Teapot of Sagittarius points to Milky Way center

Star chart: lines for Teapot, galactic equator and ecliptic, with galactic center and winter solstice marked.
The Teapot asterism in the constellation Sagittarius marks the direction in our sky to the center of our Milky Way galaxy. The green line marks the ecliptic, or sun’s path across our sky. And we’ve marked the winter solstice point, where the sun resides around December 21. Chart via EarthSky.

Come to know the Teapot of Sagittarius

Our Milky Way galaxy is a vast collection of hundreds of billions of stars. We’re not in the galaxy’s center, but instead about 2/3 of the way out from center, in one of the Milky Way’s spiral arms. On August evenings, all of us on Earth can gaze toward the galaxy’s center in a dark sky. In fact, the band of the Milky Way gets broader and brighter in the direction toward the center. Plus, in that direction, you’ll find a famous asterism called the Teapot, in the constellation Sagittarius.

The Teapot’s pattern is distinctive. Once you spot it, it’s easy to imagine as an earthly teapot. You’ll find it southward on August evenings from the Northern Hemisphere, and overhead from the Southern Hemisphere.

Even if your sky isn’t dark, once you find the Teapot, you can use it to guide your mind’s eye to the star-rich center of our galaxy. A supermassive black hole lies at the galaxy’s heart, with some 4 million times the mass of our sun. It’s called Sagittarius A* (Sagittarius A-Star).

How to spot the Teapot

You’ll want a fairly dark sky to find the Teapot (a suburban sky will likely work, if you’re not standing under a streetlight). You can see the Teapot even if you can’t see the starry band of the Milky Way. If you’re in the Northern Hemisphere, look southward on August evenings a couple of hours after sunset. If you’re in the Southern Hemisphere, look overhead.

The Teapot and Sagittarius are best viewed during the evening hours from about July to September.

Want a more exact location for Sagittarius? Try Stellarium, which will let you set a date and time from your exact location on the globe.

Star chart of Scorpius and Teapot with star Antares and point of galactic center marked in a long cloudy band.
The center of the galaxy is located between the Tail of Scorpius and the Teapot of Sagittarius. In a dark sky, you can see clouds of “steam” ascending from the Teapot’s spout in this region. Really, they are stars in our Milky Way galaxy. Chart via Astro Bob. Used with permission.

The Teapot looks like its name

The constellation of Sagittarius is supposed to be a centaur, a mythical half man/half horse creature, carrying a bow and arrow. But good luck spotting the centaur in these stars.

On the other hand, the Teapot – unlike many star patterns – looks like its namesake. That’s because the Teapot appears to have a handle, spout and lid, as any earthly teapot would. And just be sure to head to a dark sky for your best views of this Milky Way region.

Once you’ve found the Teapot, assuming you have a dark sky, you can see “steam” billowing out of the spout. Gaze into the midst of this “steam” – into the thickest part of it – and you’ll be gazing toward the center of our Milky Way galaxy.

The Teapot is highest in the evening sky in August

Because the sun passes in front of Sagittarius from about December 18 to January 20, the Teapot isn’t visible then. However, about half a year later – on July 1 – the Teapot climbs to its highest point for the night around midnight (1 a.m. daylight saving time or DST), when it appears due south as seen from the Northern Hemisphere or due north as seen from the Southern Hemisphere. In August, the Teapot – and the Milky Way center – reach their highest points for the night during the evening hours.

By the way, another noteworthy point lies in the direction of the Teapot in space. It’s the point at which the sun shines on the December solstice around December 21 each year.

The center of our Milky Way

The center of our galaxy is some 30,000 light-years away. We can’t see directly into it, because this region is shrouded by dust and gas clouds. But studies by astronomers have shown that, when we look in this direction, we’re looking toward the supermassive black hole located at our galaxy’s heart. This black hole has some 4 million times our sun’s mass. It’s known as Sagittarius A*.

Now sweep the area around the Teapot with binoculars or a telescope. You’ll see many faint fuzzy objects pop into view. They’re star clusters and nebulae (gas clouds) located in the disk of our galaxy, in the direction toward the galaxy’s center.

So, find the Teapot on a dark night – when the moon is out of the way – and enjoy all it has to offer.

Night sky photo with cloudy band of Milky Way, clusters and nebulae labeled, plus lines drawn for Teapot.
View at EarthSky Community Photos. | Catherine Hyde in Cambria, California, captured this photo of the Milky Way on July 10, 2023. Catherine wrote: “This is the Teapot asterism rising from behind a tree. I’ve heard if you can capture the galactic center (Milky Way) behind it, it looks like steam coming out of the spout. I was surprised by how many deep-sky objects I had captured, so I annotated the image.” Thank you, Catherine!

Bottom line: As you gaze toward the famous Teapot asterism in the constellation Sagittarius, you’re looking toward the center of our Milky Way galaxy.

The post Teapot of Sagittarius points to Milky Way center first appeared on EarthSky.



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Star chart: lines for Teapot, galactic equator and ecliptic, with galactic center and winter solstice marked.
The Teapot asterism in the constellation Sagittarius marks the direction in our sky to the center of our Milky Way galaxy. The green line marks the ecliptic, or sun’s path across our sky. And we’ve marked the winter solstice point, where the sun resides around December 21. Chart via EarthSky.

Come to know the Teapot of Sagittarius

Our Milky Way galaxy is a vast collection of hundreds of billions of stars. We’re not in the galaxy’s center, but instead about 2/3 of the way out from center, in one of the Milky Way’s spiral arms. On August evenings, all of us on Earth can gaze toward the galaxy’s center in a dark sky. In fact, the band of the Milky Way gets broader and brighter in the direction toward the center. Plus, in that direction, you’ll find a famous asterism called the Teapot, in the constellation Sagittarius.

The Teapot’s pattern is distinctive. Once you spot it, it’s easy to imagine as an earthly teapot. You’ll find it southward on August evenings from the Northern Hemisphere, and overhead from the Southern Hemisphere.

Even if your sky isn’t dark, once you find the Teapot, you can use it to guide your mind’s eye to the star-rich center of our galaxy. A supermassive black hole lies at the galaxy’s heart, with some 4 million times the mass of our sun. It’s called Sagittarius A* (Sagittarius A-Star).

How to spot the Teapot

You’ll want a fairly dark sky to find the Teapot (a suburban sky will likely work, if you’re not standing under a streetlight). You can see the Teapot even if you can’t see the starry band of the Milky Way. If you’re in the Northern Hemisphere, look southward on August evenings a couple of hours after sunset. If you’re in the Southern Hemisphere, look overhead.

The Teapot and Sagittarius are best viewed during the evening hours from about July to September.

Want a more exact location for Sagittarius? Try Stellarium, which will let you set a date and time from your exact location on the globe.

Star chart of Scorpius and Teapot with star Antares and point of galactic center marked in a long cloudy band.
The center of the galaxy is located between the Tail of Scorpius and the Teapot of Sagittarius. In a dark sky, you can see clouds of “steam” ascending from the Teapot’s spout in this region. Really, they are stars in our Milky Way galaxy. Chart via Astro Bob. Used with permission.

The Teapot looks like its name

The constellation of Sagittarius is supposed to be a centaur, a mythical half man/half horse creature, carrying a bow and arrow. But good luck spotting the centaur in these stars.

On the other hand, the Teapot – unlike many star patterns – looks like its namesake. That’s because the Teapot appears to have a handle, spout and lid, as any earthly teapot would. And just be sure to head to a dark sky for your best views of this Milky Way region.

Once you’ve found the Teapot, assuming you have a dark sky, you can see “steam” billowing out of the spout. Gaze into the midst of this “steam” – into the thickest part of it – and you’ll be gazing toward the center of our Milky Way galaxy.

The Teapot is highest in the evening sky in August

Because the sun passes in front of Sagittarius from about December 18 to January 20, the Teapot isn’t visible then. However, about half a year later – on July 1 – the Teapot climbs to its highest point for the night around midnight (1 a.m. daylight saving time or DST), when it appears due south as seen from the Northern Hemisphere or due north as seen from the Southern Hemisphere. In August, the Teapot – and the Milky Way center – reach their highest points for the night during the evening hours.

By the way, another noteworthy point lies in the direction of the Teapot in space. It’s the point at which the sun shines on the December solstice around December 21 each year.

The center of our Milky Way

The center of our galaxy is some 30,000 light-years away. We can’t see directly into it, because this region is shrouded by dust and gas clouds. But studies by astronomers have shown that, when we look in this direction, we’re looking toward the supermassive black hole located at our galaxy’s heart. This black hole has some 4 million times our sun’s mass. It’s known as Sagittarius A*.

Now sweep the area around the Teapot with binoculars or a telescope. You’ll see many faint fuzzy objects pop into view. They’re star clusters and nebulae (gas clouds) located in the disk of our galaxy, in the direction toward the galaxy’s center.

So, find the Teapot on a dark night – when the moon is out of the way – and enjoy all it has to offer.

Night sky photo with cloudy band of Milky Way, clusters and nebulae labeled, plus lines drawn for Teapot.
View at EarthSky Community Photos. | Catherine Hyde in Cambria, California, captured this photo of the Milky Way on July 10, 2023. Catherine wrote: “This is the Teapot asterism rising from behind a tree. I’ve heard if you can capture the galactic center (Milky Way) behind it, it looks like steam coming out of the spout. I was surprised by how many deep-sky objects I had captured, so I annotated the image.” Thank you, Catherine!

Bottom line: As you gaze toward the famous Teapot asterism in the constellation Sagittarius, you’re looking toward the center of our Milky Way galaxy.

The post Teapot of Sagittarius points to Milky Way center first appeared on EarthSky.



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Moon and Saturn close together this week. See the images!

On August 20, 2024, for all of us around the globe, the moon was up by about an hour after sunset and hung near Saturn in the sky. It occulted – or passed in front of – Saturn for observers from Latin America and the Caribbean, Africa and Europe at 3 UTC on August 21. Enjoy this gallery from our talented community of photographers. Also, notice the moon’s brightness. It looks so bright because it was just one day past Monday’s supermoon! For more sky events, visit EarthSky’s night sky guide or watch a 1-minute video about the moon and Saturn. And on the topic of Saturn … did you know its rings are disappearing?

Images of the occultation

Top left of a dark gray sphere. There is a small, brownish sphere hidding behind it to its left.
View at EarthSky Community photos. | Egidio Vergani of Italy shared this image of the moon and Saturn and wrote: “Saturn goes behind the moon. The moment in which the ringed planet hides behind our satellite to reappear after about an hour. The wonder of an occultation taken from Milan on August 21, 2024, at 4.30 am.” Thank you!
Moon and Satur: Top left of a dark gray sphere. There is a small, brownish sphere to its left that has a ring around.
View at EarthSky Community photos. | Egidio Vergani also captured this image, at 5:30 am, and wrote: “Exciting occultation of Saturn by the moon.” Thank you!
Top left of a gray sphere with some dark gray areas. There is a small, brownish sphere to its left that has a ring around.
View at EarthSky Community photos. | Makrem Larnaout from Tunisia shared this image and wrote: “The moon is presented as a 12-panel mosaic, each panel composed of 10% of 2K frames. Saturn was meticulously processed using 8 x 5K video captures, with 35% of the frames stacked and derotated to match the exact time, with the last capture just before ingress. The final composition is a single 15ms exposure taken during the event.” Thank you!
Whitish top left of a sphere. There is a faint sphere with a ring to its left side.
View at EarthSky Community photos. | Roberto Ortu from Cabras, Italy, captured this image and wrote: “On the morning of August 21, 2024, at 5:31 local time, the occultation of Saturn by the moon occurred. This is an image of me taken from a video in which the lunar rim and the planet were almost “in contact” just before the beginning of the phenomenon. You can see the great difference in brightness and apparent size of the 2 celestial bodies, with Saturn being many times larger but also vastly more distant than our satellite. The event lasted about an hour.” Thank you!

Images of the moon and Saturn

Bright white sphere with some darker areas in the middle. There is a small dot above the sphere.
View at EarthSky Community photos. | Felton Davis also photographed the moon and Saturn from New York City, but from that location, the occultation wasn’t visible. Felton wrote: “Cellphone photo through an 8-inch Orion reflector, cropped but not touched up. Saturn remained 1 degree from the moon, there was no occultation.” Thank you!
Top right of a white, bright sphere with a big, dark area close to the edge. There is a small dot at the top of the image.
View at EarthSky Community photos. | Steven Sweet from Mississauga, Ontario, Canada, captured Saturn above the moon’s Mare Crisium. Thank you!
Pale white sphere with some dark areas and a small dot in the distance, to the top right of the image.
View at EarthSky Community photos. | Chuck Reinhart from Vincennes, Indiana, wrote: “I increased the exposure in one photo to highlight Saturn and then decreased the exposure in the same photo to show the details of the moon.” Thank you!
Wrinkled surface at bottom right. A brown sphere with a ring around it at top left.
View at EarthSky Community photos. | John Van Allen from Santo Domingo, Dominican Republic, captured this image and wrote: “This was the best of about 20 tries by hand.” Thank you!

Bottom line: Did you miss the moon and Saturn close together on August 20, 2024? Here’s a gallery full of images of the event.

The post Moon and Saturn close together this week. See the images! first appeared on EarthSky.



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On August 20, 2024, for all of us around the globe, the moon was up by about an hour after sunset and hung near Saturn in the sky. It occulted – or passed in front of – Saturn for observers from Latin America and the Caribbean, Africa and Europe at 3 UTC on August 21. Enjoy this gallery from our talented community of photographers. Also, notice the moon’s brightness. It looks so bright because it was just one day past Monday’s supermoon! For more sky events, visit EarthSky’s night sky guide or watch a 1-minute video about the moon and Saturn. And on the topic of Saturn … did you know its rings are disappearing?

Images of the occultation

Top left of a dark gray sphere. There is a small, brownish sphere hidding behind it to its left.
View at EarthSky Community photos. | Egidio Vergani of Italy shared this image of the moon and Saturn and wrote: “Saturn goes behind the moon. The moment in which the ringed planet hides behind our satellite to reappear after about an hour. The wonder of an occultation taken from Milan on August 21, 2024, at 4.30 am.” Thank you!
Moon and Satur: Top left of a dark gray sphere. There is a small, brownish sphere to its left that has a ring around.
View at EarthSky Community photos. | Egidio Vergani also captured this image, at 5:30 am, and wrote: “Exciting occultation of Saturn by the moon.” Thank you!
Top left of a gray sphere with some dark gray areas. There is a small, brownish sphere to its left that has a ring around.
View at EarthSky Community photos. | Makrem Larnaout from Tunisia shared this image and wrote: “The moon is presented as a 12-panel mosaic, each panel composed of 10% of 2K frames. Saturn was meticulously processed using 8 x 5K video captures, with 35% of the frames stacked and derotated to match the exact time, with the last capture just before ingress. The final composition is a single 15ms exposure taken during the event.” Thank you!
Whitish top left of a sphere. There is a faint sphere with a ring to its left side.
View at EarthSky Community photos. | Roberto Ortu from Cabras, Italy, captured this image and wrote: “On the morning of August 21, 2024, at 5:31 local time, the occultation of Saturn by the moon occurred. This is an image of me taken from a video in which the lunar rim and the planet were almost “in contact” just before the beginning of the phenomenon. You can see the great difference in brightness and apparent size of the 2 celestial bodies, with Saturn being many times larger but also vastly more distant than our satellite. The event lasted about an hour.” Thank you!

Images of the moon and Saturn

Bright white sphere with some darker areas in the middle. There is a small dot above the sphere.
View at EarthSky Community photos. | Felton Davis also photographed the moon and Saturn from New York City, but from that location, the occultation wasn’t visible. Felton wrote: “Cellphone photo through an 8-inch Orion reflector, cropped but not touched up. Saturn remained 1 degree from the moon, there was no occultation.” Thank you!
Top right of a white, bright sphere with a big, dark area close to the edge. There is a small dot at the top of the image.
View at EarthSky Community photos. | Steven Sweet from Mississauga, Ontario, Canada, captured Saturn above the moon’s Mare Crisium. Thank you!
Pale white sphere with some dark areas and a small dot in the distance, to the top right of the image.
View at EarthSky Community photos. | Chuck Reinhart from Vincennes, Indiana, wrote: “I increased the exposure in one photo to highlight Saturn and then decreased the exposure in the same photo to show the details of the moon.” Thank you!
Wrinkled surface at bottom right. A brown sphere with a ring around it at top left.
View at EarthSky Community photos. | John Van Allen from Santo Domingo, Dominican Republic, captured this image and wrote: “This was the best of about 20 tries by hand.” Thank you!

Bottom line: Did you miss the moon and Saturn close together on August 20, 2024? Here’s a gallery full of images of the event.

The post Moon and Saturn close together this week. See the images! first appeared on EarthSky.



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Female sharks gather under sea to … sleep?


The video footage above, captured from a remotely operated underwater vehicle, shows the Fort Jackson sharks. Scientists spied thousands of them resting on the seafloor.

  • Thousands of sharks were spotted sleeping on the seafloor off the coast of southern Australia.
  • All the sharks were female; the scientists don’t know why.
  • An underwater robot vehicle spotted the sharks, using cameras that help scientists see what’s happening on the ocean floor.

Thousands of sharks spotted resting on seafloor

On August 13, 2024, while wrapping up a two-week expedition off the southern Australia coast, scientists using a remotely operated underwater vehicle stumbled upon thousands of sharks asleep on the seafloor. Notably, the Port Jackson sharks all appeared to be female. It was the second time in six years that scientists at Australia’s Beagle Marine Park have seen and documented them in the midst of an all-girl shark slumber party.

The scientists announced their extraordinary find in an August 14 statement. Expedition leader, Jacquomo Monk, of the University of Tasmania, said:

We had been hoping to see the sharks again on this survey. Coming upon them twice in a 3,000-square-kilometer [1,158 square miles] park is like finding a needle in a haystack.

It was very exciting when we managed to traverse over a rise in the reef to get a glimpse of the sharks snoozing 65 meters [213 feet] below the vessel in almost the same location as they were six years ago.

These scientists were conducting a survey of undersea life at the Beagle Marine Park in Australia, located in the central Bass Strait, between Tasmania and Victoria.

They were using a remotely operated vehicle, an underwater robot equipped with seven cameras, to image the seafloor.

Six sharks resting on a sandy seafloor. The sharks are light brown with dark streaks.
A close-up view of several Port Jackson sharks asleep on the seafloor at Beagle Marine Park. Image via NESP-IMAS.

What are they doing?!

This gathering of sharks was, as mentioned before, observed at Beagle Marine Park in southern Australia waters. It is a rocky reef habitat with sponge gardens. Islands in the park are also important breeding grounds for seabirds. So what are the sharks doing, sleeping under the sea in that area? Monk commented about an important clue:

One of the interesting things we discovered this time is that the Beagle gathering appears to be only for females.

This poses more questions than answers for us, but we know that the males and females of this species often live apart, except when mating.

We don’t know exactly why the females are here. Perhaps they are feasting on the local delicacy – doughboy scallops – before the long trip north to lay their eggs.

Seeing them again does tell us that the area is important to them.


An interview (3 min 12 s) with expedition leader Jacquomo Monk about the Port Jackson sharks seen at Beagle Marine Park.

More about Port Jackson sharks

Port Jackson sharks are found in coastal waters off southern Australia. These strikingly patterned bottom-dwelling sharks, that grow to about 5.5 feet (1.7 meters) in length, are primarily active at night. They feed on octopuses, squid, mollusks and crustaceans, and are usually found at depths of about 330 feet (100 meters).

Also, they breed in shallow waters off the coast of New South Wales and Victoria in late winter (late August to mid-November), where they’re often spotted by divers. There, the female sharks attach intricate spiral-shaped egg cases to the reef. It takes about 10 to 11 months for hatchlings to emerge.

A dark brown spiral object on white sand.
A Port Jackson shark case washed up on a beach. Image via Kate Bunker / Flickr.

Bottom line: Scientists recently observed thousands of Port Jackson sharks, all female, sleeping on the seafloor off south Australia.

Via Australian National Environmental Science Program

Read more: 12 shark facts that might surprise you

The post Female sharks gather under sea to … sleep? first appeared on EarthSky.



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The video footage above, captured from a remotely operated underwater vehicle, shows the Fort Jackson sharks. Scientists spied thousands of them resting on the seafloor.

  • Thousands of sharks were spotted sleeping on the seafloor off the coast of southern Australia.
  • All the sharks were female; the scientists don’t know why.
  • An underwater robot vehicle spotted the sharks, using cameras that help scientists see what’s happening on the ocean floor.

Thousands of sharks spotted resting on seafloor

On August 13, 2024, while wrapping up a two-week expedition off the southern Australia coast, scientists using a remotely operated underwater vehicle stumbled upon thousands of sharks asleep on the seafloor. Notably, the Port Jackson sharks all appeared to be female. It was the second time in six years that scientists at Australia’s Beagle Marine Park have seen and documented them in the midst of an all-girl shark slumber party.

The scientists announced their extraordinary find in an August 14 statement. Expedition leader, Jacquomo Monk, of the University of Tasmania, said:

We had been hoping to see the sharks again on this survey. Coming upon them twice in a 3,000-square-kilometer [1,158 square miles] park is like finding a needle in a haystack.

It was very exciting when we managed to traverse over a rise in the reef to get a glimpse of the sharks snoozing 65 meters [213 feet] below the vessel in almost the same location as they were six years ago.

These scientists were conducting a survey of undersea life at the Beagle Marine Park in Australia, located in the central Bass Strait, between Tasmania and Victoria.

They were using a remotely operated vehicle, an underwater robot equipped with seven cameras, to image the seafloor.

Six sharks resting on a sandy seafloor. The sharks are light brown with dark streaks.
A close-up view of several Port Jackson sharks asleep on the seafloor at Beagle Marine Park. Image via NESP-IMAS.

What are they doing?!

This gathering of sharks was, as mentioned before, observed at Beagle Marine Park in southern Australia waters. It is a rocky reef habitat with sponge gardens. Islands in the park are also important breeding grounds for seabirds. So what are the sharks doing, sleeping under the sea in that area? Monk commented about an important clue:

One of the interesting things we discovered this time is that the Beagle gathering appears to be only for females.

This poses more questions than answers for us, but we know that the males and females of this species often live apart, except when mating.

We don’t know exactly why the females are here. Perhaps they are feasting on the local delicacy – doughboy scallops – before the long trip north to lay their eggs.

Seeing them again does tell us that the area is important to them.


An interview (3 min 12 s) with expedition leader Jacquomo Monk about the Port Jackson sharks seen at Beagle Marine Park.

More about Port Jackson sharks

Port Jackson sharks are found in coastal waters off southern Australia. These strikingly patterned bottom-dwelling sharks, that grow to about 5.5 feet (1.7 meters) in length, are primarily active at night. They feed on octopuses, squid, mollusks and crustaceans, and are usually found at depths of about 330 feet (100 meters).

Also, they breed in shallow waters off the coast of New South Wales and Victoria in late winter (late August to mid-November), where they’re often spotted by divers. There, the female sharks attach intricate spiral-shaped egg cases to the reef. It takes about 10 to 11 months for hatchlings to emerge.

A dark brown spiral object on white sand.
A Port Jackson shark case washed up on a beach. Image via Kate Bunker / Flickr.

Bottom line: Scientists recently observed thousands of Port Jackson sharks, all female, sleeping on the seafloor off south Australia.

Via Australian National Environmental Science Program

Read more: 12 shark facts that might surprise you

The post Female sharks gather under sea to … sleep? first appeared on EarthSky.



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The return of Sirius in the morning signals seasonal change

Orion and Sirius: Star chart: Morning sky in August with Sirius and constellation Orion above it and stars labeled.
Here’s an early morning sight you won’t want to miss. The return of Sirius and the winter constellations to the morning sky heralds a change of season. Chart via EarthSky.

In late August and early September, look for two hints of the changing season in the predawn sky: Orion the Hunter and Sirius the Dog Star. Orion is easily recognizable by the short straight line of three bright stars that make up his Belt. It rises before dawn at this time of year. And the sky’s brightest star, Sirius – also known as the Dog Star, in the constellation Canis Major the Greater Dog – follows Orion into the sky as the predawn darkness gives way to dawn.

Have you noticed a very bright, madly twinkling star in this part of the early morning sky? Many do at this time of year. That star is Sirius. It’s so bright that, when it’s low in the sky, it shines with glints of red and flashes of blue. That’s the effect of our thick atmosphere causing its light to twinkle.

You won’t see Orion and Sirius in the evening sky until northern winter (or southern summer). But presently, the Hunter and the Dog Star lord over the sky at dawn.

Stars and constellations pass behind the sun

Orion was low in the west after sunset around March and April. By June of each year, the Hunter lies behind the sun as seen from Earth. Orion only returned to visibility in Earth’s sky about a month ago. Once a constellation becomes visible again, after being behind the sun, it always appears in the east before sunrise.

That’s because – as Earth moves around the sun – all stars rise two hours earlier with each passing month. So Orion is now higher at dawn than it was a month ago.

As seen from the Northern Hemisphere, Orion precedes Sirius into the sky. After Orion first appears at dawn, you can count on Sirius to appear in the morning sky a few weeks later.

Palm trees under a starry sky, including Orion and a bright dot above the trees, Sirius.
View at EarthSky Community Photos. | Nikunj Rawal in Gir National Park, India, captured this photo of Orion in November. Note the brightest star at the bottom, Sirius. Thank you, Nikunj!

The heliacal rising of Sirius

Now will be a good time to look for the heliacal rising of Sirius. In other words, what is the first date that you can see Sirius, with the unaided eye, in your morning sky? It depends on your latitude.

Below are a couple of graphs showing when you can expect to first see Sirius in your eastern predawn sky. They are designed for average eyesight, average weather and from near sea level.

Graph with arcing line of dots, latitude on Y axis and dates across the bottom.
The heliacal rising of Sirius from latitudes 70 degrees to -20 degrees. Philadelphia, for example, is at 40 degrees north latitude, so it will see Sirius reappear in the morning sky around August 17. Based upon calculations by Culture Diff’. Graph via Don Machholz.
Graph with line of dots arcing up to the right. Date on the x axis and latitude on the y axis.
The heliacal rising of Sirius from latitudes 60 degrees to 10 degrees. Based upon calculations by Culture Diff’. Graph via Don Machholz.

The return of Sirius and the colors of the stars

With Sirius and the stars of Orion low in your sky, you might notice that their light shimmers in various colors. But it’s not the stars that are changing; this is the prismatic effect of Earth’s atmosphere. As seen through a greater-than-usual thickness of atmosphere in the direction of the horizon, the mostly white light of Sirius can be broken up into striking colors on a summer morning.

But stars can be intrinsically colorful, too. Be sure to notice the reddish color of Betelgeuse when you watch Orion rise in these late summer months.

Long green line of a meteor above a beach, with constellation Orion bright star Sirius below it.
View at EarthSky Community Photos. | Daniel Friedman captured this beautiful shot from Montauk, New York, in December 2020. Note how bright Sirius is on the left, and how its color contrasts with the star Betelgeuse in the top left corner. Daniel wrote: “Out on the beach late with no one around for miles. Never captured a bolt like this and have been chasing meteor showers for years and years.” Thank you, Daniel!

Bottom line: A sign of the changing season is the return of Sirius before sunup. Be the first from your latitude to see Sirius in the morning sky.

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The post The return of Sirius in the morning signals seasonal change first appeared on EarthSky.



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Orion and Sirius: Star chart: Morning sky in August with Sirius and constellation Orion above it and stars labeled.
Here’s an early morning sight you won’t want to miss. The return of Sirius and the winter constellations to the morning sky heralds a change of season. Chart via EarthSky.

In late August and early September, look for two hints of the changing season in the predawn sky: Orion the Hunter and Sirius the Dog Star. Orion is easily recognizable by the short straight line of three bright stars that make up his Belt. It rises before dawn at this time of year. And the sky’s brightest star, Sirius – also known as the Dog Star, in the constellation Canis Major the Greater Dog – follows Orion into the sky as the predawn darkness gives way to dawn.

Have you noticed a very bright, madly twinkling star in this part of the early morning sky? Many do at this time of year. That star is Sirius. It’s so bright that, when it’s low in the sky, it shines with glints of red and flashes of blue. That’s the effect of our thick atmosphere causing its light to twinkle.

You won’t see Orion and Sirius in the evening sky until northern winter (or southern summer). But presently, the Hunter and the Dog Star lord over the sky at dawn.

Stars and constellations pass behind the sun

Orion was low in the west after sunset around March and April. By June of each year, the Hunter lies behind the sun as seen from Earth. Orion only returned to visibility in Earth’s sky about a month ago. Once a constellation becomes visible again, after being behind the sun, it always appears in the east before sunrise.

That’s because – as Earth moves around the sun – all stars rise two hours earlier with each passing month. So Orion is now higher at dawn than it was a month ago.

As seen from the Northern Hemisphere, Orion precedes Sirius into the sky. After Orion first appears at dawn, you can count on Sirius to appear in the morning sky a few weeks later.

Palm trees under a starry sky, including Orion and a bright dot above the trees, Sirius.
View at EarthSky Community Photos. | Nikunj Rawal in Gir National Park, India, captured this photo of Orion in November. Note the brightest star at the bottom, Sirius. Thank you, Nikunj!

The heliacal rising of Sirius

Now will be a good time to look for the heliacal rising of Sirius. In other words, what is the first date that you can see Sirius, with the unaided eye, in your morning sky? It depends on your latitude.

Below are a couple of graphs showing when you can expect to first see Sirius in your eastern predawn sky. They are designed for average eyesight, average weather and from near sea level.

Graph with arcing line of dots, latitude on Y axis and dates across the bottom.
The heliacal rising of Sirius from latitudes 70 degrees to -20 degrees. Philadelphia, for example, is at 40 degrees north latitude, so it will see Sirius reappear in the morning sky around August 17. Based upon calculations by Culture Diff’. Graph via Don Machholz.
Graph with line of dots arcing up to the right. Date on the x axis and latitude on the y axis.
The heliacal rising of Sirius from latitudes 60 degrees to 10 degrees. Based upon calculations by Culture Diff’. Graph via Don Machholz.

The return of Sirius and the colors of the stars

With Sirius and the stars of Orion low in your sky, you might notice that their light shimmers in various colors. But it’s not the stars that are changing; this is the prismatic effect of Earth’s atmosphere. As seen through a greater-than-usual thickness of atmosphere in the direction of the horizon, the mostly white light of Sirius can be broken up into striking colors on a summer morning.

But stars can be intrinsically colorful, too. Be sure to notice the reddish color of Betelgeuse when you watch Orion rise in these late summer months.

Long green line of a meteor above a beach, with constellation Orion bright star Sirius below it.
View at EarthSky Community Photos. | Daniel Friedman captured this beautiful shot from Montauk, New York, in December 2020. Note how bright Sirius is on the left, and how its color contrasts with the star Betelgeuse in the top left corner. Daniel wrote: “Out on the beach late with no one around for miles. Never captured a bolt like this and have been chasing meteor showers for years and years.” Thank you, Daniel!

Bottom line: A sign of the changing season is the return of Sirius before sunup. Be the first from your latitude to see Sirius in the morning sky.

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Delphinus the Dolphin has a graceful kite shape

Summer Triangle outlined with its apex stars labeled and 3 small constellations near it.
Once you’re familiar with the Summer Triangle, you can use it to star-hop to several nearby small constellations: Delphinus the Dolphin, Sagitta the Arrow and Vulpecula the Fox. Just be sure you’re looking in a dark sky! Chart via EarthSky.

How to see Delphinus

Delphinus the Dolphin is the 69th-smallest of the 88 constellations. It comes into view each year on northern summer evenings. And by northern fall, it’s well placed for viewing, arcing high across the sky each night. However, its stars are faint. So to see it, you’ll want a dark sky.

Delphinus lies just outside of the line connecting the stars Deneb in Cygnus the Swan and Altair in Aquila the Eagle. These bright stars form two corners of the famous asterism called the Summer Triangle. Scan along that line with your eye or binoculars. If your sky is dark enough, Delphinus will pop into view.

As a matter of fact, Delphinus looks very much like the animal it’s supposed to represent. Also, its faint stars form a kite shape with a tail. Then the little dolphin appears to leap out of the dark waters of the night sky.

Star chart of constellation Delphinus with 5 stars, 3 labeled.
A closeup on the constellation Delphinus the Dolphin and 3 of its named stars. Chart via EarthSky.

The stars of the Dolphin

The brightest star in the Dolphin is Beta Delphini, which shines at magnitude 3.6. The star also goes by the name Rotanev. Lying 101 light-years from Earth, it marks the point in the constellation where the Dolphin’s body connects with its tail.

The second brightest star is Alpha Delphini, at magnitude 3.7. This star nickname is Sualocin. Lying 254 light-years away, it marks the back of the Dolphin.

These two stars’ common names, Rotanev and Sualocin, are part of a puzzle. Italian astronomer Nicolaus Venator named these two stars. Can you solve the puzzle? Hint: try reading the stars’ names backward.

The nose of Delphinus is Gamma Delphini, a double star. The pair of stars shine at magnitude 4.2 and 5.1. They lie approximately 101 light-years away.

The belly of the dolphin is Delta Delphini, a magnitude 4.4 star lying 223 light-years away.

Although Delphinus is a small constellation, it contains an asterism: Job’s Coffin. The four stars that mark the body of the Dolphin are the same stars that form Job’s Coffin.

The tail of the dolphin contains one star, Epsilon Delphini or Aldulfin. The magnitude-4.0 star lies 330 light-years away.

In 2013, a bright nova exploded in Delphinus not far from Sualocin. The nova, V339 Delphini, was temporarily visible to the unaided eye.

Star field with labeled objects, and small bright dot circled in blue and labeled Nova.
This image of the night sky shows the region of Delphinus and the Summer Triangle where nova V339 briefly lit up in 2013. Image via NASA/ Wikimedia Commons (public domain).

Deep-sky objects

Most of the deep-sky objects in Delphinus are quite dim. The brightest of these is NGC 6934, a globular cluster found about 4 degrees out from the tail. NGC 6934 shines at magnitude 8.9. Another globular cluster, NGC 7006, lies off the nose of the Dolphin. If you draw a line from Sualocin through the nose star Gamma and extend it for about twice that distance, you’ll reach NGC 7006. NGC 7006 shines at magnitude 10.6.

Two planetary nebulae lie within the northwestern boundary of the constellation. Both are 12th magnitude. NGC 6905 – the Blue Flash Nebula – lies directly above the Dolphin’s back. The other planetary nebula – NGC 6891 – is above Delphinus’ tail. A number of galaxies are scattered about Delphinus; however, most of them are 12th magnitude and dimmer, making them very hard to spot without a large telescope.

Small, hazy light blue blob with barely perceptible features, in starfield.
The Blue Flash Nebula, NGC 6905, lies above the back of Delphinus the Dolphin. Image via Digital Sky Survey 2/ In-the-Sky.org/ Dominic Ford. Used with permission.

Delphinus and a neutrino

In 2021, scientists announced they’d pinpointed the origin of a neutrino, or high-energy particle. And it came from the direction of Delphinus the Dolphin.

They believe that, in a cataclysmic event, a supermassive black hole and a star drew too close together. The black hole shredded the star, which released the cosmic ray neutrino. Scientists detected the neutrino using the IceCube Neutrino Observatory at the Amundsen-Scott South Pole Station in Antarctica. So much info from such a tiny particle! Read more about the discovery.

Star chart with black stars on white of constellation Delphinus showing the outline and labels on the stars.
Star chart of the constellation Delphinus. Image by IAU/ Wikipedia (CC BY 3.0).

Delphinus in history and mythology

The name Delphinus means dolphin in Latin. But it was a Greek astronomer – Ptolemy of Alexandria in the second century CE – who first cataloged these stars. In Greek mythology, Delphinus represents the dolphin sent by the sea god Poseidon to fetch Amphitrite, a goddess of the sea and one of the fabled Nereids. It’s said Poseidon chose Amphitrite from among her sisters as they performed a dance on the isle of Naxos. The dolphin carried Amphitrite to Poseidon, and she became his wife. He rewarded the dolphin by making it a constellation.

In another story, Delphinus saves the Greek poet Arion when he is attacked by robbers on a ship. They were about to kill Arion, but he begged permission to sing a final song. His captors agreed, and the poet stood on the deck of the ship and sang a dirge accompanied by his lyre. He then threw himself overboard. A dolphin who’d heard his song and been charmed by the music saved him.

Antique colored etching an ugly fish next to a flying eagle, all scattered with stars.
In this drawing from Urania’s Mirror, Delphinus the Dolphin is the green sea creature at left. Image via Wikipedia (public domain).

Bottom line: Delphinus the Dolphin is a petite constellation that looks like the animal it’s supposed to represent. Look for the dolphin leaping under the Summer Triangle.

The post Delphinus the Dolphin has a graceful kite shape first appeared on EarthSky.



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Summer Triangle outlined with its apex stars labeled and 3 small constellations near it.
Once you’re familiar with the Summer Triangle, you can use it to star-hop to several nearby small constellations: Delphinus the Dolphin, Sagitta the Arrow and Vulpecula the Fox. Just be sure you’re looking in a dark sky! Chart via EarthSky.

How to see Delphinus

Delphinus the Dolphin is the 69th-smallest of the 88 constellations. It comes into view each year on northern summer evenings. And by northern fall, it’s well placed for viewing, arcing high across the sky each night. However, its stars are faint. So to see it, you’ll want a dark sky.

Delphinus lies just outside of the line connecting the stars Deneb in Cygnus the Swan and Altair in Aquila the Eagle. These bright stars form two corners of the famous asterism called the Summer Triangle. Scan along that line with your eye or binoculars. If your sky is dark enough, Delphinus will pop into view.

As a matter of fact, Delphinus looks very much like the animal it’s supposed to represent. Also, its faint stars form a kite shape with a tail. Then the little dolphin appears to leap out of the dark waters of the night sky.

Star chart of constellation Delphinus with 5 stars, 3 labeled.
A closeup on the constellation Delphinus the Dolphin and 3 of its named stars. Chart via EarthSky.

The stars of the Dolphin

The brightest star in the Dolphin is Beta Delphini, which shines at magnitude 3.6. The star also goes by the name Rotanev. Lying 101 light-years from Earth, it marks the point in the constellation where the Dolphin’s body connects with its tail.

The second brightest star is Alpha Delphini, at magnitude 3.7. This star nickname is Sualocin. Lying 254 light-years away, it marks the back of the Dolphin.

These two stars’ common names, Rotanev and Sualocin, are part of a puzzle. Italian astronomer Nicolaus Venator named these two stars. Can you solve the puzzle? Hint: try reading the stars’ names backward.

The nose of Delphinus is Gamma Delphini, a double star. The pair of stars shine at magnitude 4.2 and 5.1. They lie approximately 101 light-years away.

The belly of the dolphin is Delta Delphini, a magnitude 4.4 star lying 223 light-years away.

Although Delphinus is a small constellation, it contains an asterism: Job’s Coffin. The four stars that mark the body of the Dolphin are the same stars that form Job’s Coffin.

The tail of the dolphin contains one star, Epsilon Delphini or Aldulfin. The magnitude-4.0 star lies 330 light-years away.

In 2013, a bright nova exploded in Delphinus not far from Sualocin. The nova, V339 Delphini, was temporarily visible to the unaided eye.

Star field with labeled objects, and small bright dot circled in blue and labeled Nova.
This image of the night sky shows the region of Delphinus and the Summer Triangle where nova V339 briefly lit up in 2013. Image via NASA/ Wikimedia Commons (public domain).

Deep-sky objects

Most of the deep-sky objects in Delphinus are quite dim. The brightest of these is NGC 6934, a globular cluster found about 4 degrees out from the tail. NGC 6934 shines at magnitude 8.9. Another globular cluster, NGC 7006, lies off the nose of the Dolphin. If you draw a line from Sualocin through the nose star Gamma and extend it for about twice that distance, you’ll reach NGC 7006. NGC 7006 shines at magnitude 10.6.

Two planetary nebulae lie within the northwestern boundary of the constellation. Both are 12th magnitude. NGC 6905 – the Blue Flash Nebula – lies directly above the Dolphin’s back. The other planetary nebula – NGC 6891 – is above Delphinus’ tail. A number of galaxies are scattered about Delphinus; however, most of them are 12th magnitude and dimmer, making them very hard to spot without a large telescope.

Small, hazy light blue blob with barely perceptible features, in starfield.
The Blue Flash Nebula, NGC 6905, lies above the back of Delphinus the Dolphin. Image via Digital Sky Survey 2/ In-the-Sky.org/ Dominic Ford. Used with permission.

Delphinus and a neutrino

In 2021, scientists announced they’d pinpointed the origin of a neutrino, or high-energy particle. And it came from the direction of Delphinus the Dolphin.

They believe that, in a cataclysmic event, a supermassive black hole and a star drew too close together. The black hole shredded the star, which released the cosmic ray neutrino. Scientists detected the neutrino using the IceCube Neutrino Observatory at the Amundsen-Scott South Pole Station in Antarctica. So much info from such a tiny particle! Read more about the discovery.

Star chart with black stars on white of constellation Delphinus showing the outline and labels on the stars.
Star chart of the constellation Delphinus. Image by IAU/ Wikipedia (CC BY 3.0).

Delphinus in history and mythology

The name Delphinus means dolphin in Latin. But it was a Greek astronomer – Ptolemy of Alexandria in the second century CE – who first cataloged these stars. In Greek mythology, Delphinus represents the dolphin sent by the sea god Poseidon to fetch Amphitrite, a goddess of the sea and one of the fabled Nereids. It’s said Poseidon chose Amphitrite from among her sisters as they performed a dance on the isle of Naxos. The dolphin carried Amphitrite to Poseidon, and she became his wife. He rewarded the dolphin by making it a constellation.

In another story, Delphinus saves the Greek poet Arion when he is attacked by robbers on a ship. They were about to kill Arion, but he begged permission to sing a final song. His captors agreed, and the poet stood on the deck of the ship and sang a dirge accompanied by his lyre. He then threw himself overboard. A dolphin who’d heard his song and been charmed by the music saved him.

Antique colored etching an ugly fish next to a flying eagle, all scattered with stars.
In this drawing from Urania’s Mirror, Delphinus the Dolphin is the green sea creature at left. Image via Wikipedia (public domain).

Bottom line: Delphinus the Dolphin is a petite constellation that looks like the animal it’s supposed to represent. Look for the dolphin leaping under the Summer Triangle.

The post Delphinus the Dolphin has a graceful kite shape first appeared on EarthSky.



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Don’t miss it! Best Super Blue Moon images of 2024

Super Blue Moon
View at EarthSky Community Photos. | Bob Rich from Bryan, Texas, shared this image and wrote: “The August 2024 supermoon – and seasonal blue moon – rises behind a windmill.” Thank you!

Did you see the Super Blue Moon on Monday (August 19, 2024)? What a night it was for all of us around the world! If you didn’t, here’s a gallery full of stunning images from our talented community of photographers. Read more about the Blue Moon here. Also, three more supermoons are coming in a row. We tell you everything you need to know, plus tips on how to watch the moon, in this LIVESTREAM replay.

Super Blue Moon panoramas of 2024

View at EarthSky Community Photos. | Cecille Kennedy from Monroe, Oregon, shared this lovely view of the moon and wrote: “The glowing pink-orange moon rises over the pine trees and Saddle Mountain behind the trees. Thick clouds cover half of the moon, and soon the whole of it got covered with night fog and clouds.” Thank you, Cecille! Just in time.
View at EarthSky Community Photos. | Everybody around the world enjoyed the Super Blue Moon. José Palma shared this image from Belem, Portugal. Thank you, José!
View at EarthSky Community Photos. | Saqlain Haider from Pattoki, Punjab, Pakistan, shared this composite image and wrote: “Eighty-five images after every 15 seconds taken with the camera fixed on a tripod.” Wonderful! Thank you.
View at EarthSky Community Photos. | Kamala Venkatesh from San Diego, California, wrote: “The Super/ Sturgeon/ Blue full moon shot on August 18 as it rose over the homes near me. The August full moon will appear 6.2% bigger and 12.8% brighter than the average full moon. It sure was huge and very bright.” Thank you! The moon looks full the nights before and after the peak.

Super Blue Moon closeups of 2024

View at EarthSky Community Photos. | Talha Moon from Karachi, Sindh, Pakistan, shared this image and wrote: “The image showcases a Super Blue mineral moon. The term “supermoon” refers to as either a new or full moon that occurs when the moon is within 90% of its closest approach to Earth. Although it does not look blue, as the 3rd full moon in a season with 4 full moons, this is also a Blue Moon. Not to mention the exaggerated colors that show presence of minerals on the moon.” Thank you!
View at EarthSky Community Photos. | Kannan A shared this shot from Singapore, despite the cloudy skies. Thank you, Kannan!
View at EarthSky Community Photos. | Muhammad Alaa from Egypt shared this image and wrote: “Fifty photos of the moon were taken, I stacked the photos and edited them.” Thank you!

More Blue supermoon closeups

View at EarthSky Community Photos. | Tameem Altameemi from Dubai took this shot and wrote: “The 19 August 2024 full moon was both a supermoon and a Blue Moon, which is what makes this a ‘true Blue supermoon.'” Thank you!
View at EarthSky Community Photos. | Amr Elsayed shared this shot from Cairo, Egypt. Thank you, Amr!
View at EarthSky Community Photos. | Steven Bellavia from Mattituck, New York, shared this image and wrote: “The super full Sturgeon Blue Moon.” Thank you!

Bottom line: What a night it was for all of us around the world this Monday! Did you see the Super Blue Moon? If you didn’t, here’s a gallery full of stunning images from our talented community of photographers.

The post Don’t miss it! Best Super Blue Moon images of 2024 first appeared on EarthSky.



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Super Blue Moon
View at EarthSky Community Photos. | Bob Rich from Bryan, Texas, shared this image and wrote: “The August 2024 supermoon – and seasonal blue moon – rises behind a windmill.” Thank you!

Did you see the Super Blue Moon on Monday (August 19, 2024)? What a night it was for all of us around the world! If you didn’t, here’s a gallery full of stunning images from our talented community of photographers. Read more about the Blue Moon here. Also, three more supermoons are coming in a row. We tell you everything you need to know, plus tips on how to watch the moon, in this LIVESTREAM replay.

Super Blue Moon panoramas of 2024

View at EarthSky Community Photos. | Cecille Kennedy from Monroe, Oregon, shared this lovely view of the moon and wrote: “The glowing pink-orange moon rises over the pine trees and Saddle Mountain behind the trees. Thick clouds cover half of the moon, and soon the whole of it got covered with night fog and clouds.” Thank you, Cecille! Just in time.
View at EarthSky Community Photos. | Everybody around the world enjoyed the Super Blue Moon. José Palma shared this image from Belem, Portugal. Thank you, José!
View at EarthSky Community Photos. | Saqlain Haider from Pattoki, Punjab, Pakistan, shared this composite image and wrote: “Eighty-five images after every 15 seconds taken with the camera fixed on a tripod.” Wonderful! Thank you.
View at EarthSky Community Photos. | Kamala Venkatesh from San Diego, California, wrote: “The Super/ Sturgeon/ Blue full moon shot on August 18 as it rose over the homes near me. The August full moon will appear 6.2% bigger and 12.8% brighter than the average full moon. It sure was huge and very bright.” Thank you! The moon looks full the nights before and after the peak.

Super Blue Moon closeups of 2024

View at EarthSky Community Photos. | Talha Moon from Karachi, Sindh, Pakistan, shared this image and wrote: “The image showcases a Super Blue mineral moon. The term “supermoon” refers to as either a new or full moon that occurs when the moon is within 90% of its closest approach to Earth. Although it does not look blue, as the 3rd full moon in a season with 4 full moons, this is also a Blue Moon. Not to mention the exaggerated colors that show presence of minerals on the moon.” Thank you!
View at EarthSky Community Photos. | Kannan A shared this shot from Singapore, despite the cloudy skies. Thank you, Kannan!
View at EarthSky Community Photos. | Muhammad Alaa from Egypt shared this image and wrote: “Fifty photos of the moon were taken, I stacked the photos and edited them.” Thank you!

More Blue supermoon closeups

View at EarthSky Community Photos. | Tameem Altameemi from Dubai took this shot and wrote: “The 19 August 2024 full moon was both a supermoon and a Blue Moon, which is what makes this a ‘true Blue supermoon.'” Thank you!
View at EarthSky Community Photos. | Amr Elsayed shared this shot from Cairo, Egypt. Thank you, Amr!
View at EarthSky Community Photos. | Steven Bellavia from Mattituck, New York, shared this image and wrote: “The super full Sturgeon Blue Moon.” Thank you!

Bottom line: What a night it was for all of us around the world this Monday! Did you see the Super Blue Moon? If you didn’t, here’s a gallery full of stunning images from our talented community of photographers.

The post Don’t miss it! Best Super Blue Moon images of 2024 first appeared on EarthSky.



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Oceans of water on Mars deep underground?

Part of Mars with its orangish surface and white polar cap against a black background.
Mars in late 2023. New analysis of data from NASA’s InSight mission reveals possible oceans of liquid water on Mars, deep in the planet’s crust. Image via the Mars Express spacecraft/ ESA.
  • Mars probably had liquid water on its surface billions of years ago. But Mars’ water disappeared over time, leaving the planet cold and dry. Where did Mars’ water go?
  • Could water now lie below Mars’ surface? New research from from Scripps Institution of Oceanography – based on data from NASA’s InSight lander – suggests this possibility.
  • Mars’ underground water might be enough to form a global ocean, these scientists say, if it were on the surface.

Oceans of water on Mars, underground?

There is ample evidence today for liquid water on Mars a few billion years ago. But today’s Mars is a frozen desert. Where did its water go? A new study, led by Vashan Wright, a geophysicist at UC San Diego’s Scripps Institution of Oceanography, provides potential evidence of water – lots of it – deep below the surface in the crust. The findings are based on data from NASA’s now-defunct InSight mission. The researchers said on August 12, 2024, that Mars’ mid-crust may be saturated with water, enough to form a global ocean if that water were on the surface.

The researchers published their peer-reviewed study in the Proceedings of the National Academy of Sciences on August 12, 2024.

Wright posted the news on X on August 12:

Oceans of water on Mars?

Mars had rivers, lakes and possibly even oceans. But, billions of years ago, the planet lost all its surface water. Mars’ surface became dry, cold and inhospitable. Scientists have come up with hypotheses about where all the water went. There is evidence that some of it escaped into space. But much of it might also have simply seeped underground. The new findings – if confirmed – would seem to validate that possibility. As the paper stated:

Large volumes of liquid water transiently existed on the surface of Mars more than three billion years ago. Much of this water is hypothesized to have been sequestered in the subsurface or lost to space.

The new study says that most of Mars’ water is still underground today, and is liquid, not just ice. We already know of extensive ice deposits both on the surface at the poles and below the surface as well. This study, however, focuses on the mid-crust, deeper down than where the ice deposits are. The depth is between 7 to 13 miles (11 to 20 km). The data came from NASA’s InSight lander, which studied the Martian interior: the crust, mantle and core. These data, along with data from Mars rovers, help scientists understand how Mars evolved, how much water it once had and how much water may still exist. Wright said:

Understanding the Martian water cycle is critical for understanding the evolution of the climate, surface and interior. A useful starting point is to identify where water is and how much is there.

The study estimated there is enough water to fill a planet-wide ocean about 1 mile (1.6 km) deep.

Liquid water most likely explanation

InSight ended its mission in December 2022, after too much dust finally deprived the solar-powered lander of enough power. But during the four years it operated, it collected enormous amounts of data about the inside of Mars. This included detecting thousands of marsquakes, the equivalent of earthquakes on our planet. By measuring the speeds at which the seismic waves move below the surface, scientists can determine what kinds of rocks, ice or other material are present. The research team used a model informed by a mathematical theory of rock physics. The result? the researchers determined that the presence of liquid water in the crust most likely explained the data from InSight. The paper said:

A mid-crust composed of fractured igneous rocks saturated with liquid water best explains the existing data. Our results have implications for understanding Mars’ water cycle, determining the fates of past surface water, searching for past or extant life, and assessing in situ resource utilization for future missions. While available data are best explained by a water-saturated mid-crust, our results highlight the value of geophysical measurements and better constraints on the mineralogy and composition of Mars’ crust.

Warmer temperatures deep in the crust

While ice deposits are common in the near-surface of Mars, the potential liquid water is deeper down, in the mid-crust, where temperatures are warmer. The paper stated:

Liquid water in the pores of the mid-crust also requires high enough permeability and warm enough temperatures in the shallow crust to permit exchange between the surface and greater depths.

The researchers even postulate that there should be more water in the mid-crust zone than the amounts proposed to have filled the hypothesized ancient Martian oceans. That’s a lot of water!

Cutaway view of the interior of a planet, with labeled layers of crust shown.
Cutaway diagram of Mars’ interior based on data from the InSight mission. Image via James Tuttle Keane/ Aaron Rodriquez/ Scripps Institution of Oceanography.

A window to past Mars and possible home for life

If there really is an ocean’s worth of water inside Mars, then that provides fascinating clues about the planet’s past. Co-author Michael Manga of UC Berkeley said:

Establishing that there is a big reservoir of liquid water provides some window into what the climate was like or could be like. And water is necessary for life as we know it. I don’t see why [the underground reservoir] is not a habitable environment. It’s certainly true on Earth; deep, deep mines host life, the bottom of the ocean hosts life. We haven’t found any evidence for life on Mars, but at least we have identified a place that should, in principle, be able to sustain life.

Water on Mars: Complex robot-like machine with 2 large solar panels sitting on reddish sandy terrain, seen from above.
View larger. | This is the InSight lander’s 1st “selfie,” taken on December 6, 2018. Image via NASA/ JPL-Caltech.

Bottom line: Where did Mars’ water go? A new study using data from NASA’s InSight mission provides evidence for oceans of water on Mars, deep below the surface in the crust.

Source: Liquid water in the Martian mid-crust

Via Scripps Institution of Oceanography

Via UC Berkeley

Read more: To find water on Mars, listen to marsquakes

Read more: InSight Lander reveals 1st marsquakes on Mars

The post Oceans of water on Mars deep underground? first appeared on EarthSky.



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Part of Mars with its orangish surface and white polar cap against a black background.
Mars in late 2023. New analysis of data from NASA’s InSight mission reveals possible oceans of liquid water on Mars, deep in the planet’s crust. Image via the Mars Express spacecraft/ ESA.
  • Mars probably had liquid water on its surface billions of years ago. But Mars’ water disappeared over time, leaving the planet cold and dry. Where did Mars’ water go?
  • Could water now lie below Mars’ surface? New research from from Scripps Institution of Oceanography – based on data from NASA’s InSight lander – suggests this possibility.
  • Mars’ underground water might be enough to form a global ocean, these scientists say, if it were on the surface.

Oceans of water on Mars, underground?

There is ample evidence today for liquid water on Mars a few billion years ago. But today’s Mars is a frozen desert. Where did its water go? A new study, led by Vashan Wright, a geophysicist at UC San Diego’s Scripps Institution of Oceanography, provides potential evidence of water – lots of it – deep below the surface in the crust. The findings are based on data from NASA’s now-defunct InSight mission. The researchers said on August 12, 2024, that Mars’ mid-crust may be saturated with water, enough to form a global ocean if that water were on the surface.

The researchers published their peer-reviewed study in the Proceedings of the National Academy of Sciences on August 12, 2024.

Wright posted the news on X on August 12:

Oceans of water on Mars?

Mars had rivers, lakes and possibly even oceans. But, billions of years ago, the planet lost all its surface water. Mars’ surface became dry, cold and inhospitable. Scientists have come up with hypotheses about where all the water went. There is evidence that some of it escaped into space. But much of it might also have simply seeped underground. The new findings – if confirmed – would seem to validate that possibility. As the paper stated:

Large volumes of liquid water transiently existed on the surface of Mars more than three billion years ago. Much of this water is hypothesized to have been sequestered in the subsurface or lost to space.

The new study says that most of Mars’ water is still underground today, and is liquid, not just ice. We already know of extensive ice deposits both on the surface at the poles and below the surface as well. This study, however, focuses on the mid-crust, deeper down than where the ice deposits are. The depth is between 7 to 13 miles (11 to 20 km). The data came from NASA’s InSight lander, which studied the Martian interior: the crust, mantle and core. These data, along with data from Mars rovers, help scientists understand how Mars evolved, how much water it once had and how much water may still exist. Wright said:

Understanding the Martian water cycle is critical for understanding the evolution of the climate, surface and interior. A useful starting point is to identify where water is and how much is there.

The study estimated there is enough water to fill a planet-wide ocean about 1 mile (1.6 km) deep.

Liquid water most likely explanation

InSight ended its mission in December 2022, after too much dust finally deprived the solar-powered lander of enough power. But during the four years it operated, it collected enormous amounts of data about the inside of Mars. This included detecting thousands of marsquakes, the equivalent of earthquakes on our planet. By measuring the speeds at which the seismic waves move below the surface, scientists can determine what kinds of rocks, ice or other material are present. The research team used a model informed by a mathematical theory of rock physics. The result? the researchers determined that the presence of liquid water in the crust most likely explained the data from InSight. The paper said:

A mid-crust composed of fractured igneous rocks saturated with liquid water best explains the existing data. Our results have implications for understanding Mars’ water cycle, determining the fates of past surface water, searching for past or extant life, and assessing in situ resource utilization for future missions. While available data are best explained by a water-saturated mid-crust, our results highlight the value of geophysical measurements and better constraints on the mineralogy and composition of Mars’ crust.

Warmer temperatures deep in the crust

While ice deposits are common in the near-surface of Mars, the potential liquid water is deeper down, in the mid-crust, where temperatures are warmer. The paper stated:

Liquid water in the pores of the mid-crust also requires high enough permeability and warm enough temperatures in the shallow crust to permit exchange between the surface and greater depths.

The researchers even postulate that there should be more water in the mid-crust zone than the amounts proposed to have filled the hypothesized ancient Martian oceans. That’s a lot of water!

Cutaway view of the interior of a planet, with labeled layers of crust shown.
Cutaway diagram of Mars’ interior based on data from the InSight mission. Image via James Tuttle Keane/ Aaron Rodriquez/ Scripps Institution of Oceanography.

A window to past Mars and possible home for life

If there really is an ocean’s worth of water inside Mars, then that provides fascinating clues about the planet’s past. Co-author Michael Manga of UC Berkeley said:

Establishing that there is a big reservoir of liquid water provides some window into what the climate was like or could be like. And water is necessary for life as we know it. I don’t see why [the underground reservoir] is not a habitable environment. It’s certainly true on Earth; deep, deep mines host life, the bottom of the ocean hosts life. We haven’t found any evidence for life on Mars, but at least we have identified a place that should, in principle, be able to sustain life.

Water on Mars: Complex robot-like machine with 2 large solar panels sitting on reddish sandy terrain, seen from above.
View larger. | This is the InSight lander’s 1st “selfie,” taken on December 6, 2018. Image via NASA/ JPL-Caltech.

Bottom line: Where did Mars’ water go? A new study using data from NASA’s InSight mission provides evidence for oceans of water on Mars, deep below the surface in the crust.

Source: Liquid water in the Martian mid-crust

Via Scripps Institution of Oceanography

Via UC Berkeley

Read more: To find water on Mars, listen to marsquakes

Read more: InSight Lander reveals 1st marsquakes on Mars

The post Oceans of water on Mars deep underground? first appeared on EarthSky.



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