View at EarthSky Community Photos. | Ross Stone in California captured the Death Valley superbloom on March 16, 2026. Ross wrote: ” field of desert gold wildflowers in full bloom near Badwater in Death Valley National Park.” Thank you, Ross!
Death Valley National Park – the hottest and driest place in North America – is having a superbloom.
The park normally sees about 2 inches (5 cm) of rain in a year. But it had more than a year’s worth of rain (2.5 inches, or 6 cm) between November 2025 and January 2026.
The extra rain woke up dormant seeds. It’s given us the first superbloom in Death Valley since 2016.
As of mid-March, the superbloom is past peak, but there are still flowers to be seen! The National Park Service (NPS) announced current bloom locations (March 16, 2026):
Badwater Rd (between CA190 and Sidewinder Canyon): Desert Gold, Phacelia, Mojave Star. Some flowers remain, most are setting seed
Panamint Valley: occasional Desert Gold patches; brittlebush by Father Crowley Vista
In early March, the NPS said:
We are having the best bloom year since 2016 and many sprouts have not yet flowered. The showy yellow desert gold is one of the most prominent flowers, but there are a large variety of other species blooming as well. Low-elevation flowers are blooming throughout the park and will likely persist until mid-late March, depending on the weather. Higher elevations will have blooms April-June.
The Death Valley superbloom is happening now. It’s the best display of spring wildflowers since 2016. Image via National Park Service.
The Death Valley superbloom is underway! ? Colorful flowers are blanketing parts of the hottest place in North America. Park officials say it’s the best superbloom since 2016.
Superblooms don’t happen on a schedule, but they occur about once a decade. The past superblooms have been in 2016, 2005 and 1998. The extra abundance of flowers can also attract more pollinators, so keep an eye out for more bees, butterflies, birds and more.
This rare and short-lived phenomenon is important to the desert ecosystem. The NPS said:
In Death Valley National park, most of the showy desert wildflowers are annuals, also referred to as ephemerals because they are short-lived. Oddly enough, this limited lifespan ensures survival here. Rather than struggle to stay alive during the desert’s most extreme conditions, annual wildflowers lie dormant as seeds. When enough rain finally does fall, the seeds quickly sprout, grow, bloom and go back to seed again before the dryness and heat returns. By blooming en masse during good years, wildflowers can attract large numbers of pollinators such as butterflies, moths, bees and hummingbirds that might not otherwise visit Death Valley.
View larger. | Death Valley wildflowers. Posted by the National Park Service in March 2026.View at EarthSky Community Photos. | Ross Stone captured a rare sight of water in the basin at Death Valley National Park on March 15, 2026. Ross wrote: “Even though the temperatures are quickly rising in Death Valley, there is still a good amount of water in Lake Manly … Which makes it a fabulous place to people watch and take some excellent landscape photographs.” Thank you, Ross!
Are you planning to visit the park this spring?
Here’s what you need to know if you’re planning to visit the park this spring. First, be patient! There will be many others visiting also, but it’s a huge park with space for everyone. Traffic might be slow, but you will eventually get to that picture-perfect site.
To keep up-to-date on what’s blooming and where, visit the NPS website.
And, of course, don’t pick the wildflowers! Capture them only with your camera. And if you get a great photo, submit it to us!
2026 Death Valley superbloom
NATURE's WAY… Fighting Death With Color Energy! ??Death Valley Sees Its Most Spectacular Super Bloom In A Decade…
1/x“Wildflowers, South Death Valley” — A flower-covered landscape.Is this a so-called “super bloom” year…more: gdanmitchell.com/2026/03/07/w…#deathvalley #wildflowers #superbloom #photo #photoOfTheDay #lensCulture #landscapePhotography #photographyLovers #naturePhotography #fineArtPhotography
Bottom line: A Death Valley superbloom erupted this spring. This rare event only happens about every decade. Read more about what flowers are blooming and where in Death Valley National Park.
View at EarthSky Community Photos. | Ross Stone in California captured the Death Valley superbloom on March 16, 2026. Ross wrote: ” field of desert gold wildflowers in full bloom near Badwater in Death Valley National Park.” Thank you, Ross!
Death Valley National Park – the hottest and driest place in North America – is having a superbloom.
The park normally sees about 2 inches (5 cm) of rain in a year. But it had more than a year’s worth of rain (2.5 inches, or 6 cm) between November 2025 and January 2026.
The extra rain woke up dormant seeds. It’s given us the first superbloom in Death Valley since 2016.
As of mid-March, the superbloom is past peak, but there are still flowers to be seen! The National Park Service (NPS) announced current bloom locations (March 16, 2026):
Badwater Rd (between CA190 and Sidewinder Canyon): Desert Gold, Phacelia, Mojave Star. Some flowers remain, most are setting seed
Panamint Valley: occasional Desert Gold patches; brittlebush by Father Crowley Vista
In early March, the NPS said:
We are having the best bloom year since 2016 and many sprouts have not yet flowered. The showy yellow desert gold is one of the most prominent flowers, but there are a large variety of other species blooming as well. Low-elevation flowers are blooming throughout the park and will likely persist until mid-late March, depending on the weather. Higher elevations will have blooms April-June.
The Death Valley superbloom is happening now. It’s the best display of spring wildflowers since 2016. Image via National Park Service.
The Death Valley superbloom is underway! ? Colorful flowers are blanketing parts of the hottest place in North America. Park officials say it’s the best superbloom since 2016.
Superblooms don’t happen on a schedule, but they occur about once a decade. The past superblooms have been in 2016, 2005 and 1998. The extra abundance of flowers can also attract more pollinators, so keep an eye out for more bees, butterflies, birds and more.
This rare and short-lived phenomenon is important to the desert ecosystem. The NPS said:
In Death Valley National park, most of the showy desert wildflowers are annuals, also referred to as ephemerals because they are short-lived. Oddly enough, this limited lifespan ensures survival here. Rather than struggle to stay alive during the desert’s most extreme conditions, annual wildflowers lie dormant as seeds. When enough rain finally does fall, the seeds quickly sprout, grow, bloom and go back to seed again before the dryness and heat returns. By blooming en masse during good years, wildflowers can attract large numbers of pollinators such as butterflies, moths, bees and hummingbirds that might not otherwise visit Death Valley.
View larger. | Death Valley wildflowers. Posted by the National Park Service in March 2026.View at EarthSky Community Photos. | Ross Stone captured a rare sight of water in the basin at Death Valley National Park on March 15, 2026. Ross wrote: “Even though the temperatures are quickly rising in Death Valley, there is still a good amount of water in Lake Manly … Which makes it a fabulous place to people watch and take some excellent landscape photographs.” Thank you, Ross!
Are you planning to visit the park this spring?
Here’s what you need to know if you’re planning to visit the park this spring. First, be patient! There will be many others visiting also, but it’s a huge park with space for everyone. Traffic might be slow, but you will eventually get to that picture-perfect site.
To keep up-to-date on what’s blooming and where, visit the NPS website.
And, of course, don’t pick the wildflowers! Capture them only with your camera. And if you get a great photo, submit it to us!
2026 Death Valley superbloom
NATURE's WAY… Fighting Death With Color Energy! ??Death Valley Sees Its Most Spectacular Super Bloom In A Decade…
1/x“Wildflowers, South Death Valley” — A flower-covered landscape.Is this a so-called “super bloom” year…more: gdanmitchell.com/2026/03/07/w…#deathvalley #wildflowers #superbloom #photo #photoOfTheDay #lensCulture #landscapePhotography #photographyLovers #naturePhotography #fineArtPhotography
Bottom line: A Death Valley superbloom erupted this spring. This rare event only happens about every decade. Read more about what flowers are blooming and where in Death Valley National Park.
Pyxis the Compass is considered a constellation of the Southern Hemisphere skies. But northerners at southerly latitudes can see it, too, on March evenings.
March is a good month to view the constellation Pyxis the Compass. That’s assuming you’re far enough south on Earth’s globe. Pyxis is one of the 14 constellations that the French astronomer Nicolas-Louis de Lacaille created in the 1700s. It represents a ship’s compass. Conveniently, this ship’s compass lies on our sky’s dome next to the three constellations, Puppis, Vela and Carina, elements that made up the former constellation of Argo Navis. That was the great starry Ship that once sailed the southern skies.
By the way, don’t confuse Pyxis the Compass with Circinus. That’s a different constellation that represents a drawing compass.
Pyxis lies southeast of Canis Major the Greater Dog, with its very bright star Sirius. From Sirius, look toward the east to the quiet part of the sky where Pyxis resides. See the photo below.
The Alpha and Beta stars of Pyxis lie in the southern part of the constellation. More specifically, Alpha Pyxidis is magnitude 3.68 and lies 845 light-years away. Likewise, just over 2 degrees to the south is Beta Pyxidis at magnitude 3.97 and lying 388 light-years away.
In addition, both Alpha and Beta have faint star clusters lying a half degree to the northwest. Alpha’s star cluster is NGC 2658 at magnitude 9.2. And Beta’s star cluster is NGC 2635 at magnitude 11.2. So with this in mind, you’ll want binoculars or a telescope to track them down. In particular, NGC 2635 is a real challenge.
However, there are two other deep-sky targets in Pyxis that are somewhat brighter. First, there’s NGC 2627. It’s a magnitude 8.4 star cluster lying 3 1/2 degrees northwest of Alpha, or just 1/2 degree southwest of Zeta Pyxidis, a magnitude 4.86 star. Then, the second one lies in the southeast corner of the constellation. It’s NGC 2818, a planetary nebula shining at magnitude 11.6. Which we can see in the glorious Hubble photo, below.
The stars of Pyxis are difficult to see from a location with light pollution. For instance, Pyxis the Compass’s brightest star is a faint magnitude 3.68. Image via International Astronomical Union/ Wikimedia Commons (CC BY 3.0).The Hubble Space Telescope took this shot of the planetary nebula NGC 2818 in Pyxis in 2009. Image via NASA.
Bottom line: Pyxis the Compass is a constellation lying in southern skies. But Northern Hemisphere viewers can get a glimpse of in March. Nicolas-Louis de Lacaille created the constellation in the 1700s.
Pyxis the Compass is considered a constellation of the Southern Hemisphere skies. But northerners at southerly latitudes can see it, too, on March evenings.
March is a good month to view the constellation Pyxis the Compass. That’s assuming you’re far enough south on Earth’s globe. Pyxis is one of the 14 constellations that the French astronomer Nicolas-Louis de Lacaille created in the 1700s. It represents a ship’s compass. Conveniently, this ship’s compass lies on our sky’s dome next to the three constellations, Puppis, Vela and Carina, elements that made up the former constellation of Argo Navis. That was the great starry Ship that once sailed the southern skies.
By the way, don’t confuse Pyxis the Compass with Circinus. That’s a different constellation that represents a drawing compass.
Pyxis lies southeast of Canis Major the Greater Dog, with its very bright star Sirius. From Sirius, look toward the east to the quiet part of the sky where Pyxis resides. See the photo below.
The Alpha and Beta stars of Pyxis lie in the southern part of the constellation. More specifically, Alpha Pyxidis is magnitude 3.68 and lies 845 light-years away. Likewise, just over 2 degrees to the south is Beta Pyxidis at magnitude 3.97 and lying 388 light-years away.
In addition, both Alpha and Beta have faint star clusters lying a half degree to the northwest. Alpha’s star cluster is NGC 2658 at magnitude 9.2. And Beta’s star cluster is NGC 2635 at magnitude 11.2. So with this in mind, you’ll want binoculars or a telescope to track them down. In particular, NGC 2635 is a real challenge.
However, there are two other deep-sky targets in Pyxis that are somewhat brighter. First, there’s NGC 2627. It’s a magnitude 8.4 star cluster lying 3 1/2 degrees northwest of Alpha, or just 1/2 degree southwest of Zeta Pyxidis, a magnitude 4.86 star. Then, the second one lies in the southeast corner of the constellation. It’s NGC 2818, a planetary nebula shining at magnitude 11.6. Which we can see in the glorious Hubble photo, below.
The stars of Pyxis are difficult to see from a location with light pollution. For instance, Pyxis the Compass’s brightest star is a faint magnitude 3.68. Image via International Astronomical Union/ Wikimedia Commons (CC BY 3.0).The Hubble Space Telescope took this shot of the planetary nebula NGC 2818 in Pyxis in 2009. Image via NASA.
Bottom line: Pyxis the Compass is a constellation lying in southern skies. But Northern Hemisphere viewers can get a glimpse of in March. Nicolas-Louis de Lacaille created the constellation in the 1700s.
The March equinox will come on March 20, 2026, at 14:46 UTC (9:46 a.m. CDT). It’s the Northern Hemisphere’s autumn equinox and Southern Hemisphere’s spring equinox. You sometimes hear it said that, at the equinoxes, everyone receives equal daylight and darkness. But there’s really more daylight than darkness at the equinox, eight more minutes or so at mid-temperate latitudes. Two factors explain why we have more than 12 hours of daylight on this day of supposedly equal day and night. They are:
Illustrations like this one make it seem as if day and night should be equal at the equinox. In fact, they aren’t exactly equal. Image via Wikimedia Commons (CC BY-SA 2.0).
The sun is a disk, not a point
Watch any sunset, and you know the sun appears in Earth’s sky as a disk.
It’s not point-like, as stars are. And yet – by definition – most almanacs regard sunrise as when the leading edge of the sun first touches the eastern horizon. They define sunset as when the sun’s trailing edge finally touches the western horizon.
This provides an extra 2 1/2 to 3 minutes of daylight at mid-temperate latitudes.
Atmospheric refraction raises the sun about 1/2 degree upward in our sky at both sunrise and sunset. This advances the time of actual sunrise, while delaying the time of actual sunset. The result is several minutes of extra daylight, not just at an equinox, but every day. Image via Wikipedia (CC BY-SA 3.0).
Atmospheric refraction
The Earth’s atmosphere acts like a lens or prism. It uplifts the sun about 0.5 degrees from its true geometrical position whenever the sun nears the horizon. Coincidentally, the sun’s angular diameter spans about 0.5 degrees, as well.
In other words, when you see the sun on the horizon, it’s actually just below the horizon geometrically.
What does atmospheric refraction mean for the length of daylight? It advances the sunrise and delays the sunset, adding nearly another six minutes of daylight at mid-temperate latitudes. Hence, more daylight than night at the equinox.
Astronomical almanacs usually don’t give sunrise or sunset times to the second. That’s because atmospheric refraction varies somewhat, depending on air temperature, humidity and barometric pressure. Lower temperature, higher humidity and higher barometric pressure all increase atmospheric refraction.
On the day of the equinox, the center of the sun would set about 12 hours after rising. That’s given a level horizon, as at sea, and no atmospheric refraction.
So, no, day and night are not exactly equal at the equinox.
And here’s a new word for you, equilux. The word is used to describe the day on which day and night are equal. The equilux happens a few to several days after the autumn equinox, and a few to several days before the spring equinox.
Much as earliest sunrises and latest sunsets vary with latitude, so the exact date of an equilux varies with latitude. That’s in contrast to the equinox itself, which is a whole-Earth event, happening at the same instant worldwide. At and near the equator, there is no equilux whatsoever. That’s because the daylight period is over 12 hours long every day of the year.
Bottom line: There’s slightly more day than night on the day of an equinox. That’s because the sun is a disk, not a point of light, and because Earth’s atmosphere refracts (bends) sunlight.
The March equinox will come on March 20, 2026, at 14:46 UTC (9:46 a.m. CDT). It’s the Northern Hemisphere’s autumn equinox and Southern Hemisphere’s spring equinox. You sometimes hear it said that, at the equinoxes, everyone receives equal daylight and darkness. But there’s really more daylight than darkness at the equinox, eight more minutes or so at mid-temperate latitudes. Two factors explain why we have more than 12 hours of daylight on this day of supposedly equal day and night. They are:
Illustrations like this one make it seem as if day and night should be equal at the equinox. In fact, they aren’t exactly equal. Image via Wikimedia Commons (CC BY-SA 2.0).
The sun is a disk, not a point
Watch any sunset, and you know the sun appears in Earth’s sky as a disk.
It’s not point-like, as stars are. And yet – by definition – most almanacs regard sunrise as when the leading edge of the sun first touches the eastern horizon. They define sunset as when the sun’s trailing edge finally touches the western horizon.
This provides an extra 2 1/2 to 3 minutes of daylight at mid-temperate latitudes.
Atmospheric refraction raises the sun about 1/2 degree upward in our sky at both sunrise and sunset. This advances the time of actual sunrise, while delaying the time of actual sunset. The result is several minutes of extra daylight, not just at an equinox, but every day. Image via Wikipedia (CC BY-SA 3.0).
Atmospheric refraction
The Earth’s atmosphere acts like a lens or prism. It uplifts the sun about 0.5 degrees from its true geometrical position whenever the sun nears the horizon. Coincidentally, the sun’s angular diameter spans about 0.5 degrees, as well.
In other words, when you see the sun on the horizon, it’s actually just below the horizon geometrically.
What does atmospheric refraction mean for the length of daylight? It advances the sunrise and delays the sunset, adding nearly another six minutes of daylight at mid-temperate latitudes. Hence, more daylight than night at the equinox.
Astronomical almanacs usually don’t give sunrise or sunset times to the second. That’s because atmospheric refraction varies somewhat, depending on air temperature, humidity and barometric pressure. Lower temperature, higher humidity and higher barometric pressure all increase atmospheric refraction.
On the day of the equinox, the center of the sun would set about 12 hours after rising. That’s given a level horizon, as at sea, and no atmospheric refraction.
So, no, day and night are not exactly equal at the equinox.
And here’s a new word for you, equilux. The word is used to describe the day on which day and night are equal. The equilux happens a few to several days after the autumn equinox, and a few to several days before the spring equinox.
Much as earliest sunrises and latest sunsets vary with latitude, so the exact date of an equilux varies with latitude. That’s in contrast to the equinox itself, which is a whole-Earth event, happening at the same instant worldwide. At and near the equator, there is no equilux whatsoever. That’s because the daylight period is over 12 hours long every day of the year.
Bottom line: There’s slightly more day than night on the day of an equinox. That’s because the sun is a disk, not a point of light, and because Earth’s atmosphere refracts (bends) sunlight.
A comet breaks apart in this series of images from NASA’s Hubble Space Telescope. The comet was C/2025 K1 (ATLAS) (not to be confused with the interstellar comet 3I/ATLAS). These images document 3 consecutive days: November 8, 9 and 10, 2025. It’s the first time Hubble witnessed a comet so early in the process of breaking up. Image via NASA/ ESA/ Dennis Bodewits (AU). Image Processing: Joseph DePasquale (STScI).
Hubble has captured a rare view of a comet breaking apart. It captured these images about a month after the comet made its closest pass by the sun.
The discovery was a happy accident. The scientist’s original target was a different comet. But this is the first time Hubble has caught a fragmenting comet so close to when it actually fell apart.
The breakup offers scientists a glimpse of pristine material, helping them study the early solar system’s building blocks.
In a happy twist of fate, NASA’s Hubble Space Telescope just witnessed a comet in the act of breaking apart. The chance of that happening while Hubble watched is extraordinarily minuscule. The comet K1, whose full name is C/2025 K1 (ATLAS) – not to be confused with interstellar comet 3I/ATLAS – was not the original target of the Hubble study.
Co-investigator John Noonan, a research professor in the Department of Physics at Auburn University in Alabama, said:
Sometimes the best science happens by accident. This comet got observed because our original comet was not viewable due to some new technical constraints after we won our proposal. We had to find a new target … and right when we observed it, it happened to break apart, which is the slimmest of slim chances.
Noonan didn’t know K1 was fragmenting until he viewed the images the day after Hubble took them. Noonan said:
While I was taking an initial look at the data, I saw that there were four comets in those images when we only proposed to look at one. So we knew this was something really, really special.
This is an experiment the researchers always wanted to do with Hubble. They had proposed many Hubble observations to catch a comet breaking up. Unfortunately, these are very difficult to schedule, and they were never successful. Principal investigator Dennis Bodewits, also a professor in Auburn University’s Department of Physics, said:
The irony is now we’re just studying a regular comet and it crumbles in front of our eyes.
Comets are leftovers of the era of solar system formation, so they’re made of ‘old stuff’: the primordial materials that made our solar system. But they are not pristine. They’ve been heated; they’ve been irradiated by the sun and by cosmic rays. So, when looking at a comet’s composition, the question we always have is, ‘Is this a primitive property or is this due to evolution?’ By cracking open a comet, you can see the ancient material that has not been processed.
This diagram shows the path Comet C/2025 K1 (ATLAS), or K1, took as it swung past the sun and began its journey out of the solar system. NASA’s Hubble Space Telescope captured the inset image of the fragmenting comet just a month after K1’s closest approach to the sun. Illustration via NASA/ ESA/ Ralf Crawford (STScI).
A closer look at a solar system breakup
Hubble caught K1 fragmenting into at least four pieces. Each had a distinct coma, which is the fuzzy envelope of gas and dust that surrounds a comet’s icy nucleus. Hubble cleanly resolved the fragments. But to ground-based telescopes at the time, they only appeared as barely distinguishable, bright blobs.
Hubble took its images just a month after K1’s closest approach to the sun, called perihelion. The comet’s perihelion was inside Mercury’s orbit, about one-third the distance of the Earth from the sun. During perihelion, a comet experiences its most intense heating and maximum stress. Just past perihelion is when some long-period comets like K1 tend to fall apart.
Before it fragmented, K1 was likely a bit larger than an average comet, probably around 5 miles (8 km) across. The team estimates the comet began to disintegrate eight days before Hubble viewed it. Hubble took three 20-second images, one on each day from November 8 through 10, 2025. As it watched the comet, one of K1’s smaller pieces also broke up.
Because Hubble’s sharp vision can distinguish extremely fine details, the team could trace the history of the fragments back to when they were one piece. That allowed them to reconstruct the timeline. But in doing so, they uncovered a mystery: Why was there a delay between when the comet broke up and when bright outbursts were seen from the ground? When the comet fragmented and exposed fresh ice, why didn’t it brighten almost instantaneously?
Exploring the mysteries of comet K1 ATLAS
The team has some theories. Most of a comet’s brightness is sunlight reflected off of dust grains. But when a comet cracks open, it reveals pure ice. Maybe a layer of dry dust needs to form over the pure ice and then blow off. Or maybe heat needs to get below the surface, build up pressure, and then eject an expanding shell of dust. Noonan said:
Never before has Hubble caught a fragmenting comet this close to when it actually fell apart. Most of the time, it’s a few weeks to a month later. And in this case, we were able to see it just days after. This is telling us something very important about the physics of what’s happening at the comet’s surface. We may be seeing the timescale it takes to form a substantial dust layer that can then be ejected by the gas.
The research team is looking forward to finishing the analysis of the gases to come from the comet. Already, ground-based analysis shows that K1 is chemically very strange. It is significantly depleted in carbon compared with other comets. Spectroscopic analysis from Hubble’s STIS (Space Telescope Imaging Spectrograph) and COS (Cosmic Origins Spectrograph) instruments is likely to reveal much more about the composition of K1 and the very origins of our solar system.
The comet K1 is now a collection of fragments about 250 million miles from Earth. Located in the constellation Pisces, it is heading out of the solar system, not likely to ever return.
Bottom line: Hubble captures a rare moment as a comet breaks apart after passing close to our sun. The images revealing ancient material from the early solar system.
A comet breaks apart in this series of images from NASA’s Hubble Space Telescope. The comet was C/2025 K1 (ATLAS) (not to be confused with the interstellar comet 3I/ATLAS). These images document 3 consecutive days: November 8, 9 and 10, 2025. It’s the first time Hubble witnessed a comet so early in the process of breaking up. Image via NASA/ ESA/ Dennis Bodewits (AU). Image Processing: Joseph DePasquale (STScI).
Hubble has captured a rare view of a comet breaking apart. It captured these images about a month after the comet made its closest pass by the sun.
The discovery was a happy accident. The scientist’s original target was a different comet. But this is the first time Hubble has caught a fragmenting comet so close to when it actually fell apart.
The breakup offers scientists a glimpse of pristine material, helping them study the early solar system’s building blocks.
In a happy twist of fate, NASA’s Hubble Space Telescope just witnessed a comet in the act of breaking apart. The chance of that happening while Hubble watched is extraordinarily minuscule. The comet K1, whose full name is C/2025 K1 (ATLAS) – not to be confused with interstellar comet 3I/ATLAS – was not the original target of the Hubble study.
Co-investigator John Noonan, a research professor in the Department of Physics at Auburn University in Alabama, said:
Sometimes the best science happens by accident. This comet got observed because our original comet was not viewable due to some new technical constraints after we won our proposal. We had to find a new target … and right when we observed it, it happened to break apart, which is the slimmest of slim chances.
Noonan didn’t know K1 was fragmenting until he viewed the images the day after Hubble took them. Noonan said:
While I was taking an initial look at the data, I saw that there were four comets in those images when we only proposed to look at one. So we knew this was something really, really special.
This is an experiment the researchers always wanted to do with Hubble. They had proposed many Hubble observations to catch a comet breaking up. Unfortunately, these are very difficult to schedule, and they were never successful. Principal investigator Dennis Bodewits, also a professor in Auburn University’s Department of Physics, said:
The irony is now we’re just studying a regular comet and it crumbles in front of our eyes.
Comets are leftovers of the era of solar system formation, so they’re made of ‘old stuff’: the primordial materials that made our solar system. But they are not pristine. They’ve been heated; they’ve been irradiated by the sun and by cosmic rays. So, when looking at a comet’s composition, the question we always have is, ‘Is this a primitive property or is this due to evolution?’ By cracking open a comet, you can see the ancient material that has not been processed.
This diagram shows the path Comet C/2025 K1 (ATLAS), or K1, took as it swung past the sun and began its journey out of the solar system. NASA’s Hubble Space Telescope captured the inset image of the fragmenting comet just a month after K1’s closest approach to the sun. Illustration via NASA/ ESA/ Ralf Crawford (STScI).
A closer look at a solar system breakup
Hubble caught K1 fragmenting into at least four pieces. Each had a distinct coma, which is the fuzzy envelope of gas and dust that surrounds a comet’s icy nucleus. Hubble cleanly resolved the fragments. But to ground-based telescopes at the time, they only appeared as barely distinguishable, bright blobs.
Hubble took its images just a month after K1’s closest approach to the sun, called perihelion. The comet’s perihelion was inside Mercury’s orbit, about one-third the distance of the Earth from the sun. During perihelion, a comet experiences its most intense heating and maximum stress. Just past perihelion is when some long-period comets like K1 tend to fall apart.
Before it fragmented, K1 was likely a bit larger than an average comet, probably around 5 miles (8 km) across. The team estimates the comet began to disintegrate eight days before Hubble viewed it. Hubble took three 20-second images, one on each day from November 8 through 10, 2025. As it watched the comet, one of K1’s smaller pieces also broke up.
Because Hubble’s sharp vision can distinguish extremely fine details, the team could trace the history of the fragments back to when they were one piece. That allowed them to reconstruct the timeline. But in doing so, they uncovered a mystery: Why was there a delay between when the comet broke up and when bright outbursts were seen from the ground? When the comet fragmented and exposed fresh ice, why didn’t it brighten almost instantaneously?
Exploring the mysteries of comet K1 ATLAS
The team has some theories. Most of a comet’s brightness is sunlight reflected off of dust grains. But when a comet cracks open, it reveals pure ice. Maybe a layer of dry dust needs to form over the pure ice and then blow off. Or maybe heat needs to get below the surface, build up pressure, and then eject an expanding shell of dust. Noonan said:
Never before has Hubble caught a fragmenting comet this close to when it actually fell apart. Most of the time, it’s a few weeks to a month later. And in this case, we were able to see it just days after. This is telling us something very important about the physics of what’s happening at the comet’s surface. We may be seeing the timescale it takes to form a substantial dust layer that can then be ejected by the gas.
The research team is looking forward to finishing the analysis of the gases to come from the comet. Already, ground-based analysis shows that K1 is chemically very strange. It is significantly depleted in carbon compared with other comets. Spectroscopic analysis from Hubble’s STIS (Space Telescope Imaging Spectrograph) and COS (Cosmic Origins Spectrograph) instruments is likely to reveal much more about the composition of K1 and the very origins of our solar system.
The comet K1 is now a collection of fragments about 250 million miles from Earth. Located in the constellation Pisces, it is heading out of the solar system, not likely to ever return.
Bottom line: Hubble captures a rare moment as a comet breaks apart after passing close to our sun. The images revealing ancient material from the early solar system.
This map shows the forecast high temperatures for Wednesday, March 18, through Sunday, March 22, 2026. If these high temperatures materialize, they will break the record highs for these locations. Read more about the early season heatwave hitting this week. Image via NWS.
Early season heatwave in US to bring possible record temps
An early spring heatwave is set to bring record temperatures for this time of year to much of the U.S. this week.
Thanks to a strong ridge of high pressure centered over the American Southwest, temperatures in the region could hit 100 degrees F (38 C) at the earliest time of year since 1988. Across California and the desert southwest, temperatures are forecast to be 20 to 30 degrees Fahrenheit (11 to 17°C) warmer than normal for this time of year. The heatwave will then expand east, toward the Rockies and Great Plains.
This heatwave is going to be persistent. The heat dome is already building. Some areas can expect record-high temps all the way through Sunday. The triple-digit heat may ease by early next week. However, forecasts call for temperatures to stay above average for the next week and a half. And that’s not just in the southwestern United States but across most of the country.
The Climate Prediction Center has outlined a majority of the United States for a higher probability of warmer-than-average temperatures through March 27, 2026. This doesn’t mean most of the country will break high temperature records or soar into the triple digits. But it does mean temperatures have a better chance of being warmer than normal for that region during this time frame.
The 6-10 day temperature outlook from the Climate Prediction Center. Image via CPC.
Heat advisories
Normally associated with summer, heat advisories are issued by local weather service offices whenever they expect the heat to be a danger to health and safety.
In the southwestern United States, an Extreme Heat Warning is already out for parts of Southern California into southern Arizona. This means meteorologists expect extremely dangerous heat or it’s already occurring. During an Extreme Heat Warning, you shouldn’t go outside during the hottest part of the day unless absolutely necessary. If you cannot avoid being outside, stay well-hydrated with water, take frequent breaks in the shade, but find air-conditioning as often as possible.
An Extreme Heat Warning is in effect for the southwestern United States. Image via NWS Phoenix.
When hot weather is on the way, you may get an Extreme Heat Watch. This means the extreme, dangerous heat is possible but hasn’t arrived just yet. The NWS issues these watches so you can prepare for dangerous heat. Steps to take include having a backup for outdoor plans, finding the closest cooling center and checking in on family and friends.
Arizona in the bull’s-eye
For Phoenix, Arizona, the National Weather Service is forecasting a high temperature for Wednesday, March 18, 2026, of 102 F (39 C). This would not only break the high temperature record for the day, but it would be the earliest 100-degree day by nearly 40 years.
The earliest Phoenix has ever hit the 100-degree mark was March 26, 1988. And it’s almost two months ahead of when Phoenix typically experiences its first triple-digit temp. The average first 100-degree day is May 2. That’s based on the 30-year climate data for that area. The dangerous heat will persist in the Southwest through the weekend.
Forecasters call for high temperatures climbing to as hot as 106 F (41 C) on Friday and Saturday.
Expect a stretch of record high temperatures in Arizona through the end of the week. Image via NWS Phoenix.According to the National Weather Service in Phoenix, the city could break its all-time high temperatures for both March and April this week. The previous earliest-ever heat warning was issued April 26–30, 2020, and Phoenix now faces an extreme heat warning. Image via NWS.
Staying safe in extreme heat
Staying safe in extreme heat can vary a bit depending on your situation. But the main idea is to avoid the heat as much as possible. If you are able to stay inside, ideally in air-conditioning, this is your best option. But as mentioned, if you cannot avoid the hot weather, there are things you can do. Take frequent breaks in the shade. Make sure you’re staying hydrated. Wear light color, loose-fitting clothing. And pay close attention to how you’re feeling as the day goes on.
If you, or someone you are with, is sweating heavily, feeling weak, tired, dizzy or nauseated, these could be signs of heat exhaustion. Immediately move yourself or the other person into A/C. Loosen their clothing, give them sips of cool water and put cold compresses on their body.
If someone is acting confused and slurring their speech, has red and hot skin or passes out, this is likely a heat stroke. They need medical attention immediately! Call 911. While you wait for help to arrive, move the person to A/C, add cool compresses to lower their body temperature, but do not give them anything to drink.
The heat can also be more dangerous to the very young, the very old, people with chronic medical conditions and pregnant women. In addition, the unhoused and lower income communities, who may not be able to afford to run their air-conditioning, are also at risk. Check on your friends, family and neighbors before, during and after extreme heat.
Early season heat is expected in the southwest, possibly the first 100°F of the year. Image via Pexels.
Bottom line: Forecasters are calling for an early season heatwave in the southwestern United States, spreading east. Get details here. Plus how to prepare before the heat hits.
This map shows the forecast high temperatures for Wednesday, March 18, through Sunday, March 22, 2026. If these high temperatures materialize, they will break the record highs for these locations. Read more about the early season heatwave hitting this week. Image via NWS.
Early season heatwave in US to bring possible record temps
An early spring heatwave is set to bring record temperatures for this time of year to much of the U.S. this week.
Thanks to a strong ridge of high pressure centered over the American Southwest, temperatures in the region could hit 100 degrees F (38 C) at the earliest time of year since 1988. Across California and the desert southwest, temperatures are forecast to be 20 to 30 degrees Fahrenheit (11 to 17°C) warmer than normal for this time of year. The heatwave will then expand east, toward the Rockies and Great Plains.
This heatwave is going to be persistent. The heat dome is already building. Some areas can expect record-high temps all the way through Sunday. The triple-digit heat may ease by early next week. However, forecasts call for temperatures to stay above average for the next week and a half. And that’s not just in the southwestern United States but across most of the country.
The Climate Prediction Center has outlined a majority of the United States for a higher probability of warmer-than-average temperatures through March 27, 2026. This doesn’t mean most of the country will break high temperature records or soar into the triple digits. But it does mean temperatures have a better chance of being warmer than normal for that region during this time frame.
The 6-10 day temperature outlook from the Climate Prediction Center. Image via CPC.
Heat advisories
Normally associated with summer, heat advisories are issued by local weather service offices whenever they expect the heat to be a danger to health and safety.
In the southwestern United States, an Extreme Heat Warning is already out for parts of Southern California into southern Arizona. This means meteorologists expect extremely dangerous heat or it’s already occurring. During an Extreme Heat Warning, you shouldn’t go outside during the hottest part of the day unless absolutely necessary. If you cannot avoid being outside, stay well-hydrated with water, take frequent breaks in the shade, but find air-conditioning as often as possible.
An Extreme Heat Warning is in effect for the southwestern United States. Image via NWS Phoenix.
When hot weather is on the way, you may get an Extreme Heat Watch. This means the extreme, dangerous heat is possible but hasn’t arrived just yet. The NWS issues these watches so you can prepare for dangerous heat. Steps to take include having a backup for outdoor plans, finding the closest cooling center and checking in on family and friends.
Arizona in the bull’s-eye
For Phoenix, Arizona, the National Weather Service is forecasting a high temperature for Wednesday, March 18, 2026, of 102 F (39 C). This would not only break the high temperature record for the day, but it would be the earliest 100-degree day by nearly 40 years.
The earliest Phoenix has ever hit the 100-degree mark was March 26, 1988. And it’s almost two months ahead of when Phoenix typically experiences its first triple-digit temp. The average first 100-degree day is May 2. That’s based on the 30-year climate data for that area. The dangerous heat will persist in the Southwest through the weekend.
Forecasters call for high temperatures climbing to as hot as 106 F (41 C) on Friday and Saturday.
Expect a stretch of record high temperatures in Arizona through the end of the week. Image via NWS Phoenix.According to the National Weather Service in Phoenix, the city could break its all-time high temperatures for both March and April this week. The previous earliest-ever heat warning was issued April 26–30, 2020, and Phoenix now faces an extreme heat warning. Image via NWS.
Staying safe in extreme heat
Staying safe in extreme heat can vary a bit depending on your situation. But the main idea is to avoid the heat as much as possible. If you are able to stay inside, ideally in air-conditioning, this is your best option. But as mentioned, if you cannot avoid the hot weather, there are things you can do. Take frequent breaks in the shade. Make sure you’re staying hydrated. Wear light color, loose-fitting clothing. And pay close attention to how you’re feeling as the day goes on.
If you, or someone you are with, is sweating heavily, feeling weak, tired, dizzy or nauseated, these could be signs of heat exhaustion. Immediately move yourself or the other person into A/C. Loosen their clothing, give them sips of cool water and put cold compresses on their body.
If someone is acting confused and slurring their speech, has red and hot skin or passes out, this is likely a heat stroke. They need medical attention immediately! Call 911. While you wait for help to arrive, move the person to A/C, add cool compresses to lower their body temperature, but do not give them anything to drink.
The heat can also be more dangerous to the very young, the very old, people with chronic medical conditions and pregnant women. In addition, the unhoused and lower income communities, who may not be able to afford to run their air-conditioning, are also at risk. Check on your friends, family and neighbors before, during and after extreme heat.
Early season heat is expected in the southwest, possibly the first 100°F of the year. Image via Pexels.
Bottom line: Forecasters are calling for an early season heatwave in the southwestern United States, spreading east. Get details here. Plus how to prepare before the heat hits.
View at EarthSky Community Photos. |Rupesh Sangoi in Mumbai, India, captured separate images of the sunrise, showing the sun’s movement along the horizon, between the June and December solstices and on the equinoxes. Rupesh wrote: “Did this for over a year, at sunrise.” Glorious composite, Rupesh! Thank you.
The sun’s movement from day to day along your horizon – at the sunrise or sunset point – is most noticeable around the equinoxes. And many streets in the U.S. and in other parts of the world are oriented either north-south or east-west. So, just by looking out the doorway of your home, you might be able to watch the progress of the sun as it slides from south to north in the weeks and months following the March equinox.
On the equinox, the sun rises directly in the east and sets directly in the west. You can see it move quickly further north each day afterward. No grid of streets to help you? Try tracking the sun’s progress along the horizon by placing bits of tape on an east- or west-facing window of your home. Or just find a clear spot – a place where you can see the horizon – and stand in the same spot whenever you watch the sunrise or sunset. You’ll notice the sun’s movement with respect to trees and other objects in the foreground.
Just be sure to observe from the exact same location every day. It’s enough to note the sunrise or sunset point every week or 10 days. You’ll easily see the sun’s northward shift between now and the June solstice.
Then track between the solstices
What happens at the solstice? At mid-northern latitudes, there’s a two- to three-week time period where you probably won’t discern any movement of the sun along the horizon. That’s where the word solstice comes from. Solstice = sun still.
As mentioned above, the sun’s movement along your horizon – at sunrise or sunset – is most perceptible around the equinoxes and least perceptible around the solstices. Also, the sun’s daily change of position along the horizon is greater the farther north or south you are from Earth’s equator.
It’s all about your latitude
For example, at around 40 degrees north latitude (Denver, Colorado; island of Sardinia, Italy; Beijing, China), the sun pretty much rises due east and sets due west on the day of the March 20 equinox. Two weeks later, on April 4, the sun rises about 7 degrees north of due east and sets about 7 degrees north of due west. Because the sun’s diameter equals 1/2 degree, that means the sun has been traveling its own diameter (14 days x 1/2 degree = 7 degrees) northward daily.
At 65 degrees north latitude (Fairbanks, Alaska; Siberia; Iceland), the sun also rises and sets close to due east and due west on the day of the equinox. But two weeks later, on April 4, the sun rises and sets about 14 degrees north of due east and west. So, at this far-northern latitude, the sun moves about one degree (two sun-diameters) along the horizon daily during this two-week period from the spring equinox to April 4.
You can track the position of the sunset (or sunrise) location along the horizon during the different seasons. Image via EarthSky.org.
Bottom line: The amount of the sun’s movement along your horizon – at sunrise or sunset – varies with the time of year and with your latitude. It’s most perceptible around the equinoxes and least around the solstices.
View at EarthSky Community Photos. |Rupesh Sangoi in Mumbai, India, captured separate images of the sunrise, showing the sun’s movement along the horizon, between the June and December solstices and on the equinoxes. Rupesh wrote: “Did this for over a year, at sunrise.” Glorious composite, Rupesh! Thank you.
The sun’s movement from day to day along your horizon – at the sunrise or sunset point – is most noticeable around the equinoxes. And many streets in the U.S. and in other parts of the world are oriented either north-south or east-west. So, just by looking out the doorway of your home, you might be able to watch the progress of the sun as it slides from south to north in the weeks and months following the March equinox.
On the equinox, the sun rises directly in the east and sets directly in the west. You can see it move quickly further north each day afterward. No grid of streets to help you? Try tracking the sun’s progress along the horizon by placing bits of tape on an east- or west-facing window of your home. Or just find a clear spot – a place where you can see the horizon – and stand in the same spot whenever you watch the sunrise or sunset. You’ll notice the sun’s movement with respect to trees and other objects in the foreground.
Just be sure to observe from the exact same location every day. It’s enough to note the sunrise or sunset point every week or 10 days. You’ll easily see the sun’s northward shift between now and the June solstice.
Then track between the solstices
What happens at the solstice? At mid-northern latitudes, there’s a two- to three-week time period where you probably won’t discern any movement of the sun along the horizon. That’s where the word solstice comes from. Solstice = sun still.
As mentioned above, the sun’s movement along your horizon – at sunrise or sunset – is most perceptible around the equinoxes and least perceptible around the solstices. Also, the sun’s daily change of position along the horizon is greater the farther north or south you are from Earth’s equator.
It’s all about your latitude
For example, at around 40 degrees north latitude (Denver, Colorado; island of Sardinia, Italy; Beijing, China), the sun pretty much rises due east and sets due west on the day of the March 20 equinox. Two weeks later, on April 4, the sun rises about 7 degrees north of due east and sets about 7 degrees north of due west. Because the sun’s diameter equals 1/2 degree, that means the sun has been traveling its own diameter (14 days x 1/2 degree = 7 degrees) northward daily.
At 65 degrees north latitude (Fairbanks, Alaska; Siberia; Iceland), the sun also rises and sets close to due east and due west on the day of the equinox. But two weeks later, on April 4, the sun rises and sets about 14 degrees north of due east and west. So, at this far-northern latitude, the sun moves about one degree (two sun-diameters) along the horizon daily during this two-week period from the spring equinox to April 4.
You can track the position of the sunset (or sunrise) location along the horizon during the different seasons. Image via EarthSky.org.
Bottom line: The amount of the sun’s movement along your horizon – at sunrise or sunset – varies with the time of year and with your latitude. It’s most perceptible around the equinoxes and least around the solstices.
A galaxy is a vast island of gas, dust and stars in an ocean of space. Typically, galaxies are millions of light-years apart. Galaxies are the building blocks of our universe. Their distribution isn’t random, as one might suppose. Instead, galaxies reside along unimaginably long filaments across the universe, forming a cosmic web of star cities.
View larger. | Have you ever wondered what a galaxy is or how many galaxies are in the universe? Here’s the Webb telescope’s 1st deep field, released in July 2022. This near-infrared image of the galaxy cluster SMACS 0723 contains thousands of galaxies. High-resolution imaging from Webb – combined with a natural effect known as gravitational lensing – made this finely detailed image possible. Image via NASA/ ESA/ CSA/ STScI. Read more about this image.
A galaxy can contain hundreds of billions of stars and be many thousands of light-years across. Our own galaxy, the Milky Way, is around 100,000 light-years in diameter. That’s about 587,900 trillion miles, or nearly a million trillion kilometers.
The three types of galaxies are spiral, elliptical or irregular.
Galaxy sizes vary widely, ranging from very small to unbelievably enormous. Small dwarf galaxies contain about 100 million stars. Giant galaxies contain more than a trillion stars.
Also, there are an estimated two hundred billion galaxies in the universe.
Here is a closeup view of 1 small portion of a Webb image that shows more than 45,000 galaxies. Image via NASA/ ESA/ CSA/ Brant Robertson (UC Santa Cruz)/ Ben Johnson (CfA)/ Sandro Tacchella (Cambridge)/ Marcia Rieke (University of Arizona)/ Daniel Eisenstein (CfA)/ Alyssa Pagan (STScI).
The discovery of other galaxies
The famous astronomer Edwin P. Hubble first classified galaxies based on their visual appearance in the late 1920s and 30s. In fact, Hubble’s classification of galaxies remains in use today. Of course, since Hubble’s time, like any effective classification system, it has evolved from ongoing observations. Hubble identified several basic types of galaxies, each containing subtypes.
— Royal Astronomical Society (@RoyalAstroSoc) June 11, 2019
Before Hubble’s study of galaxies, we believed that our galaxy was the only one in the universe. Astronomers thought that the smudges of light they saw through their telescopes were in fact nebulae within our own galaxy. However, Hubble discovered that these nebulae were galaxies. Additionally, it was Hubble who demonstrated, by measuring their velocities, that they lie at vast distances from us.
Galaxies are light-years away
These galaxies lie millions of light-years beyond the Milky Way. The distances are so huge these galaxies appear tiny in all but the largest telescopes. Moreover, Hubble demonstrated that, wherever he looked, galaxies were receding from us in all directions. And the farther away they are, the faster they are receding. Thus, Hubble had discovered that the universe is expanding.
View at EarthSky Community Photos. | Harshwardhan Pathak of India, using a large remote telescope in Chile, captured the galaxy NGC 1232 in the constellation Eridanus on February 1, 2024. Harshwardhan wrote: “NGC 1232, also known as the Eye of God Galaxy, is an intermediate spiral galaxy about 60 million light-years away. German-British astronomer William Herschel discovered it on October 20, 1784.” Thank you, Harshwardhan!
Spiral galaxies
The most common type of galaxy is a spiral galaxy. The Milky Way is a spiral galaxy. Spiral galaxies have majestic, sweeping arms, thousands of light-years long. They contain millions upon millions of stars. Their spiral arms stand out because of bright stars, glowing gas and dust. Spiral galaxies are active with star formation.
Also, spiral galaxies have a bright center, made up of a dense concentration of stars. There are so many stars that from a distance the galaxy’s center looks like a solid ball. This ball of stars is known as the galactic bulge.
Also, there are two types of spiral galaxies. There are regular spirals and barred spirals. If the spiral has bars, they extend off the central bulge. Then, the spiral arms start at the end of the bar. In fact, the Milky Way Galaxy is a barred spiral galaxy.
The 3 most common types of galaxies. The top row shows schematic illustrations, and the bottom row shows actual images of galaxies that fit each of the 3 categories. Image via A. Feild/ STScI/ Hubblesite.
Elliptical and irregular galaxies
Elliptical galaxies are the universe’s largest galaxies. In fact, giant elliptical galaxies can be about 300,000 light-years across. But dwarf elliptical galaxies – the most common elliptical – are only a few thousand light-years across. There are several shapes of elliptical galaxies, ranging from circular to football-shaped.
Overall, 1/3 of all galaxies are elliptical galaxies. Elliptical galaxies contain very little gas and dust compared to a spiral or irregular galaxy. They are no longer actively forming stars. The stars in elliptical galaxies are older stars and contain very few heavier elements.
Irregular-shaped galaxies have all sorts of different shapes but they don’t look like a spiral or elliptical galaxy.
Irregular galaxies can have very little dust or a lot. Plus, they can show active star-forming regions or have little-to-no star formation occurring. They seemed plentiful in the early universe.
View larger. | This Hubble Space Telescope mosaic is of a portion of the immense Coma Berenices galaxy cluster. Be sure to use the view larger link and zoom in to see how much larger the football-shaped elliptical galaxies are, in contrast to the spiral galaxies. Image via NASA/ ESA/ J. Mack (STScI)/ J. Madrid (Australian Telescope National Facility).
Our Milky Way Galaxy
The Milky Way, in fact, falls into one of Hubble’s spiral galaxy sub-types. It’s a barred spiral, which means it has a bar of stars protruding out from each side of its center. As the spiral arms sweep out in their graceful and enormous arcs, the ends of the bars are the anchors. This is a recent discovery and it’s unknown how bars form in a galaxy. Our solar system is situated about 2/3 of the way out from the galactic center toward the periphery of the galaxy, embedded in one of these spiral arms.
Another recent discovery is that the disk of the Milky Way is warped, like a long-playing vinyl record left too long in the sun. Exactly why is unknown, but it may be the result of a gravitational encounter with another galaxy early in the Milky Way’s history.
It also appears that all galaxies rotate. For example, the Milky Way takes 226 million years to spin around once. Since its creation, the Earth has traveled 20 times around the galaxy.
Galaxies come in clusters
Galaxies group together in clusters. Our own galaxy is part of what is called the Local Group, and it contains at least 80 galaxies. The three large galaxies in the Local Group are the Andromeda Galaxy, the Milky Way Galaxy and the Triangulum Galaxy. The rest of the galaxies in our local group are dwarf galaxies.
The “glue” that binds stars into galaxies, galaxies into clusters, clusters into superclusters and superclusters into filaments is – of course – gravity. In fact, gravity is the universe’s construction worker, which sculpts all the structures we see in the cosmos.
The Universe is Infinite. However our existence in our current Galaxy Cluster is Finite. Time is also a factor… Our Galaxy Clusters actually expand into the void of space over time. pic.twitter.com/EAOcisPdZn
Most galaxies are flying apart from each other. But those astronomically close to each other will be gravitationally bound to each other. Caught in an inexorable gravitational dance, eventually they merge, passing through each other over millions of years. They eventually form a single, amorphous elliptical galaxy. Gravity shockwaves compress huge clouds of interstellar gas and dust during such mergers, giving rise to new generations of stars.
The Milky Way is caught in such a gravitational embrace with M31, aka the Andromeda Galaxy, which is 2 1/2 million light-years distant. Both galaxies are moving toward each other because of gravitational attraction: they will merge in about 6 billion years. However, huge halos of gas surround both galaxies and may extend for millions of light-years. And it was discovered that the halos of the Milky Way and M31 have already started to touch.
Galaxy mergers and companion galaxies
Galaxy mergers are common. The universe is full of examples of galaxies in various stages of merging together, their structures disrupted and distorted by gravity, forming bizarre and beautiful shapes.
Galaxies may take billions of years to fully merge into a single galaxy. As astronomers look outward in space, they can only see glimpses of this long merger process. Located 300 million light-years away in the constellation Coma Berenices, these 2 colliding galaxies have been nicknamed the Mice Galaxies because of the long tails of stars and gas emanating from each galaxy. Otherwise known as NGC 4676, the pair will eventually merge into a single giant galaxy. Image via NASA/ ESA/ Wikimedia Commons (public domain).
Then, at the lower end of the galactic size scale, there are so-called dwarf galaxies. They consist of a few hundred to up to several billion stars. Their origin is not clear. Typically, they have no clearly defined structure. Astronomers believe they were born in the same way as larger galaxies like the Milky Way, but for whatever reason they stopped growing. Ensnared by the gravity of a larger galaxy, they orbit its periphery. The Milky Way has around 60 dwarf galaxies orbiting it that we know of, although some models predict there should be many more.
The two most famous dwarf galaxies for us earthlings are, of course, the Large and Small Magellanic Clouds, visible to the unaided eye in Earth’s Southern Hemisphere sky.
Eventually, these and other dwarf galaxies will rip apart under the titanic pull of the Milky Way’s gravity. This will leave behind a barely noticeable stream of stars across the sky, slowly dissipating over eons.
The Large Magellanic Cloud spills across the border of Dorado and Mensa. The Small Magellanic Cloud is at lower left. Image via Yuri Beletsky/ LCO/ ESO.
Supermassive black holes lurk in galaxy centers
At the center of most galaxies lurks a supermassive black hole, of millions or even billions of solar masses. For example, TON 618, has a mass 66 billion times that of our sun. The one at the center of our own Milky Way galaxy possesses 4.6 million solar masses.
The origin and evolution of supermassive black holes remains a mystery. A few years ago, astronomers uncovered a surprising fact: in spiral galaxies, the mass of the supermassive black hole has a direct linear relationship with the mass of the galactic bulge. The more mass the black hole has, the more stars there are in the bulge. No one knows exactly what the significance of this relationship may be. However, its existence seems to indicate that the growth of a galaxy’s stellar population is linked to that of its supermassive black hole.
This discovery comes at a time when astronomers are beginning to realize that a supermassive black hole may control the fate of its host galaxy. The copious amount of electromagnetic radiation emitted from the maelstrom of material orbiting the central black hole. This is known as the accretion disk, and the radiation may push away and dissipate the clouds of interstellar hydrogen from which new stars form. This acts as an inhibitor on the galaxy’s ability to give birth to new stars. Ultimately, the activity of supermassive black holes may link to the emergence of life itself. This is an area that is undergoing extensive research.
While astronomers still know very little about exactly how galaxies formed in the first place – we see them in their nascent state only a few hundred million years after the Big Bang – the study of galaxies is an endless voyage of discovery.
We discovered other galaxies exist about a century ago
Around a hundred years ago we realized that other galaxies exist besides our own. Since then, we have learned so much about these grand, majestic star cities. And there is still much to learn.
Some galaxies from our EarthSky Community Photos
View at EarthSky Community Photos. | Shaurya Salunkhe in Velhe, Maharashtra, India, used a telephoto lens to capture this view of Messier 31, the Andromeda Galaxy, on January 11, 2026. Shaurya wrote: “I captured the Andromeda Galaxy, the Milky Way’s closest neighbor and the largest galaxy of the Local Group. This is the farthest object that is visible to the unaided eye. It’s 3 times larger than the Milky Way and is approximately 2.5 million light-years away. It is a fascinating target with stunning colours not to mention the bonus little galaxies (M32 and M110) near it.” Thank you, Shaurya!View at EarthSky Community Photos. | Andy Dungan near Cotopaxi, Colorado, captured this view of spiral galaxy IC 342, in the constellation Camelopardalis (also known as Caldwell 5), on June 22, 2025. Andy wrote: “This is really sort of the first of the winter galaxies. The challenge for taking pics of this galaxy is how dim it is compare to many others of its size. Evidently there is a substantial amount of dust someplace in between here and the 7-10 million light-years to the galaxy. As I said above more exposure and using PixInsight made a substantial difference in the quality of the pic. Ya, progress!!” Thank you, Andy!View at EarthSky Community Photos. | EarthSky’s own Marcy Curran in Cheyenne, Wyoming, captured the Pinwheel Galaxy on July 1, 2025. Marcy wrote: “The Pinwheel Galaxy (M101) is a face-on, counterclockwise intermediate spiral galaxy. It’s 21 million light-years from Earth in the constellation Ursa Major. It has a diameter of approximately 252,000 light-years and contains around one trillion stars. Pierre Méchain discovered it in 1781. Then Charles Messier verified its position before adding it to his Messier Catalog. It was 101 out of 110 deep-sky objects. The beautiful Pinwheel Galaxy is a near-perfect representation of a spiral galaxy.” Thank you, Marcy!
Bottom line: A galaxy is a vast island of gas, dust and stars in an ocean of space. There are three types of galaxies. Learn about these starry islands in space.
A galaxy is a vast island of gas, dust and stars in an ocean of space. Typically, galaxies are millions of light-years apart. Galaxies are the building blocks of our universe. Their distribution isn’t random, as one might suppose. Instead, galaxies reside along unimaginably long filaments across the universe, forming a cosmic web of star cities.
View larger. | Have you ever wondered what a galaxy is or how many galaxies are in the universe? Here’s the Webb telescope’s 1st deep field, released in July 2022. This near-infrared image of the galaxy cluster SMACS 0723 contains thousands of galaxies. High-resolution imaging from Webb – combined with a natural effect known as gravitational lensing – made this finely detailed image possible. Image via NASA/ ESA/ CSA/ STScI. Read more about this image.
A galaxy can contain hundreds of billions of stars and be many thousands of light-years across. Our own galaxy, the Milky Way, is around 100,000 light-years in diameter. That’s about 587,900 trillion miles, or nearly a million trillion kilometers.
The three types of galaxies are spiral, elliptical or irregular.
Galaxy sizes vary widely, ranging from very small to unbelievably enormous. Small dwarf galaxies contain about 100 million stars. Giant galaxies contain more than a trillion stars.
Also, there are an estimated two hundred billion galaxies in the universe.
Here is a closeup view of 1 small portion of a Webb image that shows more than 45,000 galaxies. Image via NASA/ ESA/ CSA/ Brant Robertson (UC Santa Cruz)/ Ben Johnson (CfA)/ Sandro Tacchella (Cambridge)/ Marcia Rieke (University of Arizona)/ Daniel Eisenstein (CfA)/ Alyssa Pagan (STScI).
The discovery of other galaxies
The famous astronomer Edwin P. Hubble first classified galaxies based on their visual appearance in the late 1920s and 30s. In fact, Hubble’s classification of galaxies remains in use today. Of course, since Hubble’s time, like any effective classification system, it has evolved from ongoing observations. Hubble identified several basic types of galaxies, each containing subtypes.
— Royal Astronomical Society (@RoyalAstroSoc) June 11, 2019
Before Hubble’s study of galaxies, we believed that our galaxy was the only one in the universe. Astronomers thought that the smudges of light they saw through their telescopes were in fact nebulae within our own galaxy. However, Hubble discovered that these nebulae were galaxies. Additionally, it was Hubble who demonstrated, by measuring their velocities, that they lie at vast distances from us.
Galaxies are light-years away
These galaxies lie millions of light-years beyond the Milky Way. The distances are so huge these galaxies appear tiny in all but the largest telescopes. Moreover, Hubble demonstrated that, wherever he looked, galaxies were receding from us in all directions. And the farther away they are, the faster they are receding. Thus, Hubble had discovered that the universe is expanding.
View at EarthSky Community Photos. | Harshwardhan Pathak of India, using a large remote telescope in Chile, captured the galaxy NGC 1232 in the constellation Eridanus on February 1, 2024. Harshwardhan wrote: “NGC 1232, also known as the Eye of God Galaxy, is an intermediate spiral galaxy about 60 million light-years away. German-British astronomer William Herschel discovered it on October 20, 1784.” Thank you, Harshwardhan!
Spiral galaxies
The most common type of galaxy is a spiral galaxy. The Milky Way is a spiral galaxy. Spiral galaxies have majestic, sweeping arms, thousands of light-years long. They contain millions upon millions of stars. Their spiral arms stand out because of bright stars, glowing gas and dust. Spiral galaxies are active with star formation.
Also, spiral galaxies have a bright center, made up of a dense concentration of stars. There are so many stars that from a distance the galaxy’s center looks like a solid ball. This ball of stars is known as the galactic bulge.
Also, there are two types of spiral galaxies. There are regular spirals and barred spirals. If the spiral has bars, they extend off the central bulge. Then, the spiral arms start at the end of the bar. In fact, the Milky Way Galaxy is a barred spiral galaxy.
The 3 most common types of galaxies. The top row shows schematic illustrations, and the bottom row shows actual images of galaxies that fit each of the 3 categories. Image via A. Feild/ STScI/ Hubblesite.
Elliptical and irregular galaxies
Elliptical galaxies are the universe’s largest galaxies. In fact, giant elliptical galaxies can be about 300,000 light-years across. But dwarf elliptical galaxies – the most common elliptical – are only a few thousand light-years across. There are several shapes of elliptical galaxies, ranging from circular to football-shaped.
Overall, 1/3 of all galaxies are elliptical galaxies. Elliptical galaxies contain very little gas and dust compared to a spiral or irregular galaxy. They are no longer actively forming stars. The stars in elliptical galaxies are older stars and contain very few heavier elements.
Irregular-shaped galaxies have all sorts of different shapes but they don’t look like a spiral or elliptical galaxy.
Irregular galaxies can have very little dust or a lot. Plus, they can show active star-forming regions or have little-to-no star formation occurring. They seemed plentiful in the early universe.
View larger. | This Hubble Space Telescope mosaic is of a portion of the immense Coma Berenices galaxy cluster. Be sure to use the view larger link and zoom in to see how much larger the football-shaped elliptical galaxies are, in contrast to the spiral galaxies. Image via NASA/ ESA/ J. Mack (STScI)/ J. Madrid (Australian Telescope National Facility).
Our Milky Way Galaxy
The Milky Way, in fact, falls into one of Hubble’s spiral galaxy sub-types. It’s a barred spiral, which means it has a bar of stars protruding out from each side of its center. As the spiral arms sweep out in their graceful and enormous arcs, the ends of the bars are the anchors. This is a recent discovery and it’s unknown how bars form in a galaxy. Our solar system is situated about 2/3 of the way out from the galactic center toward the periphery of the galaxy, embedded in one of these spiral arms.
Another recent discovery is that the disk of the Milky Way is warped, like a long-playing vinyl record left too long in the sun. Exactly why is unknown, but it may be the result of a gravitational encounter with another galaxy early in the Milky Way’s history.
It also appears that all galaxies rotate. For example, the Milky Way takes 226 million years to spin around once. Since its creation, the Earth has traveled 20 times around the galaxy.
Galaxies come in clusters
Galaxies group together in clusters. Our own galaxy is part of what is called the Local Group, and it contains at least 80 galaxies. The three large galaxies in the Local Group are the Andromeda Galaxy, the Milky Way Galaxy and the Triangulum Galaxy. The rest of the galaxies in our local group are dwarf galaxies.
The “glue” that binds stars into galaxies, galaxies into clusters, clusters into superclusters and superclusters into filaments is – of course – gravity. In fact, gravity is the universe’s construction worker, which sculpts all the structures we see in the cosmos.
The Universe is Infinite. However our existence in our current Galaxy Cluster is Finite. Time is also a factor… Our Galaxy Clusters actually expand into the void of space over time. pic.twitter.com/EAOcisPdZn
Most galaxies are flying apart from each other. But those astronomically close to each other will be gravitationally bound to each other. Caught in an inexorable gravitational dance, eventually they merge, passing through each other over millions of years. They eventually form a single, amorphous elliptical galaxy. Gravity shockwaves compress huge clouds of interstellar gas and dust during such mergers, giving rise to new generations of stars.
The Milky Way is caught in such a gravitational embrace with M31, aka the Andromeda Galaxy, which is 2 1/2 million light-years distant. Both galaxies are moving toward each other because of gravitational attraction: they will merge in about 6 billion years. However, huge halos of gas surround both galaxies and may extend for millions of light-years. And it was discovered that the halos of the Milky Way and M31 have already started to touch.
Galaxy mergers and companion galaxies
Galaxy mergers are common. The universe is full of examples of galaxies in various stages of merging together, their structures disrupted and distorted by gravity, forming bizarre and beautiful shapes.
Galaxies may take billions of years to fully merge into a single galaxy. As astronomers look outward in space, they can only see glimpses of this long merger process. Located 300 million light-years away in the constellation Coma Berenices, these 2 colliding galaxies have been nicknamed the Mice Galaxies because of the long tails of stars and gas emanating from each galaxy. Otherwise known as NGC 4676, the pair will eventually merge into a single giant galaxy. Image via NASA/ ESA/ Wikimedia Commons (public domain).
Then, at the lower end of the galactic size scale, there are so-called dwarf galaxies. They consist of a few hundred to up to several billion stars. Their origin is not clear. Typically, they have no clearly defined structure. Astronomers believe they were born in the same way as larger galaxies like the Milky Way, but for whatever reason they stopped growing. Ensnared by the gravity of a larger galaxy, they orbit its periphery. The Milky Way has around 60 dwarf galaxies orbiting it that we know of, although some models predict there should be many more.
The two most famous dwarf galaxies for us earthlings are, of course, the Large and Small Magellanic Clouds, visible to the unaided eye in Earth’s Southern Hemisphere sky.
Eventually, these and other dwarf galaxies will rip apart under the titanic pull of the Milky Way’s gravity. This will leave behind a barely noticeable stream of stars across the sky, slowly dissipating over eons.
The Large Magellanic Cloud spills across the border of Dorado and Mensa. The Small Magellanic Cloud is at lower left. Image via Yuri Beletsky/ LCO/ ESO.
Supermassive black holes lurk in galaxy centers
At the center of most galaxies lurks a supermassive black hole, of millions or even billions of solar masses. For example, TON 618, has a mass 66 billion times that of our sun. The one at the center of our own Milky Way galaxy possesses 4.6 million solar masses.
The origin and evolution of supermassive black holes remains a mystery. A few years ago, astronomers uncovered a surprising fact: in spiral galaxies, the mass of the supermassive black hole has a direct linear relationship with the mass of the galactic bulge. The more mass the black hole has, the more stars there are in the bulge. No one knows exactly what the significance of this relationship may be. However, its existence seems to indicate that the growth of a galaxy’s stellar population is linked to that of its supermassive black hole.
This discovery comes at a time when astronomers are beginning to realize that a supermassive black hole may control the fate of its host galaxy. The copious amount of electromagnetic radiation emitted from the maelstrom of material orbiting the central black hole. This is known as the accretion disk, and the radiation may push away and dissipate the clouds of interstellar hydrogen from which new stars form. This acts as an inhibitor on the galaxy’s ability to give birth to new stars. Ultimately, the activity of supermassive black holes may link to the emergence of life itself. This is an area that is undergoing extensive research.
While astronomers still know very little about exactly how galaxies formed in the first place – we see them in their nascent state only a few hundred million years after the Big Bang – the study of galaxies is an endless voyage of discovery.
We discovered other galaxies exist about a century ago
Around a hundred years ago we realized that other galaxies exist besides our own. Since then, we have learned so much about these grand, majestic star cities. And there is still much to learn.
Some galaxies from our EarthSky Community Photos
View at EarthSky Community Photos. | Shaurya Salunkhe in Velhe, Maharashtra, India, used a telephoto lens to capture this view of Messier 31, the Andromeda Galaxy, on January 11, 2026. Shaurya wrote: “I captured the Andromeda Galaxy, the Milky Way’s closest neighbor and the largest galaxy of the Local Group. This is the farthest object that is visible to the unaided eye. It’s 3 times larger than the Milky Way and is approximately 2.5 million light-years away. It is a fascinating target with stunning colours not to mention the bonus little galaxies (M32 and M110) near it.” Thank you, Shaurya!View at EarthSky Community Photos. | Andy Dungan near Cotopaxi, Colorado, captured this view of spiral galaxy IC 342, in the constellation Camelopardalis (also known as Caldwell 5), on June 22, 2025. Andy wrote: “This is really sort of the first of the winter galaxies. The challenge for taking pics of this galaxy is how dim it is compare to many others of its size. Evidently there is a substantial amount of dust someplace in between here and the 7-10 million light-years to the galaxy. As I said above more exposure and using PixInsight made a substantial difference in the quality of the pic. Ya, progress!!” Thank you, Andy!View at EarthSky Community Photos. | EarthSky’s own Marcy Curran in Cheyenne, Wyoming, captured the Pinwheel Galaxy on July 1, 2025. Marcy wrote: “The Pinwheel Galaxy (M101) is a face-on, counterclockwise intermediate spiral galaxy. It’s 21 million light-years from Earth in the constellation Ursa Major. It has a diameter of approximately 252,000 light-years and contains around one trillion stars. Pierre Méchain discovered it in 1781. Then Charles Messier verified its position before adding it to his Messier Catalog. It was 101 out of 110 deep-sky objects. The beautiful Pinwheel Galaxy is a near-perfect representation of a spiral galaxy.” Thank you, Marcy!
Bottom line: A galaxy is a vast island of gas, dust and stars in an ocean of space. There are three types of galaxies. Learn about these starry islands in space.
