and other Polynesians.
The translation may be questioned, but Arcturus is among the few stars mentioned in the Bible. (“Which maketh Arcturus, Orion and Pleiades, and the chambers of the south” – Job 9:9, KJV, and “Canst thou bring forth Mazzaroth in his season? or canst thou guide Arcturus with his sons?” – Job 38:32, KJV.)
Arcturus is so bright, it’s can be seen in daytime
In 1635, less than three decades after the invention of the telescope, Jean-Baptiste Morin of France observed Arcturus in the daytime with a telescope.
It was the first time that any star, besides the sun and a rare supernova, had been seen telescopically during daylight hours.
You can also observe Arcturus with the unaided eye during the day. There’s an explanatioin on how to do it in this reprint of a science paper from 1911.
1933 Century of Progress Exposition in Chicago
One interesting story about Arcturus relates to the 1933 Century of Progress Exposition in Chicago. Its promoters wanted a flashy way to open the show. And somebody figured out that the light from Arcturus could start it.
At 9:15 pm on May 27, 1933, four telescopes located in different observatories captured the light from the star and focused it into photoelectric cells. The photocells in turn worked as the switch that turned on the main spotlights to open the exhibition. It’s a good thing it wasn’t cloudy!
How did this idea come about? There’d also been a World’s Fair in Chicago in 1893, 40 years earlier. And, at the time, astronomers thought that Arcturus was 40 light-years away. If so, that light left Arcturus at the end of the 1893 fair and traveled for 40 years through space, like an Olympic torch bearer, to open the 1933 show.
It was a good idea. But today’s astronomers place the distance to Arcturus at just less than 37 light-years. Oh well. Progress!
The red giant Arcturus is roughly 25 times the diameter of our sun. But it’s not the largest of the red giants, as this diagram shows. Image via Wikimedia Commons.
Arcturus compared to our sun
Arcturus is a more evolved star than our sun. Billions of years from now, our sun will be a red giant star, much as Arcturus is now.
Arcturus’ diameter is roughly 25 times greater than our sun. Because of its larger size, it radiates more than 100 times the light of our sun, in visible light. If you consider infrared and other frequencies in the electromagnetic spectrum, Arcturus is about 200 times more powerful than our sun. But its mass is only slightly greater than the sun’s.
The reddish or orange color of Arcturus signifies its temperature, which is about 7,300 degrees Fahrenheit (around 4,000 degrees Celsius). That makes it several thousand degrees cooler than the surface of our sun.
Arcturus is flying southward
Generally speaking, the stars are fixed. They are all moving through space, but we don’t see them move because they’re so far away. But Arcturus has a large proper motion, or sideways motion, on the dome of Earth’s sky. Among the 1st-magnitude (or bright) stars in our stellar neighborhood, only Alpha Centauri – our sun’s nearest neighbor among the stars – has a higher proper motion.
And of course, the large proper motion of Alpha Centauri stems from the fact that it’s so close to us.
But what does the proper motion of Arcturus tell us?
It tells us that Arcturus is moving at a tremendous speed (76 miles/s or 122 km/s) relative to our solar system. Arcturus is thought to be an old star. It appears to be moving with a group of at least 52 other such stars, known as the Arcturus stream or Arcturus moving group.
Scientists think these stars weren’t part of our Milky Way galaxy, originally. Instead, they might have come from a dwarf satellite galaxy that assimilated into the Milky Way.
From the vantage point of Earth, Arcturus is rapidly moving in a southerly direction at a rate of 3.9 arcminutes per century. It’s now at about its closest point to Earth. As it moves away, it’ll someday vanish from visibility to the unaided eye.
This will happen when it reaches the border of the southern constellations Carina and Vela … in about 150,000 years.
The position of Arcturus is RA: 14h 15 m 39.7s, dec: +19° 10′ 56″
View at EarthSky Community Photos. | Cecille Kennedy captured this image on May 1, 2025, from Oregon and wrote: “The Big Dipper, Arcturus and Polaris, the North Star, shine brightly with the other stars in the still of the blue midnight. The 2 front stars of the Big Dipper are called Pointers because they point to Polaris, the North Star. Polaris, is the brightest star in the Little Dipper and the closest bright star to the north celestial pole. When you are looking at Polaris, you are facing north. Arcturus is a 1st-magnitude star and stands right behind the Big Dipper. Arcturus is the brightest star of the constellation Boötes the Herdsman.” Thank you, Cecille!
Bottom line: Arcturus is the brightest star in the northern half of the sky. It’s easy to find in spring in the Northern Hemisphere near the handle of the Big Dipper.
This isn’t an ordinary cloud. It’s a fire-generated thunderstorm, as seen from an airplane in 2019. Weather-watchers call this a pyrocumulonimbus cloud. Lightning strikes, strong winds, and even fire tornadoes spawned by pyrocumulonimbus clouds can, in turn, make wildfires worse. Image via NOAA.
What are pyrocumulonimbus clouds?
Most people have heard of cumulonimbus clouds, those towering thunderheads that bring storms with lightning, thunder, heavy rain, hail and sometimes tornadoes. Pyro is a prefix meaning fire. And pyrocumulonimbus clouds are thunderheads that form due to fires.
So when wildfires grow large and intense, they can create their own weather. The heat and smoke from fires can rise into the atmosphere like the updraft in a thunderstorm. As the hot air ascends, it carries smoke, ash and water vapor high into the atmosphere.
If conditions are right – especially if the atmosphere is unstable – the rising plume can grow into a towering thunderstorm cloud. These clouds look quite similar to cumulonimbus clouds that produce lightning and heavy rain, except for brownish colors at their base. But pyrocumulonimbus clouds are fueled by fire rather than typical atmospheric processes.
Some pyrocumulonimbus clouds can reach heights of 30,000 to 50,000 feet (9 to 15 km)! That’s far above the height most airplanes fly. They can punch through the troposphere (the layer of air closest to Earth where we live) to the stratosphere. They can also spread out into anvil-shaped tops.
And the higher these clouds reach, the more these fires can spread smoke. It’s partly thanks to pyrocumulonimbus clouds that the smoke from wildfires can travel thousands of miles away.
Before there are pyrocumulonimbus clouds, they might be ordinary pyrocumulus clouds. This smaller version of a fire-generated cloud will have a darker, brown-tinged base. Sometimes you can see the fire beneath it, but sometimes the fire is hidden by haze or the terrain.
But as the fire grows, so can the cloud. Eventually the rising air and heat causes moisture to condense on particles, in this case, usually smoke particles. The formation of a pyrocumulonimbus cloud can bring rain. But, unfortunately, by that time the cloud has often drifted downwind. So the rain typically falls outside the fire.
And here’s an especially pernicious aspect of pyrocumulonimbus clouds. They can create lightning and thus spark new areas of fire nearby. Plus, the storms can generate strong winds that make the fire situation worse.
In fact, if the conditions are right, the storms that occur with pyrocumulonimbus clouds can even generate a fire tornado. Also known as a fire whirl, fire swirl, fire devil, firenado or fire twister, a fire tornado is a whirlwind induced by a fire and often (at least partially) composed of flame or ash.
In 2018, a firefighter was tragically killed in California when the Carr fire spawned a fire tornado. Read about it here. Or watch incredible video in the news report below.
Smoke in the upper atmosphere can last for months
In 2023, scientists with the National Oceanic and Atmospheric Administration (NOAA) released a study of pyrocumumlonimbus clouds’ effect on Earth’s atmosphere. The study showed that that smoke injected into the upper atmosphere via these clouds can stick around for months. A fire in 2017 in the Pacific Northwest put so much smoke into the atmosphere that remote sensing instruments around the globe monitored it for more than eight months.
Fires that year forced also black carbon and organic carbon into the lower stratosphere. This carbon affected our climate and temporarily cooled the planet.
These fire clouds are growing larger and more frequent.
Lead author Joe Katich, who now works for BAE Systems, said that same year:
Pyrocumulonimbus clouds contribute more to the stratospheric makeup than we thought. They act in different ways than we thought and stick around longer than we thought. This finding is important on its own. But it will also help us understand the long-term implications of solar geoengineering with aerosols. [Editor’s note: Geoengineering refers to a range of different activities that humans might undertake with the goal of cooling the Earth or removing certain gases from the atmosphere.]
Bottom line: Pyrocumulonimbus clouds are fire-driven thunderstorms. The storms can produce lightning and strong winds that make the fire situation worse.
This isn’t an ordinary cloud. It’s a fire-generated thunderstorm, as seen from an airplane in 2019. Weather-watchers call this a pyrocumulonimbus cloud. Lightning strikes, strong winds, and even fire tornadoes spawned by pyrocumulonimbus clouds can, in turn, make wildfires worse. Image via NOAA.
What are pyrocumulonimbus clouds?
Most people have heard of cumulonimbus clouds, those towering thunderheads that bring storms with lightning, thunder, heavy rain, hail and sometimes tornadoes. Pyro is a prefix meaning fire. And pyrocumulonimbus clouds are thunderheads that form due to fires.
So when wildfires grow large and intense, they can create their own weather. The heat and smoke from fires can rise into the atmosphere like the updraft in a thunderstorm. As the hot air ascends, it carries smoke, ash and water vapor high into the atmosphere.
If conditions are right – especially if the atmosphere is unstable – the rising plume can grow into a towering thunderstorm cloud. These clouds look quite similar to cumulonimbus clouds that produce lightning and heavy rain, except for brownish colors at their base. But pyrocumulonimbus clouds are fueled by fire rather than typical atmospheric processes.
Some pyrocumulonimbus clouds can reach heights of 30,000 to 50,000 feet (9 to 15 km)! That’s far above the height most airplanes fly. They can punch through the troposphere (the layer of air closest to Earth where we live) to the stratosphere. They can also spread out into anvil-shaped tops.
And the higher these clouds reach, the more these fires can spread smoke. It’s partly thanks to pyrocumulonimbus clouds that the smoke from wildfires can travel thousands of miles away.
Before there are pyrocumulonimbus clouds, they might be ordinary pyrocumulus clouds. This smaller version of a fire-generated cloud will have a darker, brown-tinged base. Sometimes you can see the fire beneath it, but sometimes the fire is hidden by haze or the terrain.
But as the fire grows, so can the cloud. Eventually the rising air and heat causes moisture to condense on particles, in this case, usually smoke particles. The formation of a pyrocumulonimbus cloud can bring rain. But, unfortunately, by that time the cloud has often drifted downwind. So the rain typically falls outside the fire.
And here’s an especially pernicious aspect of pyrocumulonimbus clouds. They can create lightning and thus spark new areas of fire nearby. Plus, the storms can generate strong winds that make the fire situation worse.
In fact, if the conditions are right, the storms that occur with pyrocumulonimbus clouds can even generate a fire tornado. Also known as a fire whirl, fire swirl, fire devil, firenado or fire twister, a fire tornado is a whirlwind induced by a fire and often (at least partially) composed of flame or ash.
In 2018, a firefighter was tragically killed in California when the Carr fire spawned a fire tornado. Read about it here. Or watch incredible video in the news report below.
Smoke in the upper atmosphere can last for months
In 2023, scientists with the National Oceanic and Atmospheric Administration (NOAA) released a study of pyrocumumlonimbus clouds’ effect on Earth’s atmosphere. The study showed that that smoke injected into the upper atmosphere via these clouds can stick around for months. A fire in 2017 in the Pacific Northwest put so much smoke into the atmosphere that remote sensing instruments around the globe monitored it for more than eight months.
Fires that year forced also black carbon and organic carbon into the lower stratosphere. This carbon affected our climate and temporarily cooled the planet.
These fire clouds are growing larger and more frequent.
Lead author Joe Katich, who now works for BAE Systems, said that same year:
Pyrocumulonimbus clouds contribute more to the stratospheric makeup than we thought. They act in different ways than we thought and stick around longer than we thought. This finding is important on its own. But it will also help us understand the long-term implications of solar geoengineering with aerosols. [Editor’s note: Geoengineering refers to a range of different activities that humans might undertake with the goal of cooling the Earth or removing certain gases from the atmosphere.]
Bottom line: Pyrocumulonimbus clouds are fire-driven thunderstorms. The storms can produce lightning and strong winds that make the fire situation worse.
The emerald belongs to the beryl family of minerals. This family also includes aquamarine (one of March’s birthstones). And it includes heliodor, aka golden or yellow beryl. It also includes morganite, which has an orange-pink color.
Beryl is a six-sided symmetrical crystal. Chemically, it contains beryllium, aluminum, silicon, and oxygen.
Emeralds vary in color from light to deep green. And it’s commonly thought that an emerald’s color derives from the presence of chromium and/or vanadium replacing some of the aluminum in the mineral’s structure.
Emeralds are known to lose their color when heated strongly.
They’re most frequently found inside a form of shale, a fine-grained sedimentary rock. Emerald-bearing shale has undergone recrystallization pressure and/or temperature changes.
Knowledge of emeralds date back to antiquity. The name emerald derives from the Greek word smaragdos, a term applied to several kinds of green stones.
Royalty wore them in ancient Babylon and Egypt. For example, Queen Cleopatra is known to have worn emeralds, during her reign in Egypt from 51–30 BCE. It’s said her emeralds probably originated from mines in southern Egypt, near the Red Sea.
And the emerald mines of ancient Egypt had tools dating back much farther, to the reign of Ramesses II. He ruled for 66 years, between 1279 and 1213 BCE. (one of the longest reigns in ancient history).
Emeralds in South America
Emeralds weren’t just a part of the “old world.” When the conquistadors first arrived in South America from Spain in the late 1400s, they saw indigenous rulers wearing emeralds.
And today, among the famous historical artifacts containing emeralds is the Crown of the Andes, made from emeralds worn by Atahualpa, the last Inca (king) of Peru. The crown is set with about 450 emeralds, collectively weighing 10 ounces (1523 carats).
The Spanish conquerors later stole large quantities of emeralds from the Peruvians. But it took them decades to discover the source of the emeralds.
It wasn’t until 1537 that the Spaniards found Chivor in Colombia, now the location of an important emerald mine. They also took over the Muzo mine in Colombia, following the defeat of the Muzo Indians. Mining operations at Muzo have continued almost uninterrupted since the Spanish invasion. It’s perhaps the most famous emerald mine in Colombia and is said to produce the world’s best emeralds.
Emeralds in Russia and elsewhere
In 1830, a Russian peasant charcoal-burner named Maxim Kozhevnikov found several green crystals in the exposed roots of a fallen tree along the banks of the Tokovaya River in the Ural Mountains of Russia. He brought the stones to the Royal Lapidary Factory in Yekaterinburg, where the director, Yakov Kokovin, identified them as high-quality emeralds. This find sparked an immediate gem rush and the establishment of official state-run mining operations in early 1831.
Today, North Carolina – in the United States – is a source for emeralds.
Around the world, they also occur in Zambia, Brazil, Pakistan, Norway, Austria, India, Madagascar, and Australia.
German chemists began making synthetic emeralds shortly before World War II. Then, growing synthetic stones of fine quality began in the United States in 1946. Also, there are excellent imitation emeralds on the market made of colored cut glass.
Bottom line: Happy birthday, May babies! The May birthstone is the emerald, a stone once worn by royalty in ancient Babylon and Egypt. Perfect emeralds are among the rarest of all gemstones.
The emerald belongs to the beryl family of minerals. This family also includes aquamarine (one of March’s birthstones). And it includes heliodor, aka golden or yellow beryl. It also includes morganite, which has an orange-pink color.
Beryl is a six-sided symmetrical crystal. Chemically, it contains beryllium, aluminum, silicon, and oxygen.
Emeralds vary in color from light to deep green. And it’s commonly thought that an emerald’s color derives from the presence of chromium and/or vanadium replacing some of the aluminum in the mineral’s structure.
Emeralds are known to lose their color when heated strongly.
They’re most frequently found inside a form of shale, a fine-grained sedimentary rock. Emerald-bearing shale has undergone recrystallization pressure and/or temperature changes.
Knowledge of emeralds date back to antiquity. The name emerald derives from the Greek word smaragdos, a term applied to several kinds of green stones.
Royalty wore them in ancient Babylon and Egypt. For example, Queen Cleopatra is known to have worn emeralds, during her reign in Egypt from 51–30 BCE. It’s said her emeralds probably originated from mines in southern Egypt, near the Red Sea.
And the emerald mines of ancient Egypt had tools dating back much farther, to the reign of Ramesses II. He ruled for 66 years, between 1279 and 1213 BCE. (one of the longest reigns in ancient history).
Emeralds in South America
Emeralds weren’t just a part of the “old world.” When the conquistadors first arrived in South America from Spain in the late 1400s, they saw indigenous rulers wearing emeralds.
And today, among the famous historical artifacts containing emeralds is the Crown of the Andes, made from emeralds worn by Atahualpa, the last Inca (king) of Peru. The crown is set with about 450 emeralds, collectively weighing 10 ounces (1523 carats).
The Spanish conquerors later stole large quantities of emeralds from the Peruvians. But it took them decades to discover the source of the emeralds.
It wasn’t until 1537 that the Spaniards found Chivor in Colombia, now the location of an important emerald mine. They also took over the Muzo mine in Colombia, following the defeat of the Muzo Indians. Mining operations at Muzo have continued almost uninterrupted since the Spanish invasion. It’s perhaps the most famous emerald mine in Colombia and is said to produce the world’s best emeralds.
Emeralds in Russia and elsewhere
In 1830, a Russian peasant charcoal-burner named Maxim Kozhevnikov found several green crystals in the exposed roots of a fallen tree along the banks of the Tokovaya River in the Ural Mountains of Russia. He brought the stones to the Royal Lapidary Factory in Yekaterinburg, where the director, Yakov Kokovin, identified them as high-quality emeralds. This find sparked an immediate gem rush and the establishment of official state-run mining operations in early 1831.
Today, North Carolina – in the United States – is a source for emeralds.
Around the world, they also occur in Zambia, Brazil, Pakistan, Norway, Austria, India, Madagascar, and Australia.
German chemists began making synthetic emeralds shortly before World War II. Then, growing synthetic stones of fine quality began in the United States in 1946. Also, there are excellent imitation emeralds on the market made of colored cut glass.
Bottom line: Happy birthday, May babies! The May birthstone is the emerald, a stone once worn by royalty in ancient Babylon and Egypt. Perfect emeralds are among the rarest of all gemstones.
The radiant point of the Eta Aquariid meteor shower is near the star Eta Aquarii in the constellation Aquarius the Water Bearer. The radiant rises in the wee hours after midnight and is still climbing toward its highest point at dawn. That highest point is in the south as viewed from the Northern Hemisphere, closer to overhead for the Southern Hemisphere. That’s why the Southern Hemisphere sees more meteors (the radiant is higher up), and it’s why – for all of us around the globe – the hours before dawn are best for this shower.
May 2026 meteors … the Eta Aquariids
When to watch: The best morning to watch is May 5, 2026, in the hours before dawn. The American Meteor Society is listing 3:51 UTC on May 5 as the shower’s predicted** peak time. The fact is that the peak of this shower stretches out over several days. So you can expect elevated numbers of meteors a few days before and after the peak time. The mornings of both May 4 and May 6 are also good times to watch! Nearest moon phase: The last quarter moon will fall at 21:10 UTC on May 9. So, there will be a waning gibbous moon in the post-midnight sky, that sets after sunrise. So the sky before dawn on the mornings around the predicted peak for the 2025 Eta Aquariids will compete with a bright gibbous moon. Find a way to block out the moon for a better view of the sky. The radiant: will rise in the wee hours, climbing toward its highest point at dawn. That’s why the hours before dawn will be the best time to watch this shower. Duration of shower: April 15 to May 27. This time period is when we’re passing through the Eta Aquariid meteor stream in space! Expected meteors at peak, under ideal conditions: The zenithal hourly rate (ZHR) of this shower (the rate at the shower’s peak, under a dark sky, with no moon, when the radiant is high in the sky) is 60. In 2026, a waning gibbous moon will severely affect this shower, reducing hourly rates. And be aware that the shower is best for latitudes like those in the southern half of the U.S. or even farther south, in the Southern Hemisphere. These are swift meteors that produce a high percentage of persistent trains. Note: The Eta Aquariids’ radiant will be on the ecliptic, which will ride low in the sky on spring mornings as seen from far northerly latitudes. This shower favors more southerly latitudes (like those in the southern U.S. or the Southern Hemisphere), where the radiant appears higher in the morning sky. It’s often the Southern Hemisphere’s best meteor shower of the year.
If you trace the paths of the Eta Aquariid meteors backward, they all seem to radiate from a point in the constellation Aquarius the Water Bearer. This point on the sky’s dome is called the radiant of the meteor shower. It nearly aligns with the faint star Eta Aquarii, and the meteor shower takes its name from this star.
Eta Aquarii is one of the four stars making up the Y-shaped Water Jarasterism in the northern part of Aquarius. If you can find the Water Jar in the constellation Aquarius, you’ve located the radiant point for the Eta Aquariid meteors. The alignment of the radiant and the star is, of course, coincidental. Eta Aquarii is some 170 light-years away – trillions upon trillions of miles away – while the Eta Aquariid meteors burn up nearby – only 60 miles (100 km) above Earth’s surface.
Meteor shower radiants are sometimes misunderstood by casual meteor-watchers. You don’t need to know where they are to watch a meteor shower. That’s because the meteors fly every way across the sky, in front of numerous constellations. However, the higher a shower’s radiant appears in your sky, the more meteors you’re likely to see. For the Eta Aquariids, the radiant soars highest in the nighttime sky just before dawn. That’s one of the reasons why you can expect to see the most meteors in the wee morning hours.
How to view a meteor shower
As with all meteors in annual showers, no special equipment is required to watch the Eta Aquariids. But a little luck always helps.
Find a dark, open sky away from artificial lights, and sprawl out on a reclining lawn chair.
Make yourself comfortable with a hot flask of your favorite beverage. Keep warm but not so snug that you fall asleep!
Meteor watching is a lot like fishing. Sometimes you catch a good number of them, and sometimes you don’t.
This section is by the late, great Don Machholz (1952-2022), who discovered 12 comets …
The object responsible for the Eta Aquariid meteor shower – that is, its parent comet – is the famous Halley’s comet. This comet is in a retrograde orbit around the sun. That means it runs around the sun in the opposite direction from Earth and all the other planets. As a result, we pass near its path twice, one time along the outbound portion of the comet’s orbit. That happens every early May, causing the Eta Aquariid meteor shower. The other time is along the inbound portion of the comet’s orbit, and that passage causes the Orionid meteor shower in late October of each year.
Halley’s comet orbits the sun on an average of every 76 years (the range is from 74 through 79 years due to perturbations of the planets). So, in most years, the comet is nowhere near when we sweep through its orbit, and when debris left behind by the comet enters our atmosphere to create Halley’s two meteor showers.
In December of 2023, the comet reached its farthest point from the sun, which binds it in orbit. Then – pulled inexorably by the sun’s gravity – it curved around and is heading back toward the inner solar system again. Halley’s comet will be back in 2061.
While waiting for Halley’s comet to return, watch for the next best thing: the Eta Aquariid meteor shower in early May.
Halley’s comet, the parent of the May Eta Aquariid and October Orionid meteor showers. Dust from this comet will light the night as Eta Aquariid meteors on the morning of May 5. Image via NASA.
Eta Aquariid meteor shower photos from EarthSky’s community
View at EarthSky Community Photos. | Christoph Stopka captured some Eta Aquariid meteors on May 5, 2024, near Westcliffe, Colorado, and said: “I kept my camera pointed towards the Milky Way, hoping for a meteor streaking by. And finally, it was showtime: I saw a greenish flash to the left of the Milky Way and knew instantly I had a winner! Sure enough, when I checked my last 15 seconds exposure on the screen of the camera, I could clearly identify a good size meteor in the image. But to my big surprise, I saw that there was actually a SECOND, smaller meteor below the one I had noticed!” Thank you, Christoph!View at EarthSky Community Photos. | Eliot Herman in Tucson, Arizona, captured this photo of an Eta Aquariid meteor on May 5, 2021. He wrote: “1:48 am on peak night. The radiant is still below the horizon, resulting in this long-trail meteor with the beautiful green, typical of Halley’s comet-derived meteors. My backyard view.” Thank you, Eliot!View at EarthSky Community Photos. | Mary Jo Machnica in Hamburg, New York, captured this photo of an Eta Aquariid on May 6, 2021. She wrote: “I knew that the Eta Aquariids meteor shower was going to peak this morning. I knew there was going to be a ton of light pollution. But, it didn’t matter. I just needed to be under the stars. Needing to feel small. Getting there right before 3 a.m. I set up my camera. Super damp out! Glad I have my lens warmer. With everything set up. I just keep taking photo after photo hoping to capture a glimpse of a meteor. I see a couple meteors with my eyes, but they don’t show up in the photo … That’s ok. I keep snapping away.” Thank you!
Bottom line: May’s Eta Aquariid meteor shower is best in 2026 on the morning of May 5. Be sure to watch in the hours before dawn. Find a way to block out the waning gibbous moon.
The radiant point of the Eta Aquariid meteor shower is near the star Eta Aquarii in the constellation Aquarius the Water Bearer. The radiant rises in the wee hours after midnight and is still climbing toward its highest point at dawn. That highest point is in the south as viewed from the Northern Hemisphere, closer to overhead for the Southern Hemisphere. That’s why the Southern Hemisphere sees more meteors (the radiant is higher up), and it’s why – for all of us around the globe – the hours before dawn are best for this shower.
May 2026 meteors … the Eta Aquariids
When to watch: The best morning to watch is May 5, 2026, in the hours before dawn. The American Meteor Society is listing 3:51 UTC on May 5 as the shower’s predicted** peak time. The fact is that the peak of this shower stretches out over several days. So you can expect elevated numbers of meteors a few days before and after the peak time. The mornings of both May 4 and May 6 are also good times to watch! Nearest moon phase: The last quarter moon will fall at 21:10 UTC on May 9. So, there will be a waning gibbous moon in the post-midnight sky, that sets after sunrise. So the sky before dawn on the mornings around the predicted peak for the 2025 Eta Aquariids will compete with a bright gibbous moon. Find a way to block out the moon for a better view of the sky. The radiant: will rise in the wee hours, climbing toward its highest point at dawn. That’s why the hours before dawn will be the best time to watch this shower. Duration of shower: April 15 to May 27. This time period is when we’re passing through the Eta Aquariid meteor stream in space! Expected meteors at peak, under ideal conditions: The zenithal hourly rate (ZHR) of this shower (the rate at the shower’s peak, under a dark sky, with no moon, when the radiant is high in the sky) is 60. In 2026, a waning gibbous moon will severely affect this shower, reducing hourly rates. And be aware that the shower is best for latitudes like those in the southern half of the U.S. or even farther south, in the Southern Hemisphere. These are swift meteors that produce a high percentage of persistent trains. Note: The Eta Aquariids’ radiant will be on the ecliptic, which will ride low in the sky on spring mornings as seen from far northerly latitudes. This shower favors more southerly latitudes (like those in the southern U.S. or the Southern Hemisphere), where the radiant appears higher in the morning sky. It’s often the Southern Hemisphere’s best meteor shower of the year.
If you trace the paths of the Eta Aquariid meteors backward, they all seem to radiate from a point in the constellation Aquarius the Water Bearer. This point on the sky’s dome is called the radiant of the meteor shower. It nearly aligns with the faint star Eta Aquarii, and the meteor shower takes its name from this star.
Eta Aquarii is one of the four stars making up the Y-shaped Water Jarasterism in the northern part of Aquarius. If you can find the Water Jar in the constellation Aquarius, you’ve located the radiant point for the Eta Aquariid meteors. The alignment of the radiant and the star is, of course, coincidental. Eta Aquarii is some 170 light-years away – trillions upon trillions of miles away – while the Eta Aquariid meteors burn up nearby – only 60 miles (100 km) above Earth’s surface.
Meteor shower radiants are sometimes misunderstood by casual meteor-watchers. You don’t need to know where they are to watch a meteor shower. That’s because the meteors fly every way across the sky, in front of numerous constellations. However, the higher a shower’s radiant appears in your sky, the more meteors you’re likely to see. For the Eta Aquariids, the radiant soars highest in the nighttime sky just before dawn. That’s one of the reasons why you can expect to see the most meteors in the wee morning hours.
How to view a meteor shower
As with all meteors in annual showers, no special equipment is required to watch the Eta Aquariids. But a little luck always helps.
Find a dark, open sky away from artificial lights, and sprawl out on a reclining lawn chair.
Make yourself comfortable with a hot flask of your favorite beverage. Keep warm but not so snug that you fall asleep!
Meteor watching is a lot like fishing. Sometimes you catch a good number of them, and sometimes you don’t.
This section is by the late, great Don Machholz (1952-2022), who discovered 12 comets …
The object responsible for the Eta Aquariid meteor shower – that is, its parent comet – is the famous Halley’s comet. This comet is in a retrograde orbit around the sun. That means it runs around the sun in the opposite direction from Earth and all the other planets. As a result, we pass near its path twice, one time along the outbound portion of the comet’s orbit. That happens every early May, causing the Eta Aquariid meteor shower. The other time is along the inbound portion of the comet’s orbit, and that passage causes the Orionid meteor shower in late October of each year.
Halley’s comet orbits the sun on an average of every 76 years (the range is from 74 through 79 years due to perturbations of the planets). So, in most years, the comet is nowhere near when we sweep through its orbit, and when debris left behind by the comet enters our atmosphere to create Halley’s two meteor showers.
In December of 2023, the comet reached its farthest point from the sun, which binds it in orbit. Then – pulled inexorably by the sun’s gravity – it curved around and is heading back toward the inner solar system again. Halley’s comet will be back in 2061.
While waiting for Halley’s comet to return, watch for the next best thing: the Eta Aquariid meteor shower in early May.
Halley’s comet, the parent of the May Eta Aquariid and October Orionid meteor showers. Dust from this comet will light the night as Eta Aquariid meteors on the morning of May 5. Image via NASA.
Eta Aquariid meteor shower photos from EarthSky’s community
View at EarthSky Community Photos. | Christoph Stopka captured some Eta Aquariid meteors on May 5, 2024, near Westcliffe, Colorado, and said: “I kept my camera pointed towards the Milky Way, hoping for a meteor streaking by. And finally, it was showtime: I saw a greenish flash to the left of the Milky Way and knew instantly I had a winner! Sure enough, when I checked my last 15 seconds exposure on the screen of the camera, I could clearly identify a good size meteor in the image. But to my big surprise, I saw that there was actually a SECOND, smaller meteor below the one I had noticed!” Thank you, Christoph!View at EarthSky Community Photos. | Eliot Herman in Tucson, Arizona, captured this photo of an Eta Aquariid meteor on May 5, 2021. He wrote: “1:48 am on peak night. The radiant is still below the horizon, resulting in this long-trail meteor with the beautiful green, typical of Halley’s comet-derived meteors. My backyard view.” Thank you, Eliot!View at EarthSky Community Photos. | Mary Jo Machnica in Hamburg, New York, captured this photo of an Eta Aquariid on May 6, 2021. She wrote: “I knew that the Eta Aquariids meteor shower was going to peak this morning. I knew there was going to be a ton of light pollution. But, it didn’t matter. I just needed to be under the stars. Needing to feel small. Getting there right before 3 a.m. I set up my camera. Super damp out! Glad I have my lens warmer. With everything set up. I just keep taking photo after photo hoping to capture a glimpse of a meteor. I see a couple meteors with my eyes, but they don’t show up in the photo … That’s ok. I keep snapping away.” Thank you!
Bottom line: May’s Eta Aquariid meteor shower is best in 2026 on the morning of May 5. Be sure to watch in the hours before dawn. Find a way to block out the waning gibbous moon.
In this view from January 8, 2025, the Palisades Fire threatens houses along the Pacific Coast in California. A new study says western US wildfires have become less frequent over the past 30 years. However, the wildfires are getting larger. Image via CAL FIRE.
Wildfires in the western U.S. are becoming less frequent, a new study says.
But the wildfires that do occur are getting worse. They’re burning larger areas and causing more damage.
Humans appear to be driving these changes. Human-driven climate change is making wildfires more destructive, while human behavioural change seems to be making them less frequent.
Western US wildfires less frequent but more massive
First, the good news: The number of wildfires in the western U.S. has gone down. Wildfires in this region are down about 28% over the past 30 years. And a large part of that is due to a 40% decline in fires accidentally started by humans.
Now, the bad news: The wildfires that do occur in the West are having a larger impact. They are burning larger areas, and so fire damages are increasing. The cause? Human-driven climate change making these regions hotter and drier.
These are the findings of a new study published on April 30, 2026, examining fire frequency and human influence in the western United States.
The researchers also identified a pattern relating to human habitation. In areas with lots of people, there are fewer fires. Meanwhile, in areas with fewer people, the frequency of fires goes up as the population density of that region rises. Unfortunately, there are also exceptions to these population trends. Los Angeles, Phoenix and Denver are seeing more frequent fires despite their high population densities.
The researchers say studying human demographics and wildfire frequency could help predict future patterns. But it’s still early to draw too many conclusions. Gavin Madakumbura, an atmospheric and oceanic scientist at UCLA and leader of the study, said:
It would be premature to talk about informing fire management [based on] these results, but the main implication is that we can incorporate these results into projections of future fire activity.
Even though the total number of wildfires in the western U.S. has gone down, it might not seem like it. That’s because the impacts of the wildfires are going up. The fires may be fewer in number, but they are burning more land. Between 1992 and 2020, 4% more land burned each year. Case in point: In 2020, wildfires across California, Oregon and Washington burned more than 9 million acres. That’s larger than the state of Maryland.
But in the new study, the researchers did find that the number of fires per year in the West is going down. In 1992, they counted 25,000 fires. And by 2020, it was down to 18,000 fires. So that’s 305 fewer fires each year. Their study looked at 11 western states, from Montana, Wyoming, Colorado, New Mexico and westward.
This was the view from the GOES-17 satellite on September 9, 2020. That year, wildfires burned more than 9 million acres in the western U.S. Image via NWS.
What is the role of humans in these fires?
The decline of human-started fires was not consistent across all states. While California and Arizona saw fewer fires started by people, Wyoming saw more. Part of this could be due to public resources.
The researchers looked at a number of factors, including changes in population density and fire protection and management expenditures for each state. The higher the population density, the more the state spent on fire protection. For example, California spends 7 billion dollars more a year on fire protection compared to Wyoming.
Scientists call the link between population density and fires pyric transition. As the press release explained:
In sparsely populated regions, the idea goes, adding more people leads to more fires accidentally sparked by human activity. But past a certain threshold of population density, more people also means more coordinated fire prevention and public awareness efforts to tackle the rising risk. This, coupled with the fragmented, patchwork nature of more populated landscapes, can end up making fires less frequent.
So the scientists are seeing a correlation between population density and fires. But is there a causation as well? Madakumbura said:
We know that with increasing human activity, we get more accidental human ignitions. But at the same time, a lot of regions are spending so much money on fire prevention and fire awareness, so we should see this in the data. The data definitely seem to indicate that this is a possible causative relationship.
What about the big-city outliers?
Los Angeles, Phoenix and Denver have some of the larger population centers in the western U.S., but they still have frequent fires. But it could be a difference in fire reporting practices, said Madakumbura. These areas might have more reports of small fires, whereas a lower-population area might not have these reports. Sparsely populated areas might focus more on wildland fires.
The role of climate change
So why is a larger area burning even though there are fewer fires? Madakumbura said human-driven climate warming is to blame. As these regions got hotter and drier, the conditions encourage the development of larger fires.
But climate change may both be triggering a rise in fires and suppression as well. As the West grapples with the threat of fire due to the heat and low humidity, places with adequate resources increase their prevention efforts.
So while human-caused climate change is a factor in fires, the human demographics of an area also appears to be a factor. The researchers are hoping to help predict future fire patterns more accurately by looking at all possible factors. Madakumbura concluded:
Even though we have been able to reduce the number of fires through fire preparedness, fire awareness, and spending a lot of money on protective measures, there is a disconnect. We haven’t been able to reduce the damages.
Bottom line: Researchers looked at western U.S. wildfires over the past 30 years and found that while they are becoming less frequent, the fires that pop up are larger and more damaging.
In this view from January 8, 2025, the Palisades Fire threatens houses along the Pacific Coast in California. A new study says western US wildfires have become less frequent over the past 30 years. However, the wildfires are getting larger. Image via CAL FIRE.
Wildfires in the western U.S. are becoming less frequent, a new study says.
But the wildfires that do occur are getting worse. They’re burning larger areas and causing more damage.
Humans appear to be driving these changes. Human-driven climate change is making wildfires more destructive, while human behavioural change seems to be making them less frequent.
Western US wildfires less frequent but more massive
First, the good news: The number of wildfires in the western U.S. has gone down. Wildfires in this region are down about 28% over the past 30 years. And a large part of that is due to a 40% decline in fires accidentally started by humans.
Now, the bad news: The wildfires that do occur in the West are having a larger impact. They are burning larger areas, and so fire damages are increasing. The cause? Human-driven climate change making these regions hotter and drier.
These are the findings of a new study published on April 30, 2026, examining fire frequency and human influence in the western United States.
The researchers also identified a pattern relating to human habitation. In areas with lots of people, there are fewer fires. Meanwhile, in areas with fewer people, the frequency of fires goes up as the population density of that region rises. Unfortunately, there are also exceptions to these population trends. Los Angeles, Phoenix and Denver are seeing more frequent fires despite their high population densities.
The researchers say studying human demographics and wildfire frequency could help predict future patterns. But it’s still early to draw too many conclusions. Gavin Madakumbura, an atmospheric and oceanic scientist at UCLA and leader of the study, said:
It would be premature to talk about informing fire management [based on] these results, but the main implication is that we can incorporate these results into projections of future fire activity.
Even though the total number of wildfires in the western U.S. has gone down, it might not seem like it. That’s because the impacts of the wildfires are going up. The fires may be fewer in number, but they are burning more land. Between 1992 and 2020, 4% more land burned each year. Case in point: In 2020, wildfires across California, Oregon and Washington burned more than 9 million acres. That’s larger than the state of Maryland.
But in the new study, the researchers did find that the number of fires per year in the West is going down. In 1992, they counted 25,000 fires. And by 2020, it was down to 18,000 fires. So that’s 305 fewer fires each year. Their study looked at 11 western states, from Montana, Wyoming, Colorado, New Mexico and westward.
This was the view from the GOES-17 satellite on September 9, 2020. That year, wildfires burned more than 9 million acres in the western U.S. Image via NWS.
What is the role of humans in these fires?
The decline of human-started fires was not consistent across all states. While California and Arizona saw fewer fires started by people, Wyoming saw more. Part of this could be due to public resources.
The researchers looked at a number of factors, including changes in population density and fire protection and management expenditures for each state. The higher the population density, the more the state spent on fire protection. For example, California spends 7 billion dollars more a year on fire protection compared to Wyoming.
Scientists call the link between population density and fires pyric transition. As the press release explained:
In sparsely populated regions, the idea goes, adding more people leads to more fires accidentally sparked by human activity. But past a certain threshold of population density, more people also means more coordinated fire prevention and public awareness efforts to tackle the rising risk. This, coupled with the fragmented, patchwork nature of more populated landscapes, can end up making fires less frequent.
So the scientists are seeing a correlation between population density and fires. But is there a causation as well? Madakumbura said:
We know that with increasing human activity, we get more accidental human ignitions. But at the same time, a lot of regions are spending so much money on fire prevention and fire awareness, so we should see this in the data. The data definitely seem to indicate that this is a possible causative relationship.
What about the big-city outliers?
Los Angeles, Phoenix and Denver have some of the larger population centers in the western U.S., but they still have frequent fires. But it could be a difference in fire reporting practices, said Madakumbura. These areas might have more reports of small fires, whereas a lower-population area might not have these reports. Sparsely populated areas might focus more on wildland fires.
The role of climate change
So why is a larger area burning even though there are fewer fires? Madakumbura said human-driven climate warming is to blame. As these regions got hotter and drier, the conditions encourage the development of larger fires.
But climate change may both be triggering a rise in fires and suppression as well. As the West grapples with the threat of fire due to the heat and low humidity, places with adequate resources increase their prevention efforts.
So while human-caused climate change is a factor in fires, the human demographics of an area also appears to be a factor. The researchers are hoping to help predict future fire patterns more accurately by looking at all possible factors. Madakumbura concluded:
Even though we have been able to reduce the number of fires through fire preparedness, fire awareness, and spending a lot of money on protective measures, there is a disconnect. We haven’t been able to reduce the damages.
Bottom line: Researchers looked at western U.S. wildfires over the past 30 years and found that while they are becoming less frequent, the fires that pop up are larger and more damaging.
This is the spot where a Falcon 9 upper stage rocket body will collide with the moon on August 5, 2026. The spent rocket will hit the moon at 5,400 mph (8,700 kph). Image via Bill Gray. Used with permission.
Back on January 15, 2025, a Falcon 9 rocket launched two missions toward the moon: Blue Ghost and Hakuto-R. After the upper stage of the Falcon 9 rocket completed its boosting mission, it became just another piece of space junk. But now, says Bill Gray, a prolific tracker of near-Earth objects, the Falcon 9 is on a collision course with the moon.
Gray estimates the upper stage will hit the moon at 1:44 a.m. CDT (6:44 UTC) on August 5, 2026. As Gray said:
It doesn’t present any danger to anyone, though it does highlight a certain carelessness about how leftover space hardware (space junk) is disposed of.
Will we be able to see the impact?
The moon will be close to last quarter phase on August 5, 2026. By 1:44 a.m. CDT, those in the Central Time Zone will be able to see the moon, as it will have already risen in the east. Saturn will be nearby. Check Stellarium to see if the moon will be above the horizon at the time of impact if you’re further west. The timing will favor people in the eastern half of the U.S. and Canada, plus much of South America.
So where will the rocket hit? Right now, Gray said he estimates the impact will occur near the edge, or limb, of the moon, close to the Einstein crater.
However, the chances are we won’t be able to see the impact from Earth. Darn. Although the Einstein crater should (barely) be visible, the impact will likely be too small to see from so great a distance. However, after the impact, NASA’s Lunar Reconnaissance Orbiter might be able to get an image of the resulting crater. It’s happened before.
Previous lunar impact
Back in 2022, Bill Gray also predicted a rocket impact with the moon. There was a little confusion about where the rocket came from, but the space junk did indeed hit the moon on March 4, 2022. And it left a mark, too. NASA’s Lunar Reconnaissance Orbiter took an image of the aftermath.
A rocket body struck the moon on March 4, 2022, near Hertzsprung crater. It created a double crater roughly 100 feet (30 meters) wide at its longest. Image via NASA/ Goddard/ Arizona State University.
A speeding object
Gray estimates the space junk will hit the moon at about 2.43 kilometers (1.51 miles) a second. That equates to 5,400 miles (8,700 kilometers) an hour. Because the moon has no real atmosphere, there will be nothing to slow it down.
Tracking the Falcon 9 upper stage
There have been hundreds of Falcon 9 launches. Usually, the spent rocket bodies orbit closely to Earth and eventually reenter our atmosphere. But some have gone on to orbit the sun.
This upper stage rocket has spent most of its time farther out than average, around the distance of the moon. Asteroid surveys pick up objects like this as they scan for dangerous space rocks. As Gray said:
The asteroid surveys would actually prefer not to observe space junk. Time spent observing junk is time not spent finding rocks. But both the rocks and the high-altitude space junk are slowly moving points of light in their images; they aren’t easy to distinguish. So the asteroid surveys find this sort of junk whether they want to or not.
Gray provides software tools for astronomers that help them distinguish between space rocks and space junk. He also computes orbits for high-orbiting objects the military doesn’t track. And he’s been tracking this piece of space junk for months. He’s known since September 2025 that the upper stage was likely on a collision course with the moon. And as he told EarthSky, he wasn’t surprised:
I’ve been checking for such possible impacts for about 20 years, ever since we started having many large bits of junk in orbits that could hit the moon. In a way, the only real surprise is that only two objects have hit the moon.
Rocket will hit the moon despite tiny pushes from sunlight
Over the past months he’s continued to track the object. The reason it can change course a tiny bit is due to the gentle push of sunlight on objects. And that little bit of push is tricky to track. As Gray said:
As an object tumbles, it may catch more or less sunlight, and may reflect some of it sideways.
But, as Gray told EarthSky:
I was reasonably sure a month or two later, but was in no rush to say anything about it. I figured I’d wait until the impact location was well established. So it was something of a gradual process, with no ‘Aha! It’s gonna hit!’ moment.
Not a lot of tracking farther from Earth
Gray told EarthSky:
I am an astronomer working under contract with both asteroid and artificial object observers. I started out doing this for natural objects (asteroids, comets, moons of other planets) about 30 years ago. A few years later, the asteroid surveys started to notice the occasional artificial object and asked me if I could find orbits for them as well.
And as Gray explains on his website, various countries carefully track objects in low-Earth orbit because there are so many pieces of debris with risks of collision with military and science satellites. Farther from Earth, there is less tracking. Or, as Gray said:
Generally speaking, high-altitude junk goes ignored. (Except, it appears, by me.)
Gray works with asteroid hunters. As he said:
My ‘day work’ is for the asteroid-hunting community … Most artificial objects are close to the Earth and move fast enough that there is no risk of mistaking them for an asteroid. But there are about a dozen ‘high-flying’ objects that can move slowly enough to look like a rock, at least briefly. For about 15 or 20 years now, I’ve taken these observations and computed orbits. Then, when the surveys find such objects, they can fairly quickly say ‘Never mind; it’s not a rock; it’s just another nuisance artificial object,’ and go back to looking for actual rocks.
Bottom line: A Falcon 9 rocket will hit the moon on August 5, 2026. How fast will it be going? Will we be able to see it? Answers here.
This is the spot where a Falcon 9 upper stage rocket body will collide with the moon on August 5, 2026. The spent rocket will hit the moon at 5,400 mph (8,700 kph). Image via Bill Gray. Used with permission.
Back on January 15, 2025, a Falcon 9 rocket launched two missions toward the moon: Blue Ghost and Hakuto-R. After the upper stage of the Falcon 9 rocket completed its boosting mission, it became just another piece of space junk. But now, says Bill Gray, a prolific tracker of near-Earth objects, the Falcon 9 is on a collision course with the moon.
Gray estimates the upper stage will hit the moon at 1:44 a.m. CDT (6:44 UTC) on August 5, 2026. As Gray said:
It doesn’t present any danger to anyone, though it does highlight a certain carelessness about how leftover space hardware (space junk) is disposed of.
Will we be able to see the impact?
The moon will be close to last quarter phase on August 5, 2026. By 1:44 a.m. CDT, those in the Central Time Zone will be able to see the moon, as it will have already risen in the east. Saturn will be nearby. Check Stellarium to see if the moon will be above the horizon at the time of impact if you’re further west. The timing will favor people in the eastern half of the U.S. and Canada, plus much of South America.
So where will the rocket hit? Right now, Gray said he estimates the impact will occur near the edge, or limb, of the moon, close to the Einstein crater.
However, the chances are we won’t be able to see the impact from Earth. Darn. Although the Einstein crater should (barely) be visible, the impact will likely be too small to see from so great a distance. However, after the impact, NASA’s Lunar Reconnaissance Orbiter might be able to get an image of the resulting crater. It’s happened before.
Previous lunar impact
Back in 2022, Bill Gray also predicted a rocket impact with the moon. There was a little confusion about where the rocket came from, but the space junk did indeed hit the moon on March 4, 2022. And it left a mark, too. NASA’s Lunar Reconnaissance Orbiter took an image of the aftermath.
A rocket body struck the moon on March 4, 2022, near Hertzsprung crater. It created a double crater roughly 100 feet (30 meters) wide at its longest. Image via NASA/ Goddard/ Arizona State University.
A speeding object
Gray estimates the space junk will hit the moon at about 2.43 kilometers (1.51 miles) a second. That equates to 5,400 miles (8,700 kilometers) an hour. Because the moon has no real atmosphere, there will be nothing to slow it down.
Tracking the Falcon 9 upper stage
There have been hundreds of Falcon 9 launches. Usually, the spent rocket bodies orbit closely to Earth and eventually reenter our atmosphere. But some have gone on to orbit the sun.
This upper stage rocket has spent most of its time farther out than average, around the distance of the moon. Asteroid surveys pick up objects like this as they scan for dangerous space rocks. As Gray said:
The asteroid surveys would actually prefer not to observe space junk. Time spent observing junk is time not spent finding rocks. But both the rocks and the high-altitude space junk are slowly moving points of light in their images; they aren’t easy to distinguish. So the asteroid surveys find this sort of junk whether they want to or not.
Gray provides software tools for astronomers that help them distinguish between space rocks and space junk. He also computes orbits for high-orbiting objects the military doesn’t track. And he’s been tracking this piece of space junk for months. He’s known since September 2025 that the upper stage was likely on a collision course with the moon. And as he told EarthSky, he wasn’t surprised:
I’ve been checking for such possible impacts for about 20 years, ever since we started having many large bits of junk in orbits that could hit the moon. In a way, the only real surprise is that only two objects have hit the moon.
Rocket will hit the moon despite tiny pushes from sunlight
Over the past months he’s continued to track the object. The reason it can change course a tiny bit is due to the gentle push of sunlight on objects. And that little bit of push is tricky to track. As Gray said:
As an object tumbles, it may catch more or less sunlight, and may reflect some of it sideways.
But, as Gray told EarthSky:
I was reasonably sure a month or two later, but was in no rush to say anything about it. I figured I’d wait until the impact location was well established. So it was something of a gradual process, with no ‘Aha! It’s gonna hit!’ moment.
Not a lot of tracking farther from Earth
Gray told EarthSky:
I am an astronomer working under contract with both asteroid and artificial object observers. I started out doing this for natural objects (asteroids, comets, moons of other planets) about 30 years ago. A few years later, the asteroid surveys started to notice the occasional artificial object and asked me if I could find orbits for them as well.
And as Gray explains on his website, various countries carefully track objects in low-Earth orbit because there are so many pieces of debris with risks of collision with military and science satellites. Farther from Earth, there is less tracking. Or, as Gray said:
Generally speaking, high-altitude junk goes ignored. (Except, it appears, by me.)
Gray works with asteroid hunters. As he said:
My ‘day work’ is for the asteroid-hunting community … Most artificial objects are close to the Earth and move fast enough that there is no risk of mistaking them for an asteroid. But there are about a dozen ‘high-flying’ objects that can move slowly enough to look like a rock, at least briefly. For about 15 or 20 years now, I’ve taken these observations and computed orbits. Then, when the surveys find such objects, they can fairly quickly say ‘Never mind; it’s not a rock; it’s just another nuisance artificial object,’ and go back to looking for actual rocks.
Bottom line: A Falcon 9 rocket will hit the moon on August 5, 2026. How fast will it be going? Will we be able to see it? Answers here.
