We’ve never seen images of space as astounding as those from the James Webb Space Telescope, which shared its first cosmic vistas in July. The pictures have left us dazzled, awestruck and excited for more. They also inspired us to reflect on the top space images past and present. These images have moved us because of their drama, beauty or significance. Here’s how eight Science News staffers answered the question: What’s your favorite space image of all time?

Apollo 8 Earthrise, taken in 1968

The Apollo 8 crew orbited the moon 10 times during late December of 1968, capturing this view of Earth.NASA

Lisa Grossman, astronomy writer, chose Apollo 8’s Earthrise as her top space image. She says: The you-are-there, sci-fi-but-it’s-real feeling of seeing Earth over the edge of the moon gets my imagination going. And something about having the surface of the moon in the image gives me deep chills. I can imagine my own feet in those gray craters, my own eyes looking back at my own Earth. It’s wild. It’s eerie. I love it.

I feel similarly about the selfie images from the Mars rovers; here’s NASA’s Curiosity rover at Mont Mercou in 2021.

NASA’s Curiosity rover used a camera on its head and one on its robotic arm to create this selfie with Mont Mercou in March 2021.NASA, JPL-Caltech, MSSS

You can see the rover and the landscape behind it. That’s our robotic avatar on that planet, rolling around doing our work. Though I’m lukewarm about sending people to do extraterrestrial exploration – I think the risks outweigh the scientific benefits – I have always been a sucker for imagining living on another world. Or at least visiting.

JWST’s close-up of Neptune, taken in 2022

Neptune and its rings glow in infrared light in this image from the James Webb Space Telescope. It’s the first direct look at Neptune’s rings in more than 30 years.NASA, ESA, CSA, STSCI, JOSEPH DEPASQUALE/STSCI

Nikk Ogasa, staff writer for physical sciences, says: There are so many awe-inspiring space images out there, but my favorite from this year was the James Webb Space Telescope’s heavenly shot of Neptune. It is stunning. The image captures the planet’s near-infrared glow in unprecedented detail. Not only can you see the glorious rings, but you can also pick out high-flying methane clouds as bright streaks. It blows my mind that we can see clouds on another world that is billions of miles away.

Pillars of Creation, first captured in 1995

After capturing the Pillars of Creation in 1995, the Hubble Space Telescope imaged them for a second time in late 2014 (the image in visible light is shown here).NASA, ESA and the Hubble Heritage Team, STSCI/AURA

Two members of our team selected the Hubble Space Telescope’s second view of the Pillars of Creation, taken in 2014, as their top space image.

Design director Erin Otwell says: My top space image is the Pillars of Creation in the Eagle Nebula. It’s my choice because of the awe-inspiring details and the painterly quality of the composition. To me, this image sums up the feeling of studying the cosmos and of creation itself. The towers of gas and dust where new stars are being born compose an almost solid-looking figure. It looks more like a hand than pillars.  

Maria Temming, assistant editor at Science News Explores, says: I know that claiming the Pillars of Creation as my favorite space image is like saying Starbucks is my favorite coffee. But I don’t care! I love it. I have something of a sentimental attachment to this vista, since it was on the cover of the Great Courses intro to astronomy DVD set that first sparked my interest in space science.

In an infrared light view of the Pillars of Creation, taken by the Hubble Space Telescope in late 2014, stars in and behind the towers of gas and dust are visible.NASA, ESA, Hubble and the Hubble Heritage Team

The iconic, candy-colored images of the pillars in visible light are not the only versions that Hubble has captured. In 2014, the space telescope also took a ghostly picture of the scene in infrared light (above). Light at infrared wavelengths shines through the pillars’ gas and dust, revealing the baby stars swaddled inside these clouds.

Thomas Digges’ view of the universe, published in 1576

In this image published in 1576, English astronomer Thomas Digges depicts stars extending far beyond the solar system.Wellcome Collection

Tom Siegfried, contributing correspondent, chose this diagram as his favorite space image. He says: When Copernicus displaced the Earth from the center of the universe, he pictured the stars as occupying a sphere surrounding the planets that orbited on smaller spheres surrounding the sun. But Thomas Digges, an English astronomer who defended Copernicus, believed the stars extended far beyond the solar system.

In this image, published in 1576, Digges depicted numerous stars beyond the spheres of the planets, suggesting that the universe was “garnished with lights innumerable and reaching up in spherical altitude without end.” With these words Digges was the first follower of Copernicus to suggest that the universe encompassed an infinite expanse of space.

The Milky Way’s black hole, released in 2022

In May 2022, the Event Horizon Telescope collaboration released this first image of the black hole at the heart of the Milky Way.EVENT HORIZON TELESCOPE COLLABORATION

Helen Thompson, associate digital editor, says: Is it extremely blurry? Yes. Is it not even the first time we’ve imaged a black hole? Also yes. But it’s the black hole in our galactic backyard, and we’d never seen it before. There’s something mind-blowing and kind of heartwarming about seeing it for the first time. The Event Horizon Telescope’s first image of Sagittarius A* might not be as pretty as James Webb’s fancy-schmancy pictures, but all of the difficulties that come with imaging black holes and especially this black hole make it so compelling.

Gravitational lensing of quasar 2M1310-1714, captured in 2021

Thanks to gravitational lensing, predicted by Einstein’s general theory of relativity before it was observed, quasar 2M1310-1714 appears as four points of light sitting on a ring around two bright galaxies.ESA, Hubble, NASA, T. Treu

Elizabeth Quill, special projects editor, says: Within the ring of light at the center of this image are a pair of distant galaxies and a much more distant quasar behind them. The mass of the galactic duo is warping the fabric of spacetime, bending and magnifying the quasar’s light to form what are four separate images of the quasar, each sitting around the ring. It’s a visually powerful example of a phenomenon known as gravitational lensing, which was predicted by Einstein’s general theory of relativity before it was ever observed.

My top space image wows me every time. How incredible that the universe works this way. How incredible that the human mind, a motley product of the universe, could foresee it. And not only foresee it; today’s scientists use gravitational lensing as a tool to study otherwise inaccessible regions of space. It’s both humbling and empowering.

Pale Blue Dot, taken in 1990

NASA’s Voyager 1 spacecraft took this parting image of Earth after completing its tour of the solar system in 1990.NASA, JPL-Caltech

Christopher Crockett, associate news editor, says: My favorite space image of all time isn’t of a colorful nebula, or a glittering galaxy, or even a certain supermassive black hole. It’s a single dot, seemingly ensconced in a shaft of light.

After completing its tour of the solar system in 1990, NASA’s Voyager 1 looked back and took a series of parting images – a “family portrait,” it was called – of several planets orbiting our sun. One of the images, which came to be known as the “pale blue dot” photo, captured Earth as seen from roughly 6 billion kilometers away — the most distant image of home anyone has ever taken.

The image, updated with modern image-processing software and re-released in 2020 (above), remains a reminder of why we explore the universe. Yes, we want to better understand how space and time, stars and planets, galaxies and superclusters work, because we’re curious. But all those questions ultimately come back to trying to understand where we come from and how we fit into all that surrounds us.

As Carl Sagan emphasized, nothing better captures just how tiny we are in the grand scheme of things than seeing our entire planet reduced to a mere speck of light.

When I used to give public talks about astronomy, I almost always closed with this image. And I would usually read from Sagan’s reflections on it:

“Look again at that dot. That’s here. That’s home. That’s us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives.… on a mote of dust suspended in a sunbeam.… There is perhaps no better demonstration of the folly of human conceits than this distant image of our tiny world. To me, it underscores our responsibility to deal more kindly with one another, and to preserve and cherish the pale blue dot, the only home we’ve ever known.” More

In February, NASA’s Perseverance rover touched down on Mars and went to work. The rover has seen the first flight of a Martian robot, gotten its drill bit dirty and begun traversing the floor of Jezero crater, thought to be the remains of an ancient lake (SN: 4/30/21).

And what Perseverance is finding isn’t exactly what scientists expected. “The crater floor is super interesting,” says planetary scientist Briony Horgan of Purdue University in West Lafayette, Ind., one of the mission’s long-term science planners. “We didn’t really know what we were getting into from orbit.”

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Perseverance is getting views of enormous boulders that may have been transported by ancient floods, fine rock layers that look like they settled in calm waters, and rocks with large crystals that look volcanic. The rover’s landing site may include a volcanic lava flow from long ago, or signs of an earlier episode of water — or something else.

“It’s not as obvious as we thought,” Horgan says. “Whatever it is, it’s cool.”

Here are some of the image highlights from the rover so far.

Taking the long view

Before the rover landed, the Perseverance team knew that Jezero crater looked like the dry basin of an ancient lake, with a river delta flowing into it. The prospect of finding preserved lake floor sediments made the site good for searching for past life, one of the mission’s primary goals.

This picture, taken March 17, is a mosaic of five images taken with Perseverance’s Remote Microscopic Imager camera. The tilted layers of sedimentary rock (arrows) and other textures in this escarpment were probably formed by interaction between an ancient river and a lake.JPL-Caltech/NASA, LANL, CNES, CNRS, ASU, MSSS

Perseverance took this snapshot March 17 of a steep slope in a part of Jezero’s delta, from more than two kilometers away. The rover probably won’t reach that spot until sometime next year. But already, the rover’s Remote Microscopic Imager camera is uncovering details that could reveal new insight into the crater’s watery past.

For example, the tilted layers of sedimentary rock and cementlike mixtures of coarse sand and pebbles in this rock feature, nicknamed “Delta Scarp,” confirm the delta’s wet history. There are also individual large boulders cemented into the front of the scarp, suggesting that the region saw high floods, says Perseverance deputy project scientist Katie Stack Morgan of NASA’s Jet Propulsion Lab in Pasadena, Calif.

Closer to home

Even eroded outcrops close to Perseverance’s landing site look like they had a watery history. This image of a remnant of part of the delta rising out of the crater floor was taken with Perseverance’s Mastcam-Z camera February 22.

Perseverance’s Mastcam-Z camera took this image (shown in false color) February 22 of a relatively nearby escarpment, which probably preserves ancient lake sediments. Click to enlargeJim Bell/ASU, Mastcam-Z

“Many of us expected these outcrops to be quite uninteresting, based on orbital data,” Stack Morgan says. But images from the ground showed beautiful layers, just like what you would find in a deep-lake deposit.

“We weren’t expecting to find them here, but maybe they’re right next door to our landing site,” she says. These outcrops could be remnants of the edge of the lake that used to fill Jezero crater or could represent an even older lake that was replaced.

Even closer

Perseverance is taking close-ups of the rocks around it too. This closeup image of a rock nicknamed “Foux” was taken July 11 using the WATSON camera on the end of the rover’s robotic arm. The area in the image is only about 4 centimeters by 3 centimeters.

This close-up image of a larger rock was taken with Perseverance’s WATSON camera, part of the SHERLOC instrument on the rover’s robotic arm. It shows textured rocks with an interesting coating that might indicate interaction with water. JPL-Caltech/NASA, MSSS

The textures in this image are fascinating, as are the “crazy red coatings” that are more purple than typical Mars dust, Horgan says. “What rocks are these?” The coatings probably imply alteration by water, and the purple color suggests that they contain some iron, she adds.

Volcanic grains?

Perseverance has also found evidence of igneous, or volcanic, rocks on Jezero’s crater floor. That wasn’t surprising — observations from orbit suggested that volcanic rocks should be there, and scientists hoped to pick up some to help researchers back on Earth figure out the rocks’ absolute ages. Right now, the timing of past events on Mars is based on the sizes of craters and the ages of rocks from the moon, and it’s not extremely precise.

This image, taken August 2, shows mysterious holes and light and dark patches that are potential crystals. The Perseverance rover abraded the rock to prepare for drilling into it. JPL-Caltech/NASA

Igneous rocks on Mars tend to be old and preserve a record of their ages well. “If you want to figure out when things happened on Mars, you want an igneous rock,” Stack Morgan says.

On the ground, though, things are a little more complicated. This rock was the first that Perseverance cleared dust from in preparation for taking a sample. The image shows mysterious holes, which could have been formed by erosion or by air bubbles trapped in lava as it cooled. And the surface is divided into light and dark patches that could be individual crystals, or cemented grains.

If they’re crystals, that suggests volcanic activity, Stack Morgan says — but these crystals are bigger than expected for lava that would have cooled at the planet’s surface. Similar crystals form deep in the subsurface of Earth, where magma solidifies slowly. When lava cools at Earth’s surface, the crystals “don’t have time to grow big,” Stack Morgan says. The next step, she says, is “thinking through how rocks like this could have formed here, if they are indeed igneous or volcanic rocks. How would we get a rock that looks like this?” Maybe this rock formed underground and was transported to the surface, but it’s not clear how.

First sample attempt

That same rock carried more surprises when the rover team tried to drill into it August 6. The drill worked perfectly, to the team’s elation. “One of the most complex robotic systems ever designed and executed worked perfectly with no faults the first time,” Stack Morgan says. “We were like ‘Oh my god, this is amazing.’”

But when they looked inside the tube that was meant to capture the rock sample, it was empty.

“It’s been a bit of an emotional roller coaster,” Stack Morgan says.

Perseverance’s shadow (left) looms over the borehole that the rover made on its first attempt to drill into the Red Planet. The rover’s WATSON imager took a close-up of that hole (composite image at right). These images were taken August 6.JPL-Caltech/NASA, MSSS

The team thinks that the rock was more crumbly than expected, and essentially turned to dust. “The rock was not able to keep its act together,” Stack Morgan says. The drill is designed to sweep the small grains produced in the drilling process, called cuttings, up and out of the sample tube. Stack Morgan thinks the entire sample was treated as cuttings and ended up in a pile of dust on the ground.

There is a silver lining: Now the rover has a sealed sample of Martian atmosphere. And the rover will attempt to take another sample of a hardier rock sometime soon, Stack Morgan says.

In the wind

Mars may have had lakes and rivers in its past, but today the dry, dusty landscape is shaped mostly by wind (SN: 7/14/20). Perseverance has seen a number of dust devils and windstorms sweep through Jezero crater as a beautiful reminder of how environments are always changing, even on a dried-up planet like Mars.

A dust devil swirls across the Martian landscape. This image was captured with the Perseverance rover’s left Mastcam-Z camera June 15.JPL-Caltech/NASA, ASU

“We often think of Mars as this barren wasteland where not much happens today,” Stack Morgan says. “But when you see these dust devils move across the images, you’re kind of reminded that Mars, even though not Earthlike, is its own very active planet still.” More

Peculiar flat regions on Saturn’s moon Titan could be the dry floors of ancient lakes and seas. The suggestion, published June 16 in Nature Communications, may solve a 20-year-old mystery. Starting in 2000, astronomers using radio telescopes on Earth have seen particularly bright radio signals coming from Titan’s equator. Those signals, called specular reflections, occur […] More

SANTA BARBARA, Calif. — It’s one of the most talked-about issues in physics: Two measurements of the universe’s expansion rate disagree. Now, a technique that aimed to resolve the mismatch has produced a third estimate that falls between the previous two. So the controversy endures, scientists report in a study accepted in the Astrophysical Journal.  […] More

Fleets of private satellites orbiting Earth will be visible to the naked eye in the next few years, sometimes all night long.

Companies like SpaceX and Amazon have launched hundreds of satellites into low orbits since 2019, with plans to launch thousands more in the works — a trend that’s alarming astronomers. The goal of these satellite “mega-constellations” is to bring high-speed internet around the globe, but these bright objects threaten to disrupt astronomers’ ability to observe the cosmos (SN: 3/12/20). “For astronomers, this is kind of a pants-on-fire situation,” says radio astronomer Harvey Liszt of the National Radio Astronomical Observatory in Charlottesville, Va.

Now, a new simulation of the potential positions and brightness of these satellites shows that, contrary to earlier predictions, casual sky watchers will have their view disrupted, too. And parts of the world will be affected more than others, astronomer Samantha Lawler of the University of Regina in Canada and her colleagues report in a paper posted September 9 at arXiv.org.

“How will this affect the way the sky looks to your eyeballs?” Lawler asks. “We humans have been looking up at the night sky and analyzing patterns there for as long as we’ve been human. It’s part of what makes us human.” These mega-constellations could mean “we’ll see a human-made pattern more than we can see the stars, for the first time in human history.”

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Flat, smooth surfaces on satellites can reflect sunlight depending on their position in the sky. Earlier research had suggested that most of the new satellites would not be visible with the naked eye.

Lawler, along with Aaron Boley of the University of British Columbia and Hanno Rein of the University of Toronto at Scarborough in Canada, started building their simulation with public data about the launch plans of four companies — SpaceX’s Starlink, Amazon’s Kuiper, OneWeb and StarNet/GW — that had been filed with the U.S. Federal Communications Commission and the International Telecommunications Union. The filings detailed the expected orbital heights and angles of 65,000 satellites that could be launched over the next few years.

“It’s impossible to predict the future, but this is realistic,” says astronomer Meredith Rawls of the University of Washington in Seattle, who was not involved in the new study. “A lot of times when people make these simulations, they pick a number out of a hat. This really justifies the numbers that they pick.”

There are currently about 7,890 objects in Earth orbit, about half of which are operational satellites, according to the U.N. Office for Outer Space Affairs. But that number is increasing fast as companies launch more and more satellites (SN: 12/28/20). In August 2020, there were only about 2,890 operational satellites.

Next, the researchers computed how many satellites will be in the sky at different times of year, at different hours of the night and from different positions on Earth’s surface. They also estimated how bright the satellites were likely to be at different hours of the day and times of the year.

That calculation required a lot of assumptions because companies aren’t required to publish details about their satellites like the materials they’re made of or their precise shapes, both of which can affect reflectivity. But there are enough satellites in orbit that Lawler and colleagues could compare their simulated satellites to the light reflected down to Earth by the real ones.

The simulations showed that “the way the night sky is going to change will not affect all places equally,” Lawler says. The places where naked-eye stargazing will be most affected are at latitudes 50° N and 50° S, regions that cross lower Canada, much of Europe, Kazakhstan and Mongolia, and the southern tips of Chile and Argentina, the researchers found.

A simulation shows the number and brightness of satellites visible from Canada at midnight on the June solstice if 65,000 satellites launch in the next few years. The center of the circle is straight overhead, and the edges mark the horizon. Yellow dots represent the brightest satellites and purple dots the dimmest. Curious about how the satellites might skew your view of the stars? Visit the researchers’ website to check simulations of the visibility near you.Samantha Lawler, Hanno Rein and Aaron Boley

“The geometry of sunlight in the summer means there will be hundreds of visible satellites all night long,” Lawler says. “It’s bad everywhere, but it’s worse there.” For her, this is personal: She lives at 50° N.

Closer to the equator, where many research observatories are located, there is a period of about three hours in the winter and near the time of the spring and fall equinoxes with few or no sunlit satellites visible. But there are still hundreds of sunlit satellites all night at these locations in the summer.

A few visible satellites can be a fun spectacle, Lawler concedes. “I think we really are at a transition point here where right now, seeing a satellite, or even a Starlink train, is cool and different and wow, that’s amazing,” she says. “I used to look up when the [International Space Station] was overhead.” But she compares the coming change to watching one car go down the road 100 years ago, versus living next to a busy freeway now.

“Every sixteenth star will actually be moving,” she says. “I hope I’m wrong. I’ve never wanted to be wrong about a simulation more than this. But without mitigation, this is what the sky will look like in a few years.”

Astronomers have been meeting with representatives from private companies, as well as space lawyers and government officials, to work out compromises and mitigation strategies. Companies have been testing ways to reduce reflectivity, like shading the satellites with a “visor.” Other proposed strategies include limiting the satellites to lower orbits, where they would appear brighter in telescope images but move faster across the sky. Counterintuitively, brighter, faster satellites would be better for astronomy research, Rawls says. “They move out of the way quick.”

But that lower altitude strategy will mean more visible satellites for other parts of the world, and more that are visible to the naked eye. “There’s not some magical orbital altitude that solves all our problems,” Rawls says. “There are some latitudes on Earth where no matter what altitude you put your satellites at, they’re going to be all over the darn place. The only way out of this is fewer satellites.”

There are currently no regulations concerning how bright a satellite can be or how many satellites a private company can launch. Scientists are grateful that companies are willing to work with them, but nervous that their cooperation is voluntary.

“A lot of the people who work on satellites care about space. They’re in this industry because they think space is awesome,” Rawls says. “We share that, which helps. But it doesn’t fix it. I think we need to get some kind of regulation as soon as possible.” (Representatives from Starlink, Kuiper and OneWeb did not respond to requests for comment.)

Efforts are under way to bring the issue to the attention of the United Nations and to try to use existing environmental regulations to place limits on satellite launches, says study coauthor Boley (who also lives near 50° N).

Analogies to other global pollution problems, like space junk, can provide inspiration and precedents, he says. “There are a number of ways forward. We shouldn’t just lose hope. We can do things about this.” More