Concentrations of dangerous pollutants from rocket launches and satellite reentries in Earth's upper atmosphere might reach treacherous tipping points if constellations of hundreds of thousands of orbiting data centers get deployed in the next decade, experts say.

There's no question that Earth has an AI data center problem. By 2030, AI data centers may be responsible for up to 17% of electricity consumption in the U.S., according to a forecast by the Electric Power Research Institute. New fossil fuel power plants are being built to feed the growing demand for electricity, and aging ones are kept online despite decarbonization plans. On top of that, huge amounts of water are taken from already strained reservoirs to cool the computers.

Companies such as SpaceX, Amazon and Blue Origin say they have a solution: moving the power-hungry data crunching infrastructure into space, where solar power is easy to produce, and heat can be radiated out into the frigid vacuum. Combined, those companies have filed applications to the U.S. Federal Communications Commission to launch more than a million orbiting data centers in the next 10 years. Most of those will belong to SpaceX, if all goes to plan; Elon Musk has said the company wants to operate a million-satellite AI constellation all by itself.

The plans are making atmospheric scientists tear their hair out. If all these projects come to fruition, the number of satellites being launched to space and reentering the atmosphere will increase 100 times compared to today's numbers.

Moreover, the data center satellites will be much larger than the spacecraft orbiting Earth today. This large mass will translate into higher quantities of polluting propellant needed to loft these systems off Earth and a much larger amount of metals vaporizing in Earth's atmosphere during reentry. Neither is good news for our planet's air.

Pristine upper atmosphere

"Launches and the reentries are really the only things that humans do that deposit material directly into the upper atmosphere," Aaron Boley, an astronomy professor and space sustainability researcher at the University of British Columbia, told Space.com. "And the way things mix in the upper atmosphere means that the launch and reentry emissions are by far more impactful."

Most rockets emit black carbon, which could worsen global warming. Satellite bodies are mostly made of aluminum, which likely turns into aluminum oxide when burned in the presence of oxygen. Aluminum oxide is known for its ability to trigger ozone depletion, a hazardous process that was successfully thwarted by the Montreal Protocol of 1987.

Currently, scientists don't have a precise understanding of the chemical reactions that occur between the pollutants and the atmospheric gases at high altitudes. They also don't understand the tipping points, which may mean the difference between minor and major impacts on the climate. What is worse, pollutants in the upper atmosphere remain much longer than those emitted by cars and factory chimneys close to the ground.

"Close to the ground, we have rain and wind that removes pollution from the atmosphere within weeks," Eloise Marais, a professor of atmospheric chemistry at University College London, told Space.com. "If we put it into the higher layers of the atmosphere, we rely on very slow atmospheric processes to bring this pollution back down."

Too many launches

Black carbon from rockets, for example, can stay in the atmosphere for three years, scientists think, meaning its concentrations could dangerously rise in the near future.

SpaceX's Starship megarocket is likely to play a key role in the deployment of data center constellations. Unlike SpaceX's current workhorse launcher Falcon 9, which burns a form of the aviation fuel kerosene, Starship combusts the much cleaner combination of methane and liquid oxygen. But Marais cautions that Starship's size and the much more frequent launches that will be needed to deploy the vast constellations would result in an overall increase in the pollution injected into the upper atmosphere.

"Starship is a bigger rocket burning more propellant," Marais said. "So, in terms of each rocket launch, the difference almost offsets. It has potential per launch to produce quite similar amounts of black carbon."

Andrew Wilson, a space sustainability researcher at Glasgow Caledonia University in the U.K., told Space.com that every single Starship launch produces around 76,000 metric tons of carbon dioxide equivalent. That's about as much as 17,727 gasoline-powered passenger cars emit in a year.

And up to 77,000 Starship launches — some 15,300 per year — might be needed, according to estimates by Ars Technica, to deploy SpaceX's planned million-data-center constellation. That's a lot of rocket pollution added into the atmosphere. For comparison, there were just 324 orbital rocket liftoffs globally in 2025, according to Space News.

The space junk rain

Then there is the toxic ash from reentering satellites. Today, nearly 19,000 operational and defunct satellites orbit Earth, according to the European Space Agency. Currently, the most numerous type of satellite in Earth orbit is SpaceX's Starlink V2 Mini, each of which weighs about 1,760 pounds (800 kilograms). But SpaceX's orbital data centers are likely to be much more massive. Featuring solar arrays 246 feet (75 m) wide, every data center satellite might weigh up to 7.5 metric tonnes, according to available estimates.

Industry insiders expect that SpaceX and other providers would want to replace their AI satellites every five years with newer technology, as they do with existing communications satellites. As a result, tens or even hundreds of tons of metal may be reentering the atmosphere every year in the future, exceeding the amount of natural space rock that hits the planet.

The materials that satellites are made of are not naturally present in Earth's atmosphere, which means the consequences of such reentries can be unpredictable.

"Only 10 years ago, the reentries were not really a concern, because there were much more natural meteorites entering the atmosphere per year," Wilson said. "But if you have hundreds of thousands or millions of satellites in space at any one time, you are essentially going to create a rain of man-made materials, electronic equipment and metals that otherwise wouldn't be coming into the atmosphere."

He added that the situation is akin to ongoing climate change, which shows no signs of slowing down as humanity has so far failed to reduce carbon emissions.

"This is the most objects we've ever had in space, and we're continuing to propose more and more and more and more and more," Wilson said. "And there seems, in my opinion, to be very little consideration for the environment."

Not enough funding is currently flowing into research to answer the unknowns, Marais added.

"We need way more observations and way more time to be able to look into that," she said.

Boley concurred: "We absolutely have to understand, and we have to understand that before we actually launch a million satellites. Not that we launch them and wait [to see] what happens."

The plans of the satellite companies are stirring protests also among astronomers, who fear that the light pollution the constellations create will impact astronomical observations. A recent study by the European Southern Observatory concluded that, if all currently planned satellite constellation projects were to be built, astronomical research from the surface of Earth would no longer be possible.

A spectacular total solar eclipse will coincide with the peak of the Perseid meteor shower on Aug. 12-13. But will you be able to spot shooting stars in the false twilight of totality?

Perseids appear as Earth plows through the stream of debris shed by comet Swift-Tuttle. Up to 100 shooting stars may be seen each hour around its peak under ideal dark skies, as particles from the ancient comet collide with our atmosphere at speeds of 133,200 mph (214,365 km/h) to etch a fiery path through the summer night sky.

It's an unmissable highlight of the skywatching calendar, supercharged in 2026 by the spectacle of a total solar eclipse, which will plunge millions across Greenland, Iceland and Spain into the darkness of an eerie twilight, as the moon crosses the face of the sun.

Is it possible to see shooting stars during totality?

Yes. The most brilliant Perseid shooting stars can shine bright enough to be spotted in the brief twilight of totality. But it's all a question of timing.

"It would have to be a fireball that passed through the darkest portion of the sky," Robert Lunsford of the American Meteor Society told Space.com in an email. "The Perseids usually produce about one fireball per three hours at night. That's asking a lot for one of these bright meteors to appear during a 2-3 minute window. If anyone does see one, they had better go play the lottery asap!"

NASA Meteoroid Environments Office head Bill Cooke added his own word of caution, noting that the relatively bright sky during totality will likely hide all but the most brilliant Perseids from sight.

"Only Perseid fireballs will be visible," Cooke told Space.com in an email. "Given the brightness and duration of the eclipse, you might see one if you're extremely, extremely lucky. [The] most likely scenario is that you will see no meteors whatsoever."

The odds are definitely stacked against you. But you never know. A piece of comet Swift-Tuttle could've broken away at just the right time, at just the right point in its orbit to meet a fiery end in Earth's atmosphere, just as the sun slips from view. As for our advice? Keep your eyes locked firmly on the eclipse as it unfolds in the skies above you. There'll be plenty of time for hunting Perseids later.

Want to capture gorgeous photos of the Aug. 12 cosmic doubleheader? Then be sure to read our expert guides to imaging a total solar eclipse, along with tips on photographing fast-moving meteors. You can also stay up to date with all the latest news and reports for the field with our total solar eclipse live blog!

Editor's Note: If you would like to share your astrophotography with Space.com's readers, then please send your photo(s), comments, and your name and location to spacephotos@space.com.

The Aug. 12 total solar eclipse is just one day away! Here's how you can watch the entire show live online from the comfort of your home

Millions of people across Spain, Iceland and Greenland will see the moon completely hide the sun during the climactic phase of totality on Aug. 12. Countless more skywatchers across Europe will witness a deep partial solar eclipse, as the moon's curved silhouette covers a swathe of the sun's surface, while failing to cover it entirely.

Thankfully, we live in modern times. So there's no need for you to miss out on the solar spectacle if you find yourself outside of the path of totality, or if clouds conspire to ruin your view. Here's where to watch every phase of the 2026 total solar eclipse live online.

NASA

NASA will be hosting its own livestream of the event starting at 1:15 p.m. EDT on Aug. 12, featuring live views of totality from cameras spread throughout the path of the eclipse. The visuals will be accompanied by information on the science of the incredible event and details on how the agency is working to learn more about our sun.

The NASA coverage will be hosted here on Space.com, but can also be streamed through YouTube, Twitch, NASA+, Facebook, Instagram and Amazon Prime.

Time and Date

Time and Date's YouTube livestream kicks off at 12 p.m. EDT (1700 GMT) on Aug. 12, bringing live views of the eclipse from Leon in northwestern Spain and the island of Mallorca, along with live commentary from journalist Anne Buckle and astrophysicist Graham Jones.

The European Space Agency

An official European Space Agency (ESA) livestream will begin at 1:30 p.m. EDT (1730 GMT) on Aug. 12. The stream will feature expert commentary on the science of the eclipse along with live views from telescopes at the Observatorio Astrofisco de Javalambre, which is located close to the Spanish city of Teruel directly in the path of totality.

Royal Observatory Greenwich

London's historic Royal Observatory Greenwich will host two simultaneous YouTube streams featuring live views of the partial solar eclipse starting at 1:15 p.m EDT (1815 GMT) on Aug. 12. The first livestream will be presented by Royal Observatory astronomer Greg Brown, who will discuss the science of the sun while providing expert commentary on the eclipse, while the second will offer a silent livestream, featuring visuals of the eclipse with no accompanying audio.

The Virtual Telescope Project

The Virtual Telescope Project livestream begins at 1:20 p.m. EDT (1720 GMT) on Aug. 12, bringing real-time views from the organization's robotic telescopes in Manciano, Italy, where a partial eclipse will be visible and from the path of totality in Spain. The Virtual Telescope Project will host a separate livestream a few hours later featuring views of the Perseid meteor shower peak, which occurs overnight on Aug. 12-13.

Be sure to check out our live blog for all of the latest news on the Aug. 12 total solar eclipse. We'll also have reports from Skywatching Writer Anthony Wood as he watches the eclipse unfold low in the horizon in central Spain, and also from Skywatching Editor Daisy Dobrijevic as she witnesses the spectacle during a voyage with HX Expeditions to Greenland!

Editor's Note: If you would like to share your eclipse photos with Space.com's readers, then please send your photo(s), comments, and your name and location to spacephotos@space.com.

Rocket Lab plans to start launching even more frequently and flexibly, thanks to a new portable spaceport system called "GHOST."

GHOST — short for "Global Hypersonic & Orbital Spaceport Technology" — turns the company's "Electron and HASTE rockets into a launch-anywhere, launch-anytime capability for multi-launch flight campaigns and critical national security missions," Rocket Lab representatives said in a statement today (Aug. 10).

"Packaged entirely within standard shipping containers, GHOST deploys complete rockets, launch infrastructure, ground support and range control systems anywhere in the world," they added.

Electron is Rocket Lab's workhorse orbital rocket, giving small satellites dedicated rides to the final frontier. The expendable 59-foot-tall (18-meter-tall) launcher debuted with a test flight in 2017 and has 83 missions under its belt to date.

As its full name suggests, HASTE ("Hypersonic Accelerator Suborbital Test Electron") is a suborbital version of Electron that customers use to test various technologies in the hypersonic flight environment. HASTE first flew in June 2023 and has flown nine times to date, most recently in June of this year.

Rocket Lab currently flies from two different launch sites — one on the North Island of company founder and CEO Peter Beck's native New Zealand and one at Wallops Island in Virginia. But the company recently announced plans to fly out of Alaska's Pacific Spaceport Complex as well, and GHOST will expand its launch footprint even further.

"Electron and HASTE revolutionized small orbital launch and hypersonic testing. Now we're making it easier to deploy them wherever they're needed most, whether that's for missile defense testing or sovereign orbital launch capability," Beck said this afternoon during Rocket Lab's second-quarter 2026 earnings call.

"We've mastered the art of building launch sites," he added. "Now we're making them deployable worldwide."

Rocket Lab intends to deploy its two planned pads at the Pacific Spaceport Complex using GHOST, Beck said during the call. The company was inspired to develop the portable spaceport system, he added, to meet the needs of a HASTE customer, who expressed a desire for Rocket Lab to be "a little bit more mobile than we are."

Rocket Lab currently flies out of two pads at its New Zealand site and one at Wallops, though it has built a second pad at the Virginia facility to accommodate launches of its coming Neutron rocket.

Neutron will be bigger and more powerful than Electron, and partially reusable as well; its first stage is designed to come back to Earth for recovery and reflight, like SpaceX's Falcon 9.

Rocket Lab originally wanted to fly Neutron for the first time in 2024, but the new launcher has yet to leave the ground. Such delays aren't uncommon in the case of new rockets, and the company is making considerable progress with Neutron, according to Beck.

"Every part of the vehicle has now seen significant testing," he said during today's call. "As with any complex development program, we've had to tweak a few things along the way, but we're moving now into final checkout and assembly of all of our flight hardware before integrating them at the pad."

The company is on target to deliver the first Neutron to that Wallops pad in the fourth quarter of this year, Beck added.

Thanks to the Hubble Space Telescope, astronomers have shed light on a recent chapter in the history of our Milky Way's neighboring galaxy, Andromeda.

Using Hubble Space Telescope observations of Andromeda's stars, a research team showed that the spiral galaxy's rate of making new stars has dramatically slowed down in the last 40 million years. And they've found more evidence that one of Andromeda's own neighbors — a smaller galaxy called M32 — may be to blame.

"We can't explicitly say that we are seeing a decrease in star formation because of M32. But it's right there, and it's definitely the most likely suspect," said Tobin Wainer, a graduate student at the University of Washington and one of the astronomers, in a statement.

Astronomers like Wainer knew from prior research that Andromeda saw a burst of star formation about 2 billion years ago (possibly as a result of a collision with an unknown galaxy). They also knew that star formation had slowed down since then. What they did not know was how quickly that deceleration had been. If they could find out, they could fill in some of the gaps in Andromeda's history.

At 2.5 million light-years' distance, Andromeda is near enough to Earth that Hubble can measure its stars. In the past several years, Hubble has conducted two surveys of Andromeda. While Hubble can only make out stars in Andromeda that are brighter than our sun, these two surveys still gave Wainer and colleagues a compendium of 200 million stars, covering two-thirds of Andromeda's disk.

Wainer and colleagues parceled out this vast space into a grid of squares, 300 light-years to a side. They reconstructed the history of each square by examining the colors of its stars.

A square with many bright blue stars, for example, probably saw a lot of star formation recently, since blue stars tend to be younger. On the other hand, if a square only contains smaller, redder stars, we know those stars are longer-lived and older, and that square probably hasn't seen a lot of newborn stars.

The astronomers mapped out a story of slowing star formation. Around 500 million years ago, on average, Andromeda turned the equivalent of our sun's mass in gas and dust into newborn stars each year. As millions of years passed, that rate declined. About 40 million years ago, it was about one-half the sun's mass each year. Then, it tilted into a dramatic deceleration. Today, it stands at about one-fifth the sun's mass each year.

Curiously, they found that Andromeda's starmaking slowdown is especially pronounced on one particular side of the galaxy, starting about 60 million years ago. Astronomers know this side of Andromeda is closest to another galaxy: M32.

Astronomers have eyed M32 with suspicion for some time now. M32 is only located about 16,000 light-years from Andromeda (Andromeda is formally called M31) and it looks like the rump core of a spiral galaxy that lost its arms. It's possible that this is actually the aftermath of a collision between M32 and its larger neighbor. It's possible, though not confirmed, that Andromeda's slowing bears the fingerprints of this collision.

We may not need to wait long for more answers. Just as Hubble can see Andromeda's stars, so too will the Nancy Grace Roman Space Telescope, set to launch in late August. In the coming years, Roman will be able to measure even more of Andromeda than Hubble has.

Given how much I enjoyed the Project Hail Mary movie, I was beyond hyped to get my hands on the Lego Project Hail Mary set. And now that I've built it, I'm thrilled to say it does not disappoint. You could even say that it's amaze, amaze, amaze!

The titular Hail Mary is the spaceship from "Project Hail Mary", the Andy Weir novel-turned-Hollywood blockbuster that carries Ryland Grace (Ryan Gosling) across the stars to save humanity. While the design of the ship is certainly described in the book, this is definitely a Lego rendition of the movie version. So, if you're an Andy Weir fan who imagined it looking a little different, you can blame the studio.

Coming in at $99.99 with just under 900 pieces, it's a lot smaller than we expected (and hoped for). If you're after something comparable to the hefty NASA Artemis Space Launch System or gargantuan Venator-Class Republic Attack Cruiser sets, then you'll be disappointed. However, the Lego Project Hail Mary has a heck of a party trick to make up for its diminutive size: A spinning mechanism that simulates the centrifugal gravity system of the ship.

Lego Project Hail Mary review: Build

The Lego Project Hail Mary is constructed from 830 pieces, split across six numbered paper bags, with a few large pieces in a separate plastic bag. I built the kit over the course of two nights, but you could easily smash it out in a single evening if you wanted to.

The build starts with a little diorama, showcasing the Ryland and Rocky minifigures on either side of a window (the barrier that separates them when they first meet and learn to communicate in the movie). It's a cool little display that can work well on its own or can be attached to the stand of the ship itself.

From there on, four out of the six bags are almost entirely dedicated to the display stand and the incorporated spinning mechanism, with the final section of bag four attaching the ship’s crew module to the spinning mechanism. Thanks to the intricate mechanism inside it, the stand not only spins, but also retracts and extends the crew section of the ship, simulating the centrifugal gravity system from the movie. While it's a complicated mechanism that means a lot of Technic pieces, but the build itself is straightforward thanks to the clear instructions.

At last, the final two bags will see you constructing the ship itself. This consists of the main body where the thruster is housed, the three fuselage sections, and the solar panel array that provides power to the ship. Some builders might be disappointed that the actual spacecraft is a remarkably small part of the build process, but I think the spinning display stand is cool enough to offset that. Also, there are no stickers, which is always a huge win for me.

Lego Project Hail Mary review: Design

As I mentioned earlier, the display stand is surprisingly hefty and draws the eye away from the beautiful ship – a bit more than you might want from a display piece. That's the downside, but the upside is that it's an awesome party piece. Turning the handle on the front of the stand in either direction rotates the entire ship, simulating its spin in the movie. If you turn the handle clockwise, the crew module extends outward, while turning it counterclockwise retracts it.

The ship itself is a great recreation of Grace's eponymous craft, the Hail Mary. It's quite small, as Lego spaceships go, so there are no interior details or easter eggs hiding within the construction. Despite that, it captures the distinctive silhouette of the craft well, and includes all the major details, like the astrophage-powered engines that make the whole mission possible. From the three main pillars of the ship, which are the fuel tanks that store the astrophage, to the solar panel arrays that stick out from the main body, it all looks great.

I really love the little mini-diorama scene that you can create between Grace and Rocky, recreating their tentative first contact. It's a clever bit of design too, as you can attach their individual plinths to the main display and tuck the glass divider away in the stand. The minifigures themselves are great too. Grace has a custom red NASA flight suit, while Rocky is barely a minifigure — he's an eccentric collection of pieces mashed together, but I can't deny the end result is unmistakable Rocky.

Should you buy the Lego Project Hail Mary?

Overall, the Lego Project Hail Mary is a wonderful set that should thrill fans of the movie (more so than fans of the book, although I’m sure they’ll enjoy it too). The ship looks fantastic, and the spinning mechanism is wonderful to see in motion. There are actually some enterprising companies out there selling motorized mod kits for it, which is something I'm seriously considering checking out myself.

With that said, the prominent nature of the stand and somewhat gimmicky spinning feature does limit its appeal as a display model. Plus, those who aren’t big into technic-like builds may want to pass on this one and just admire it from afar.

Finally, while the build itself is only suitable for older teens and adults due to the complex nature of the internal workings, the finished model will definitely delight younger kids thanks to the interactivity it offers.

China's latest rocket launch ended in failure this morning, lighting up the skies with some unwanted fireworks.

The state-owned China Aerospace Science and Technology Corporation (CASC) launched a Long March 7A rocket today (Aug. 10) from the Wenchang Space Launch Site, in the country's Hainan province, just after 8:00 a.m. EDT (1200 GMT; 8:02 p.m. local time). Around 85 seconds into the launch, the rocket exploded, generating a massive fireball and a cloud of smoke and debris while still soaring through Earth's atmosphere.

CASC had not yet released a statement about the incident by the time of this story's publication, but video reposted to social media captured the shock of onlookers the moment that the rocket burst into flames. Based on such views, the mission will almost certainly be deemed a complete failure, with total loss of vehicle and payload.

Today's launch was the 18th Long March 7A mission since the rocket's debut in 2020, which, subsequently, also ended with the vehicle's explosion. China traced that mishap to an engine malfunction that occurred shortly after first-stage separation. This morning's launch, however, didn't get that far.

The Long March 7A's four side boosters and core stage detach as a full cluster during first stage separation, which typically occurs just under three minutes after liftoff. As today's incident occurred just 85 seconds into flight, the rocket was still engaged in the main stage's initial engine burn to escape Earth's atmosphere.

The 7A — a variant of China's Long March 7 rocket family — stands just over 197 feet (60 meters) tall and combines the first two Long March 7 stages with a hydrolox (liquid hydrogen and liquid oxygen)-powered third stage capable of launching up to 7 tons to geostationary transfer orbit (GTO).

According to China National Radio, today's launch carried China's Zhongxing-4B spacecraft,, a communications satellite presumably bound for GTO. China's Zhongxing satellites provide telecommunications and broadband internet services and are also thought to provide services for China's military.

It is unclear what repercussions today's explosion may have on upcoming launches, including a Chinese Zhuque-3 rocket liftoff scheduled for Monday evening. That mission is scheduled to fly from China's Jiuquan Satellite Launch Center, more than 1,500 miles (2,415 kilometers) from Wenchang, at 7:45 p.m. EDT (2345 GMT; 7:45 a.m. local time), and is expected to feature a first-stage landing attempt.

CASC uses the standard Long March 7 rocket, which shares its core stage with the 7A, as its launch vehicle for delivering cargo to the Tiangong space station in low Earth orbit about every eight months. The most recent of those missions launched in May, putting the next resupply launch sometime around January 2027. Depending on the cause of this morning's explosion, that mission and others could face delays as China investigates the incident.

Editor's note: This story was updated at 4:20 p.m. ET on Aug. 10 with new photos of the launch.

Originally launched a decade ago, the ZWO ASI174MM is a planetary astrophotography camera — something you insert into the eyepiece of a telescope to take images and video of deep-sky objects, planets, the moon and the sun. This one is very much geared towards the latter, with solar and lunar imaging its goal.

At first glance, the specification looks simple: a 2.3MP monochrome Sony IMX174 sensor, 5.86µm pixels, USB 3.0 connectivity and a compact red aluminum body. The important details are the sensor size, speed and global shutter. For lunar and solar imaging, where you often want to capture large areas in high frame rate videos and freeze split-seconds of steady “seeing” — when turbulence in Earth’s atmosphere doesn’t degrade an image of an astronomical object — those traits matter more than headline megapixels.

The ASI174MM is especially attractive for solar imaging with an H-alpha telescope — a filter that blocks all wavelengths of light other than H-alpha, which is emitted by hydrogen atoms. That’s because its 5.86 μm pixels match the focal ratios typical of solar telescopes, yielding sharp, efficient detail. Its relatively large sensor can cover more of the solar disc than many small planetary cameras, while its high frame rate supports the usual lucky-imaging workflow of capturing video, selecting the best frames and stacking them for sharper images.

ZWO ASI174MM astronomy camera: Design

• Compact aluminum camera body
• USB 3.0 and ST4 guide port included
• Useful adapter bundle

The ZWO ASI174MM has a compact, lightweight and practical design that’s ideal for use as a camera attached to a telescope. Its small cylindrical aluminum body adds very little strain to a focuser, solar diagonal or off-axis guider, which is particularly useful when working with solar telescopes.

Usefully, the camera includes a high-speed USB 3.0 connection, which is important because the ASI174MM’s main strength is capturing and transferring many video frames very quickly. It can also be used over USB 2.0, but doing so gives up much of the performance that makes the camera appealing in the first place.

An ST4 guide port adds extra flexibility. Although the ASI174MM is primarily sold as a planetary camera, it can also be used as a guide camera (mounted on top of a main imaging scope to capture a wide field of view), especially with off-axis guiders (a device that sits between a main camera and the telescope to precisely track stars), where the larger sensor helps find guide stars more easily than smaller-chip models.

ZWO ASI174MM astronomy camera: Performance

• Excellent for solar and lunar video capture
• Global shutter is a real advantage
• Large pixels favor longer focal lengths

The ASI174MM’s combination of a relatively large 1/1.2-inch sensor, 5.86µm pixels, and fast video capture makes it particularly well-suited to imaging the sun and moon. Compared with planetary cameras built around smaller sensors, it records a considerably larger area of the telescope’s field of view, reducing the number of panels needed for mosaics and making it easier to locate and frame a target.

That larger sensor is especially useful for solar imaging, which is what we tested it with. The exact field of view depends on the telescope’s focal length, but the ASI174MM can capture larger active regions — and, with some setups, most or all of the solar disc — without immediately requiring a mosaic. For example, we tested it with the Sky-Watcher Heliostar 76Ha solar telescope, for which it is a natural match, where prominences, filaments, sunspots and rapidly changing structures on the solar surface need to be recorded at high speed.

The camera’s global shutter is another advantage for solar imagers. A rolling shutter (the standard choice for deep-sky imaging) records an image progressively, one row of pixels at a time, to produce a low-noise, high-dynamic-range image. However, atmospheric turbulence, which slightly shifts the image, can cause distortion. A global shutter exposes the entire sensor simultaneously, helping the ASI174MM preserve the shape of solar and lunar features more accurately from frame to frame.

High-speed capture also supports lucky imaging. Instead of trying to produce one perfect exposure, the camera records thousands of short exposures in rapid succession. Software then identifies and stacks the sharpest frames — the brief instants when Earth’s turbulent atmosphere becomes relatively steady.

While it’s ideal for solar imaging, the ASI174MM is much less convincing as a conventional deep-sky camera. Long exposures can reveal pronounced amp glow towards one side of the frame, while the uncooled sensor becomes increasingly noisy as exposure times increase. Calibration with dark frames can reduce these effects, but it adds complexity and cannot turn the ASI174MM into a modern cooled deep-sky camera. It can be used for short-exposure imaging, guiding and some specialist applications, but solar, lunar and planetary video remain its natural strengths.

ZWO ASI174MM astronomy camera: Functionality

• Captures good data
• ZWO software works well
• Little guidance available

The ASI174MM fits neatly into the established workflow for solar, lunar and planetary imaging: capture a high-speed video, identify the sharpest frames, align and stack them, then sharpen and process the image. Its fast USB 3.0 connection enables high data transfer rates, while region-of-interest controls allow the user to record only a selected portion of the sensor. Reducing the size of the recorded area can substantially increase the frame rate, which is particularly useful when imaging an individual sunspot.

Several free applications can control the camera and record these videos, including SharpCap and FireCapture. AutoStakkert! is widely used to analyze, align and stack solar, lunar and planetary frames, while programs such as ImPPG, RegiStax, Siril, Adobe Photoshop and GIMP can be used for sharpening, contrast adjustment and final processing. Windows users have the widest choice of third-party astronomy software.

However, ZWO also provides its own free ASIStudio software suite. For the ASI174MM, the most relevant applications are ASICap, which controls the camera and records lossless SER or AVI video, and ASIVideoStack, which analyses and stacks the resulting frames (and can also be used for post-processing). ASIStudio is available for both Windows and macOS.

The basic capture process is straightforward. After connecting the ASI174MM to ASICap, exposure time and gain are adjusted until the brightest areas of the sun or moon remain below saturation. Because this is a monochrome camera, the live view can be shown either in grayscale or with false color applied for easier viewing. A video containing around 1,000 to 3,000 frames is then recorded, though the ideal number depends on the target, seeing conditions and available storage.

Storage requirements are significant. Uncompressed high-frame-rate video from the full sensor can consume several gigabytes in a matter of seconds, so a fast computer, a USB 3.0 connection and plenty of free drive space are essential.

Once a video is loaded into ASIVideoStack, the software can assess frame quality, align the image and combine a chosen percentage of the sharpest frames. The finished stack can be exported in formats including JPEG and FITS. JPEG is convenient for immediate sharing, but FITS preserves more of the original image data and is better suited to serious post-processing.

The workflow is functional rather than polished. There is relatively little guidance for beginners and obtaining the best results requires experimentation with exposure, gain, frame rate, focus, stacking percentages and sharpening settings. It can take many attempts to determine which combination works best with a particular telescope and observing conditions. For that reason, it’s wise to archive the video files, which can be revisited and processed later as processing skills/software improves.

How we tested the ZWO ASI174MM

We tested the ZWO ASI174MM planetary camera for two weeks and used it in conjunction with the Skywatcher HelioStar 76mm solar telescope and Solar Quest mount to image the sun in H-Alpha (Hα).

Should I buy the ZWO ASI174MM?

Buy the ZWO ASI174MM if your main targets are the sun and moon, especially if you want a monochrome camera with a larger-than-average sensor, fast frame rates and a global shutter. It remains particularly suited for H-alpha solar imaging, where monochrome capture, speed and sensor area matter.

If this product isn’t for you

If you want a cheaper first planetary camera, a smaller-sensor ZWO ASI120-series-style camera may be enough for basic lunar, planetary and guiding use, though it will not offer the same field of view.

If you want a more modern planetary camera, look at newer monochrome planetary models like the ZWO ASI585MM with lower read noise, smaller pixels or higher resolution, depending on your telescope’s focal length.

If your goal is deep-sky imaging, a cooled astronomy camera is a better choice than the ASI174MM. We have reviewed the ZWO ASI533MC Pro and the ASI183MC Pro and gave both of them nothing less than four and a half stars for beautiful deep-sky astrophotography.

Scientists have captured the sharpest image ever of our sun's surface. This view has revealed incredible new details about the inner mechanisms driving stellar activity.

What is it?

An international team of researchers using the U.S. National Science Foundation's Inouye Solar Telescope has captured the highest-resolution view of the sun's surface.

In analyzing observations from this telescope, the team, made up of researchers from the National Solar Observatory, the NSF NCR High Altitude Observatory and the German Max Planck Institut für Sonnensystemforschung, discovered strange patterns on the sun's surface. The whirling patterns, they found, are actually evidence of what's called Kelvin-Helmholtz instability (KHI), or instability that happens when there is a change in velocity of fluids.

Why is it incredible?

This image is groundbreaking. Capturing the highest-resolution view of the sun's surface is a massive accomplishment, and in the time-lapse video above, you can even see the fluid dynamics on the surface of the sun in motion.

But this view is much more than a beautiful, high-resolution image. These observations have revealed swirls on the sun's surface at the edges of the magnetic areas, allowing the team to identify KHI on the sun's surface. This fluid instability has long been suspected on the sun, but these observations are the first time they have ever been directly seen like this.

“We believe that the discovery of Kelvin-Helmholtz Instability in the solar photosphere, backed up by analysis of numerical simulations, is a major step forward in our understanding of the dynamics and evolution of solar and stellar plasma, and will serve as a basis for future discoveries," David Boboltz, the deputy director at the National Solar Observatory, said in a statement.

A paper describing these findings was published recently in the journal Nature.

On Aug. 10, 1972, an Earth-grazing fireball burst through the sky over North America. It didn't hit the ground, but instead it passed straight through the sky.

The fireball entered the atmosphere somewhere over Utah and passed northwards, leaving the atmosphere over Alberta, Canada about 100 seconds later.

Analysis of its trajectory showed the object was about 10 to 45 feet in diameter, depending on whether it was an icy comet or a denser, rocky asteroid.

Why it mattered

When we think of fireballs, we typically think of "shooting stars" during a meteor shower: a night sky spectacle that's brief but brilliant. But a daytime fireball is something else altogether.

Nighttime meteors are typically tiny particles of space dust or rocks that burn up as they streak through Earth's atmosphere. While they look impressive in the night sky, they're relatively dim. City streetlights or even a bright full moon can outshine them.

But a daytime fireball is caused by something large enough to be visible in the sky in broad daylight, something large and fast enought to light up a sky brighter than a sunlit day. That's what happened today in 1972.

Today, an event like the "Great Daylight Fireball" of 1972 (as it came to be named) would be visible to potentially millions of witnesses as it streaked over the United States and Canada, and we'd likely see social media flooded with images and video. There is at least one reported video of the 1972 event you YouTube, but nothing compared to what we'd see if it happened today.

Japan's H3 rocket flew for the ninth time ever this afternoon (Aug. 10).

The H3 lifted off from Tanegashima Space Center today at 3:23 p.m. EDT (1923 GMT; 4:23 a.m. on Aug. 11 local time), carrying the Michibiki 7 navigation satellite aloft.

The H3's upper stage deployed Michibiki 7 into its target orbit 29 minutes later, eliciting cheers from the folks in mission control.

The two-stage H3 is the successor to Japan's workhorse H-2A rocket, which retired last year after a total of 50 flights.

The H3 — which stands 187 feet or 207 feet (57 or 63 meters) tall, depending on what type of payload fairing it employs — debuted in March 2023 and had eight liftoffs under its belt before today.

Two of those eight were failures — the debut flight and the launch of Michibiki 5 in December of last year. But the H3 bounced back from that latter anomaly two months ago, successfully delivering six satellites to orbit on June 11.

Michibiki 7 will be part of Japan's Quasi-Zenith Satellite System (QZSS), a homegrown navigation system that operates high above Earth in geosynchronous orbit.

"This system is compatible with GPS satellites and can be utilized with them in an integrated fashion," Japanese officials wrote in a description of the QZSS project. "QZSS can be used even in the Asia-Oceania regions with longitudes close to Japan, so its usage will be expanded to other countries in these regions as well."

The QZSS network will eventually consist of 11 satellites, if all goes according to plan. There are five such spacecraft operating in orbit at the moment.

Michibiki 7 is carrying a payload for the United States as well — the Situational Awareness Camera Hosted Instrument (SÃCHI), which was developed for the U.S. Space Force by the MIT Lincoln Laboratory. This is the second of two SACHIs to go up on a QZSS satellite; Michibiki 6, which launched atop an H3 in February 2025, hosts the other one. (Yes, Michibiki 6 launched before Michibiki 5.)

"This program will allow the United States to monitor satellite behavior within the GEO belt over a very interesting part of the world," Mark Huber, a technical staff member in the Lincoln Laboratory's Space Systems and Technology Division, said in a statement in December 2020.

"It is also a pathfinder in several ways," he added. "The U.S. team is blueprinting methods to allow sensitive data sharing between the United States and Japan."

Editor's note: This story was updated at 3:55 p.m. ET on Aug. 10 with news of successful launch and satellite deployment.

Pluto's atmosphere appears to be freezing out as the dwarf planet moves ever further away from the sun, according to careful observations of Pluto astronomers made as it was seen passing in front of stars in the sky.

Pluto is already cold. Its surface temperature is about –382 degrees Fahrenheit (–230 degrees Celsius), while its upper atmosphere is a little warmer at –333 degrees Fahrenheit (–203 degrees Celsius). As Pluto moves away from the sun it will grow even colder and its nitrogen-rich atmosphere should start to collapse and freeze out, condensing as frost on the frigid surface.

Now, a team led by Amanda Sickafoose of Arizona's Planetary Science Institute believe they have seen the onset of this process. "We're at a particularly interesting point for Pluto," said Sickafoose in a statement. "Our work suggests that the atmosphere has recently started decreasing in pressure."

Pluto's orbit is highly elliptical and very oblique to the ecliptic plane of the solar system. In fact, so eccentric is Pluto's orbit that for ten years either side of its perihelion in 1989 (when Pluto was closest to the sun), it was actually closer to the sun than Neptune was.

However, ever since 1989 Pluto has been moving away from the sun on its 248-year-long orbit – we've not even seen Pluto complete half of its orbit yet since its discovery in 1930. Pluto will reach its furthest point from the sun – called aphelion – in the year 2114 when it will be about 49 astronomical units (7.3 billion kilometers/4.6 billion miles) distant.

When NASA's New Horizons mission flew past Pluto in July 2015, it measured Pluto's atmospheric pressure to be 10 microbars. This is a tiny amount, millions of times lower than the atmospheric pressure on Earth, resulting from Pluto's thin nitrogen atmosphere that also contains hazes made from organic molecules including methane and carbon monoxide.

With New Horizons now having flown past Pluto and deeper into the Kuiper Belt, astronomers have to instead rely on more distant and less direct means of keeping tabs on Pluto's atmosphere. From our point of view on Earth, Pluto is sometimes seen to pass in front of a distant star. This is called a stellar occultation. When an airless body, such as an asteroid, occults (or hides) a background star the star's light winks out in an instant, before suddenly reappearing. When there is an atmosphere involved, however, the light of the star doesn't go out all at once when blocked by Pluto, but steadily fades as the atmosphere scatters and refracts the starlight before the star vanishes behind the dwarf planet's solid body.

Between 2017 and 2023, Sickafoose's team probed Pluto's atmosphere during ten occultations of stars ranging in brightness from about magnitude 12 to magnitude 18, far below naked-eye visibility.

Observing stellar occultations is not always a simple matter. They are not visible from everywhere on Earth, but only along narrow tracks, often in difficult to reach areas. The tracks, which are just a few kilometers wide, are effectively Pluto's shadow falling on the Earth. By spacing observers across the width of the track, it is possible to measure the extent of Pluto's atmosphere (there usually also has to be an unlucky observer just outside the track to confirm that is indeed the edge of the shadow track).

"I'm constantly amazed at how the simple technique of watching starlight dim and reappear allows us to study a thin atmosphere – a few millionths of the Earth's – on a world two-thirds the size of our moon and 30 times farther from the sun," said Sickafoose.

Of the ten occultations, four could be seen from observatories in multiple locations, which meant that the different observatories could confirm each other's results.

"We often prefer to observe predicted occultations that have shadow paths over large observatories because that equipment and data have proven successful," said Sickafoose. "Then, we try to improve those datasets by collaborating with local observers in the shadow paths."

Previous work had suggested that Pluto's atmosphere began freezing out in 2018, but Sickafoose's team found that actually, Pluto's atmosphere remained constant from 2015 to midway through 2021. However, between mid-2021 and the last occultation that Sickafoose's team observed in 2023, Pluto's atmospheric pressure dropped by 16 per cent.

The pressure drop was deduced from the light curves, which show how the star's brightness changed with time during an occultation. The light curves revealed that while the structure of Pluto's upper atmosphere remained fixed, the lower atmosphere changed.

Sickafoose's team interprets this as being the haze particles settling towards lower latitudes. This is what is expected to happen when the atmospheric pressure drops.

"I am hopeful that we'll be able to get more data in the next years to decades to specifically confirm or refute this trend," said Sickafoose.

It is thought that Pluto's atmosphere won't have completely frozen onto the dwarf planet's surface by the time it reaches aphelion, and then as Pluto begins moving in towards the sun once more the feeble solar heating that Pluto receives will slowly begin to increase, causing nitrogen frost to sublimate from the surface and thicken the atmosphere once more.

The findings were published on July 31 in the Planetary Science Journal.

On Aug. 12, 2026, a total solar eclipse will sweep across Earth, giving skywatchers across Greenland, Iceland and northern Spain an incredible view of totality. As the moon completely covers the sun, day will briefly turn to twilight, revealing the sun's faint outer atmosphere, the corona. But could totality reveal something else too?

Although totality never produces true nighttime darkness, it does briefly dim the sky to roughly the brightness of twilight. Since eclipse chasers in Greenland and Iceland will be in the auroral zone — the geographic zone around Earth's magnetic pole where auroras are most frequently seen — it's natural to wonder whether the two phenomena could appear together.

The answer is yes — but only if everything falls perfectly into place.

"During totality, the sky brightness is comparable to civil twilight (the first period of darkness after sunset, until the sun reaches six degrees below the observer's horizon). It's uncommon to see auroras during this time, but by no means impossible," Tom Kerss, independent astronomer and Chief Aurora Chaser for tour company Hurtigruten, told Space.com in an email.

Kerss knows this from experience. Last year, he photographed the northern lights in Norway at twilight, demonstrating that sufficiently bright auroras can remain visible even before the sky becomes fully dark.

However, the aurora's position in the sky would impact its visibility.

"During totality in August, the surface brightness of the sun's corona would almost certainly outshine auroras in its vicinity, but other parts of the sky away from the eclipse could host visible auroral structures," said Kerss.

So while it's physically possible, how likely is it?

Not very.

"If the auroral activity stays quiet, we wouldn't expect to see it during totality even though we know some energy is probably being emitted in the dayside portion of the oval," Kerss said.

To have any realistic chance of seeing the northern lights during the eclipse, Earth would need to be in the grip of a severe geomagnetic storm. These storms occur when eruptions from the sun, such as coronal mass ejections (CMEs), slam into Earth's magnetic field. During such conditions, auroras can get a dramatic boost, appearing brighter and more widespread than usual.

Kerss explained that observers would almost certainly need a G4 or G5 geomagnetic storm (G5 is the most powerful category) to overlap with the eclipse to have any realistic chance of seeing an aurora show because they will be on Earth's dayside.

"Bright, nightside aurora can be driven by powerful substorm activity, in which energy is stored and released," Kerss explained. "The dayside aurora is driven by a combination of favorably aligned solar wind (which opens the field lines around the Earth's polar cusps) and strong precipitation directly into the auroral oval. This latter requirement is contingent on very strong or extreme geomagnetic activity."

Kerss' thoughts are echoed by Pål Brekke, a solar physicist and northern lights expert working as Lead of Space Science at the Norwegian Space Agency.

Brekke knows just how difficult this is. He attempted to spot auroras during the 2015 total solar eclipse over Svalbard but found the sky never got dark enough.

"The sky never got that dark — we could hardly see any planets and no stars," Brekke told Space.com in an email. "Most probably because the snow-covered valley and mountains reflecting lights leaking in from the side of the moon's shadow. Making the sky too bright even during the eclipse."

Brekke also pointed out that the timings work against eclipse chasers. Totality occurs in the afternoon over Greenland and Iceland, meaning observers will be beneath the daytime portion of the auroral oval. Unlike the nighttime aurora oval, which expands dramatically during geomagnetic storms, the dayside auroral oval changes much less, making displays harder to see even during active space weather.

"The chance for aurora over Spain is very low — that would need a KP=9 or so — and 20:00 [UTC] is still very early so the fattest part of the oval is still not over Spain at that time. So our guess is it will not be very likely," said Brekke.

There is one scenario, however, that could make eclipse day even more extraordinary.

"If the sun launches CMEs in the days before the eclipse, it'll be very exciting for anyone going to Iceland or Greenland, and since the exceptional Perseid Meteor Shower will also peak on that date, there's a rare opportunity to see three of the sky's greatest wonders together if conditions line up," said Kerss.

The odds may be slim, but they're not zero.

If the sun happens to unleash a powerful geomagnetic storm in the days leading up to Aug. 12, eclipse chasers in Greenland or Iceland could witness something truly remarkable.

If not, don't be too disappointed. During totality, the sun itself puts on one of nature's greatest spectacles — and that's where your attention should be.

If you're planning to watch the total solar eclipse on Aug. 12, knowing exactly when to look up is crucial.

While totality will be visible from parts of Greenland, Iceland and Spain, millions more people across Europe will experience a dramatic partial solar eclipse. Whether you're chasing the moon's shadow in Reykjavik or watching the moon take a 'bite' out of the sun from London, Paris, or Berlin, timing is everything.

You can keep up with the latest total solar eclipse news and coverage with our total solar eclipse live blog.

Total solar eclipse timings

Partial solar eclipse timings for major cities

Looking for your own eclipse time? The interactive map and resources from Time and Date let you search by city and view detailed timing information for every stage of the eclipse.

What is a total solar eclipse?

A total solar eclipse occurs when the moon moves directly between Earth and the sun, completely blocking the sun's disk from view.

During totality, the sky darkens significantly, temperatures drop and bright stars and planets can even become visible. Observers can also catch a glimpse of the sun's outer atmosphere, known as the corona, glowing around the silhouetted moon.

Totality — when the sun is completely obscured — is only visible within the narrow path of the moon's shadow. Outside that path, observers may see a partial solar eclipse, whereby only a portion of the sun is covered.

REMEMBER to NEVER look directly at the sun. To view this solar eclipse safely, you must use solar filters. Only during the brief period of totality when the moon completely covers the sun, is it safe to look at the sun without protection. Observers will need to wear solar eclipse glasses, and cameras, telescopes and binoculars must have solar filters placed in front of their lenses at all other times.

Our how to observe the sun safely guide tells you everything you need to know about safe solar observations.

After this, when is the next solar eclipse?

After the total solar eclipse on Aug. 12, 2026, the next solar eclipse will be an annular solar eclipse on Feb. 6, 2027 visible across parts of Africa and South America. The next total solar eclipse will be a spectacular event on Aug. 2, 2027. Visible across North Africa, it will be the longest totality on land since 1991.

A new way to move around Earth's outer atmosphere could soon get a field test.

The Spanish company Kreios Space plans to launch into orbit the world's first satellite that uses scooped-up air to push it forward, the company announced on Tuesday (Aug. 4).

The technology Kreios Space has been developing is called air-breathing electric propulsion (ABEP). It relies on air sourced from Earth's atmosphere, which is then heated up, ionized and expelled to generate thrust.

This method will allow satellites in very low Earth orbit (VLEO) — the region from roughly 60 miles to 250 miles (100 to 400 kilometers) above our planet — to counteract atmospheric drag without the aid of liquid fuel.

"Kreios is building the satellites that make sustained operations in very low Earth orbit possible," Kreios Space CEO Adrián Senar said in the Aug. 4 announcement.

"By enabling satellites to fly lower, longer and more efficiently, we are enabling higher-resolution Earth observation, much better satellite communications, more responsive and accurate missions and a more sustainable orbital infrastructure," he continued.

Kreios Space chose Lithuanian-based Kongsberg NanoAvionics to provide the satellite bus that will carry the ABEP system into orbit for the test run.

"Kreios is tackling one of the most demanding operating environments in space, and this mission joins a very short list of European VLEO initiatives," Kongsberg NanoAvionics CEO Atle Wøllo said in the same statement.

"Our engineering team has worked closely with Kreios to configure the MP42 satellite bus to the mission's specific requirements and support the integration of Kreios' technology," he added.

Kreios Space did not give a target launch date for the mission in Tuesday's statement, saying that the company will launch it "at a time when interest in and development of VLEO technologies has accelerated." But the company's website identifies 2027 as a notional target for its first space mission.

A new, very low frontier

Satellites in low Earth orbit (LEO) — altitudes of roughly 100 miles to 1,200 miles (160 to 2,000 km) — generally don't need constant propulsion. Usually, a small boost from traditional thrusters here and there is enough to keep a LEO satellite on the right track. To power the thrusters, these satellites usually have some form of fuel built in.

VLEO works differently. It's low enough that there's still some atmosphere present, which generates drag on spacecraft. If you want a satellite to move around VLEO, it'll need to employ propulsion most or all of the time to counteract that drag. Any fuel that the satellite brings with it therefore won't last long.

So, if satellites are going to operate in VLEO, it would be very helpful to have a method of propulsion that doesn't require traditional fuel — a method like ABEP.

Satellites in VLEO have a few advantages over those operating in LEO, like sharper imagery thanks to the closer vantage point. One of the biggest advantages is that VLEO is much less crowded. There are thousands of satellites in LEO — most of them SpaceX's Starlink broadband spacecraft — and the number is growing all the time. But VLEO has plenty of room.

If ABEP technology works and companies start outfitting satellites with this new propulsion method, then we might start seeing satellites operate quite close to Earth, zooming through the atmosphere and using the air around it to stay on course.

On Aug. 9, 1976, the Soviet space program launched its last moon mission.

Luna 24 was a robotic sample return mission and the third of its kind. It lifted off on a Proton-K rocket from the Baikonur Cosmodrome in Kazakhstan and safely landed on the lunar surface nine days later.

The probe landed in a dark plain of the moon known as Mare Crisium, or the "Sea of Crises" and collected 6 ounces (170.1 grams) of soil samples, which it brought back to Earth on Aug. 22, 1976. Scientists then found that the samples from Luna 24 contained tiny traces of water — about 0.1% by mass.

Why it mattered

The Soviet Union lost the Space Race to land the first humans on the moon, but its Luna program of robotic probes was prolific. The country's Luna 2 was the first spacecraft ever to land on the moon (it slammed into the lunar surface in 1959), with the more advanced Luna 9 making the first-ever soft-landing on the moon in February 1966, beating NASA's Surveyor 1 by about 4 months.

By 1976, 12 NASA astronauts had walked on the moon, the last two on Apollo 17 in 1973 and the Space Race was over. But the Soviet moon program was not, with Luna probes and Lunakhod rovers.

• The 21 Most Marvelous Moon Missions of All Time

The Luna sample return missions consisted of a lander equipped with a descent stage, ascent stage and Earth return capsule. The probes could collect samples of the moon, place them in the return capsule on the ascent stage, then rocket it from the moon for the trip back to Earth. NASA's Lunar Reconnaissance Orbiter has captured photos of the descent stages of Luna 16, Luna 20 and Luna 24 still on the moon.

The Luna 23 spacecraft remained on the moon entirely, as it was damaged during landing and wasn't able to return a sample. NASA's LRO images later revealed Luna 23 likely fell on its side. But Luna 24, the last of the series, worked as planned, landing on Mare Crisium on Aug. 16, 1976, collecting a sample of the lunar regolith and launching back into space less than 24 hours later.

While Luna 24 was the last Soviet moon sample return mission, it was not the last for Russia.

In August 2023, Russia's Roscosmos space agency launched the Luna 25 mission, its first in 47 years, toward the lunar south pole.

Luna 25 was planned to be the first in a new fleet of moon probes, but ultimately crashed into the moon after an orbital maneuver went wrong.

Want more space history? Check out our full On This Day In Space Story archive and watch our On This Day In Space videos on YouTube.

Every total solar eclipse is different. While the silhouette of the moon passing across the sun barely changes, the moment our natural satellite covers the entire solar disk, something spectacular happens — the emergence of the corona. The Latin word for "crown", the solar corona is one of the wonders of nature. To gaze upon its delicate, spiky white tendrils during brief moments of totality is to glimpse the infinite, but it's only a glimpse because the corona is always changing. Shaped by the sun's constantly changing magnetic field, the corona evolves from year to year, month to month and even day to day. No two total eclipses ever reveal exactly the same structure.

It's one reason why eclipse chasers keep traveling. The corona visible during the total solar eclipse of Aug. 12, 2026 — if skies are clear — will be a unique snapshot of the sun at a specific moment in Solar Cycle 25. It will reflect years of changing magnetic activity, thousands of sunspots and countless eruptions of solar material.

Once totality ends, that exact configuration of the corona will never be seen again. Can we know in advance what it might look like?

The sun's hidden atmosphere

Under normal circumstances, the sun's corona — our star's outer atmosphere — is invisible. It extends millions of miles into the solar system, but it's overwhelmed by the brilliant light of the sun's photosphere, its visible surface. Totality changes that. When the moon completely covers the photosphere, the corona suddenly emerges. White streamers extend away from the black silhouette of the moon. Pink loops and prominences can appear around the edge of the moon.

For many first-time observers, the greatest surprise during totality is not only the detail but the scale. The corona often appears much larger than expected, extending several solar diameters away from the eclipsed sun. Photographs can capture some of that complexity, but they rarely reproduce the impression of depth and structure visible to the human eye, whose dynamic range is vastly superior to any camera.

Why every corona looks different

The corona is not a fixed object. It is created by extremely hot plasma — highly energized, ionized gas — that's trapped and sculpted by the sun's magnetic field. Since the sun's magnetic field is constantly changing, the corona changes with it.

"The sun follows a natural 11-year cycle of increasing and decreasing activity," Ryan French, solar physicist, author and science communicator at the Laboratory for Atmospheric and Space Physics (LASP) in Boulder, Colorado, and author of Little Book of Eclipses: An Essential Companion to Solar and Lunar Events told Space.com in an email. "At the peak of this cycle, called solar maximum, there are loads of sunspots on the sun, which are giant magnets nestled in the base of the sun's atmosphere. These sunspots produce a lot of solar flares and coronal mass ejections, which are kind of bursts and eruptions of energy from the sun's atmosphere, and at solar minimum, the sun has none of these things."

That magnetic activity determines the overall shape of the corona. During solar minimum, when the sun has few or no sunspots, the corona tends to look more uniform and more symmetrical. Long streamers often stretch from either side of the sun, giving the corona a wing-like appearance. During solar maximum, it can look much more complex. Sunspot regions act like magnetic anchors, creating structures that can appear as spikes or streamers extending in different directions.

"If you were to see a total eclipse during solar maximum, the solar corona looks almost like a five-pointed cartoon star," said French. "That's because every one of these sunspot regions creates a spire or spike that you can see with the eye."

Not solar maximum — but not quiet

The 2026 eclipse will not occur at solar maximum. Solar Cycle 25 peaked in October 2024, according to NASA and NOAA, with the Aug. 12, 2026 eclipse occurring almost two years later, during the cycle's declining phase. However, solar activity does not collapse immediately after solar maximum. It declines gradually, and the sun is expected to remain more active than it was in the lead-up to solar maximum.

"We're no longer in solar maximum — we're a third of the way past the peak in terms of amplitude and years passed," said French. "The corona will still be far more active than during the 2017, 2019 and 2020 total solar eclipses, but much less so than 2024's."

That makes the 2026 eclipse especially interesting. It likely won't show the full, highly structured corona seen close to the peak of activity in 2024, when the April 8 total solar eclipse occurred with a monthly sunspot number of about 144. Current predictions for August 2026 are closer to 102; far fewer, but still considered active by recent-cycle standards.

That means eclipse-watchers should expect something between extremes: not the clean, flattened corona of solar minimum, but not quite the wildest solar-maximum display either.

A comparison with past eclipses

A useful comparison may be the total solar eclipses near the previous solar maximum. Solar Cycle 24, which peaked in April 2014, was relatively weak. The closest total solar eclipses to that peak were the rare hybrid eclipse of Nov. 3, 2013, when the monthly sunspot number was around 113. By contrast, Solar Cycle 23, which had a double peak — in March 2000 and November 2001 — was relatively strong. The closest total solar eclipse occurred on June 21, 2001, with a monthly sunspot number of around 203. Its corona was likely more complex than expected in 2026.

The 2026 eclipse therefore sits in a middle category. It's not a repeat of 2024, but it's not a quiet-sun eclipse either. An active declining-phase corona, it will likely feature strong streamers extending far into space, but with greater asymmetry, with one side of the corona more active. "It's sunspots specifically near the edge of the sun that dictate what the corona will look like," said French. The sun rotates every 27 days, so any large active region of sunspots rotating onto the sun's edge shortly before Aug. 12 could alter the corona's appearance dramatically. It's why any forecasts of what the corona looks like — which often come from Predictive Science a week before the eclipse — are generally refined on the day of the eclipse.

Red prominences may steal the show

One of the most memorable sights during totality is the appearance of vivid pink or crimson features around the moon's edge. These are usually prominences — immense structures of hydrogen plasma suspended above the sun's surface by magnetic fields. They're often mistaken for solar flares by beginners, such as after the 2024 total solar eclipse.

"Prominences are large magnetic structures that suspend plasma in the atmosphere of the sun, and they glow very bright in a very specific wavelength of light called hydrogen alpha," said French. Prominences are more likely when the sun is active, and because they can last for days or weeks, they are easier to anticipate than a flare. In hydrogen-alpha images taken before eclipse day, observers may be able to see which prominences are present around the solar edge.

The 2026 eclipse may have favorable geometry for sighting prominences. Because the moon will appear only slightly larger than the sun — which contributed to the relatively short duration of totality, at a maximum of just 2 minutes 18 seconds — smaller prominences on different sides of the sun could be visible at the same time. That is different from longer eclipses, where the larger apparent moon can cover prominences on one side before revealing others on the opposite side.

Could a CME be visible?

A coronal mass ejection (CME) is an eruption of plasma and magnetic field from the sun's atmosphere. Seeing one during totality is possible — it happened during the total solar eclipse on Dec. 14, 2020 — but requires luck. "CMEs travel very slowly, so they take several hours to traverse and escape from the sun's atmosphere, so you wouldn't see any motion during an eclipse," said French. "But what you could see, if you're lucky, is a snapshot of an eruption — though maybe a long exposure camera will be more likely to see this than your eye would." Such a view would be rare, but the chances are higher in an active solar environment than near solar minimum.

Predicting the corona yourself

There will be a forecast from Predictive Science, which can be so accurate that some eclipse chasers avoid it, so as not to ruin the surprise of totality. One way to get a general idea is to look at real-time images from telescopes that use coronagraphs to block the sun, such as the COSMO K-Coronagraph, NASA SOHO's LASCO C3 and the GOES CCOR-1. For sunspots, check the latest H-Alpha image from the Global Oscillation Network Group (GONG).

No scientist can say exactly what the corona will look like on Aug. 12, 2026. That will depend on the sun's magnetic activity in the days immediately before totality, the location of sunspot groups, the presence of prominences and the possibility of eruptions. "What exactly we see during the August eclipse will depend on what the activity is that week," said French. "And even if you saw an eclipse a month before or a month after, it could be very different." For a few fleeting minutes over Greenland, Iceland, Spain and the Balearic Islands, the sun's hidden atmosphere will become momentarily visible before vanishing back into the glare, never being seen again in quite the same way.

We're just a few short days away from the Aug. 12 total solar eclipse, when millions will watch as the moon glides across the face of the sun, hiding its light in a wondrous display of orbital mechanics.

The eclipse will unfold during August's new moon phase, as the lunar disk slips silently between the sun and Earth in the daytime sky. Ordinarily, the subtle tilt in the moon's orbit causes its shadow to pass just below, or above our planet, missing it entirely.

However, on Aug. 12, the moon's orbit will carry it into a near-perfect alignment with the sun and Earth, casting its colossal shadow across a 182-mile-wide corridor known as the path of totality, where viewers will get to see the lunar disk fully hide the sun's disk.

The path of totality for the Aug. 12 eclipse cuts through Spain, Iceland and Greenland. Hundreds of millions more watching from outside of this narrow corridor will also bear witness to a spectacular partial solar eclipse, as the moon passes in front of our parent star, without fully obscuring its surface. Those unable to watch the eclipse in person by dint of geography can also follow along online, with details of the livestream to be released closer to the event.

Read on to discover what will happen during each stage of the Aug. 12 total solar eclipse.

Stage 1: The partial eclipse begins

The partial phase of the eclipse officially begins at the moment of "first contact", when the lunar disk takes its first nibble out of the sun — a subtle transformation that will first become visible in the skies over the U.S. state of Alaska at 11:34 a.m. EDT (1534 GMT) on Aug. 12.

You can check out exactly when the partial eclipse will begin from your location and find out exactly how much of the sun will be hidden by the moon using Time and Date's interactive eclipse tracker.

The hour and a half following first contact will see the moon sink ever farther into the sun's disk for those in the path of totality, transforming it from a burning orb into a magnificent shining crescent.

You may notice the temperature drop noticeably, accompanied by a subtle darkening of the sky in the half hour preceding the climactic phase of totality, as the moon reduces the sun to a thin sickle in the evening sky. Pinpricks of light — such as those that shine through a colander, or the gaps in a leaf — will also appear to mirror the scene above, creating a kaleidoscope of tiny bright crescents.

Remember, staring at the sun for even the briefest of moments can lead to permanent loss of vision, so be sure to read our guide on how to view the sun safely and to wear your eclipse glasses or sunoculars during the entirety of the partial phases of the eclipse. You can read our roundup of the best solar viewing equipment to find out more, along with our tips on how to check the quality and condition of your eclipse glasses.

Stage 2: Second contact

Some of the most spectacular moments of an eclipse occur just before and after totality. First, look out for the "diamond ring" effect, as the last sliver of the sun peeks out from behind the lunar disk to appear as a gorgeous celestial jewel, while the outermost layer of our star's atmosphere, the corona, creates a glowing halo around the moon.

Tear your eyes away from the sun for just a second and you may just catch sight of the moon's shadow advancing on you from the west, before it engulfs your surroundings in a false night.

The final seconds before totality will see bright "Baily's Beads" form dazzling points of light on the moon's edge, where the last shreds of the sun's disk shine through the ravines and valleys that scar the ancient lunar surface.

Stage 3: Totality & maximum eclipse

As the last of the sun's surface slips behind the moon, totality begins. This is the climactic phase of the eclipse, when the moon acts like a natural coronagraph to block the brilliance of the sun's disk, ushering in a false night in which our star's outer atmosphere can be seen leaping out from the lunar silhouette.

Totality will last a maximum of 2 minutes, 18 seconds, during which time it's safe to remove your glasses and look at the sun. Just be sure to put them on again before its fiery disk reemerges from the other side of the lunar disk.

That white halo surrounding Earth's natural satellite is the sun's corona — a jacket of superheated gas that surrounds our parent star. Look out for glowing solar prominences leaping outward through the sun's atmosphere, along with the red line of the chromosphere — the layer of the sun's atmosphere beneath the corona — which appears fleetingly at the beginning and end of totality, according to NASA.

The point of maximum eclipse occurs roughly halfway through totality, when the sun's disk is most hidden by the moon.

Eagle-eyed skywatchers may catch Jupiter and Mercury shining to the lower right of the eclipsed sun in the faux twilight experienced during totality, while Venus will appear as a bright star-like object to its upper left. If you're incredibly lucky, you could even spot one of the brightest shooting stars or fireballs of the Perseid meteor shower, which comes to a peak around the same time as the Aug. 12 total eclipse.

Stage 4:Totality ends

The fourth stage of the eclipse comes as the very edge of the sun's disk emerges from behind the moon, marking the end of totality as Bail's Beads and the diamond ring effect play out in reverse, before giving way to an ever-thickening solar crescent.

Stage 5: The partial eclipse ends.

The waning partial eclipse will come to a global end at 3:57 p.m. EDT (1957 GMT), as the moon's silhouette exits the sun's disk in the skies off the west coast of Africa — a moment known to astronomers as fourth contact.

Space.com is on hand to provide expert coverage and on the ground reporting as the eclipse unfolds. Skywatching Editor Daisy Dobrijevic is undertaking an expedition with HX to observe the total solar eclipse from the waters around Greenland, while Skywatching Writer Anthony Wood heads to Spain in a cowboy hat, to catch the orbital showdown with citizen scientists from NASA's Dynamic Eclipse Broadcast Initiative.

Be sure to check out our total eclipse live blog to stay up to date with all the latest news, along with our handy explainer article detailing everything you need to know about the Aug. 12 total solar eclipse.

If photography is your thing then why not read our guide to imaging the total solar eclipse, along with our roundup of the best cameras and lenses for astrophotography? You'll also want to peruse our picks for the best eclipse glasses and viewing gear available in 2026.

Editor's Note: If you capture footage of the Aug. 12 total solar eclipse and want to share it with Space.com's readers, then please send your photo(s), comments, name and location to spacephotos@space.com.

SpaceX launched another batch of its Starlink broadband satellites to orbit today (Aug. 8) from California's scenic central coast.

A Falcon 9 rocket lifted off from Vandenberg Space Force Base today at 12:35 p.m. EDT (1635 GMT; 9:35 a.m. local time), carrying 24 of the internet-beaming spacecraft to low Earth orbit (LEO).

The rocket's first stage returned to Earth as planned about 8.5 minutes later, landing in the Pacific Ocean atop the SpaceX droneship "Of Course I Still Love You." It was the 16th flight for this particular booster, which is designated B1093.

B1093's most recent flight before today was on July 14, when it launched 27 Starlink satellites to LEO from Vandenberg.

Meanwhile, the Falcon 9's upper stage continued carrying the 24 Starlink satellites toward LEO today, deploying them about 61 minutes after liftoff as planned.

Today's launch was the 92nd Falcon 9 liftoff of 2026, and the 71st of the year devoted to building out the Starlink megaconstellation.

Starlink, by far the largest orbiting network ever assembled, currently consists of more than 10,900 active satellites — and it's growing all the time.

Fans who'd grown up on the original "Star Wars" trilogy were adults when they went through the ordeal of Han, Luke and Leia dying on screen. If tears were shed then, however, spare a thought for the kids who'd queued to watch "Transformers: The Movie" back in 1986, only to see many of their heroes expiring in the cartoon spin-off's opening act.

If you can have a bloodbath of sentient machines, this was it, as robots in disguise met their maker at an alarming rate. Ironhide? Dead. Ratchet? No more. Starscream? Pushing up mechanical daisies. Not even the iconic Optimus Prime was spared, as the noble leader of the Autobots met a brutal end at the hands of his nemesis, Decepticon leader Megatron.

This may seem like a recipe for traumatizing the film's target audience — and for many of "Transformers: The Movie"'s young viewers, it was a genuinely disturbing experience. But toy manufacturer Hasbro had ulterior motives for killing their darlings.

Like "Masters of the Universe" (and many other '80s cartoons before and after), the popular "Transformers" TV show was a thinly veiled commercial for one of the hottest toylines on the planet. But, the theory went, the kids who'd been watching since the series debuted in 1984 would now be familiar/bored with the original line-up, and already have the relevant robots in disguise in their toyboxes. By instigating an on-screen cull, Hasbro believed they'd be able to make way for new characters, and keep their young fans coming back for more.

"They created the story using characters that could best be merchandised for the movie," director Nelson Shin (who, in a previous life, had helped to animate the lightsabers in the original "Star Wars") told SFX magazine in 2011. "Only with that consideration could I have freedom to change the storyline. What I tried to focus on was animation-izing the story. For example, when Optimus Prime died, I changed his color from red and blue into gray in order to show that the spirit was gone from his body."

Although screenwriter Ron Friedman was sceptical — "I told Hasbro and their lieutenants they would have to bring him back, but they said no and had 'great things planned'," he recalled to Todd Matthy.com — many of the production team had little idea of the emotional carnage they were about to unleash.

"We didn't know that [Optimus Prime] was an icon," story consultant Flint Dille admitted in an interview on the "Transformers: The Movie" DVD. "It was a toy show. We just thought we were killing off the old product line to replace it with new products.

"Kids were crying in the theaters," he continued. "We heard about people leaving the movie. We were getting a lot of nasty notes about it. There was some kid who locked himself in his bedroom for two weeks."

Forty years on from its original release, a movie with such a high death count looks like a misguided brand extension for a popular Saturday morning cartoon — especially as the TV incarnation hadn't killed anyone across its two seasons to date. But for all its flaws, "Transformers: The Movie"'s storytelling was arguably bolder than any other Hollywood animation of the era.

It was also an impressive technical feat. Although the visuals are a visible step-up from the TV version, Shin (who'd been supervising producer on the cartoon from day one) and his team had to work to extremely tight deadlines to meet the film's release date:

"Time constraints and the sheer amount of work needed were the two biggest challenges, since everything had to be hand-drawn by people!"

The film is set in 2005, some 20 years on from the original series. The Decepticons have taken control of the Transformer homeworld of Cybertron, while human Autobot chum Spike Witwicky (a kid in the TV show) is now grown up with a son of his own. When the villains attack the Autobots' base on Earth, Optimus Prime is fatally wounded, with Megatron also at death's door.

A moment where he pleads, "Don't leave me, Soundwave!" to his loyal cassette player lieutenant is unintentionally hilarious, though still can't compete with a later sequence in which the surviving Autobots dance for joy with some new allies — tonally this movie is all over the place.

Having been cast adrift by the duplicitous Starscream, Megatron runs into a planet-sized robot in disguise named Unicron, who has a similar world-chomping MO as Marvel's Galactus. He wants to get his hands on the Autobots' Matrix of Leadership (the only thing in the universe that can kill him), so he transforms a reluctant Megatron into the souped-up Galvatron, and sends him out to hunt for the McGuffin.

It makes for a madcap 85 minutes as two factions of mostly unfamiliar faces vie to come out on top. The story is mostly told via the medium of fast-paced laser battles, alongside encounters with the surprising number of robotic lifeforms who populate the galaxy. Among them are a five-faced being with a penchant for feeding its fellow machines to mechanical sharks, and some scrapyard dwellers whose conversation is based on snippets from TV ads.

The "Junkions"' leader, Wreck-Gar, is voiced by Monty Python's Eric Idle, just one of the numerous star names whose presence would have meant little, if anything, to the film's young audience back in 1986. Megatron's Galvatron upgrade brought with it the dulcet tones of "Star Trek"'s Leonard Nimoy, reckless Autobot up-and-comer Hot Rod was voiced by "The Breakfast Club"'s Judd Nelson, and Robert Stack (whom readers of a certain vintage will recognize from "Airplane!") was Optimus Prime's ultra-serious number two, Ultra Magnus.

The biggest name of all was a bona fide Hollywood legend, as Orson Welles delivered his final performance as Unicron. Of the "Citizen Kane" auteur, Shin said, "He was co-operative and professional, and I liked working with him," though Welles was apparently a little less convinced.

"You know what I did this morning?" he reportedly complained to a friend. "I played the voice of a toy… I menace somebody called something-or-other. Then I'm destroyed. My plan to destroy whoever-it-is is thwarted, and I tear myself apart on the screen."

The filmmakers also spent more of their reported $6 million budget than they probably should have on a soundtrack powered by '80s hair metal and power ballads — Stan Bush's "The Touch", originally written for Sylvester Stallone vehicle "Cobra", went on to have a second life when the fictional Dirk Diggler "covered" the song in Paul Thomas Anderson's "Boogie Nights".

In hindsight, few of the creative decisions above were conducive to winning over a fanbase who'd have been happy with an extended episode of the TV show. "Transformers: The Movie" subsequently struggled to make back its budget at the box office, an also-ran in a packed summer that also included "Aliens", "Flight of the Navigator" and "Short Circuit".

It's since gone on to pick up a cult following, but still feels like one for completists — ask a casual fan to name a Transformer, and they're going to say Optimus Prime, Bumblebee or Megatron ahead of movie debutants Kup, Arcee (belatedly the first female Autobot) or Rodimus Prime.

Perhaps inevitably, Optimus Prime didn't stay dead for long, and made his inevitable comeback in the next season of the TV show. The good/bad thing about living in a modern pop culture universe is that death doesn't have to be the end.

"Transformers: The Movie" returns to theaters with a 40th anniversary re-release on September 17. It's also available to buy or rent on Amazon Prime Video.