Outer space is everywhere: Not only are we physically surrounded by it, but we’re inundated with images of it, both real and fictional. NASA’s long-lived Cassini mission is ending this week, just after its even longer-lived Voyager mission marked its 40th anniversary. SpaceX is about to launch the most powerful operational rocket in the world. Star Trek is returning to TV, The Martian author Andy Weir is returning to bookshelves, and Destiny 2 and a new Metroid release are bringing gamers back to the stars. Please join us at The Ringer as we celebrate and explore the cultural resonance and science of space all week long.

Like a lot of hormonal teenagers, Doug Ellison’s life was forever altered when he discovered the wealth of images available for free on the internet. He’d caught tantalizing glimpses before, but they never revealed everything, and his appetite was insatiable. “What was being shown on TV wasn’t enough,” he recalls. “I was like, ‘I have to get these pictures.’” On the internet, he could access whatever he wanted, with none of the intriguing stuff censored.

I’m referring, of course, to the complete archive of images transmitted by Mars Pathfinder, a robotic spacecraft that landed on the red planet in the summer of 1997 and disgorged a roving probe named Sojourner, the first human-made rover to roam beyond the Earth or the moon. Ellison, now the visualization producer at NASA’s Jet Propulsion Laboratory, remembers when and where he saw the Sojourner image that changed his life. It was the summer before he started at university, and he didn’t have an internet connection at his home in rural England. Desperate for a fix after coming down from an earlier visit he’d paid to NASA’s Pathfinder site while waiting for his university interview, he biked to a nearby town and bought dial-up access for £8 an hour, watching another world appear pixel by pixel on a 14-inch screen. “I was there for like two hours as these images slowly crawled down onto the computer so I could save them on floppy disks and take them home,” he says.

One of those images was a compiled panorama that looked like this:

“It was crudely assembled,” Ellison says. “They bolted together the mosaic really, really quickly. You can see all the stitching lines. You can see the colors aren’t lined up properly. It’s messy. It’s really heavily compressed. But it felt to me like this was a raw exploration in front of me. Like this was what Mars looked like this morning. And from that moment I knew I wanted to be involved in space in some way.”

Ellison, who now has a gigabit connection at home that costs a lot less than £8 an hour, got what he wanted: His job involves targeting and taking pictures with the camera on one of Sojourner’s successors, Curiosity. Ellison has gone back and reassembled the old Sojourner image from raw data, and it’s never far from his sight. It’s the only image he has on the wall at his home, where he sees it several times a day. “Every time, I take a little glance at it, and I get that little spark of what that was like in 1997, when instead of being a dot in the sky or [on] a map, Mars was turned into a place,” he says.

“I personally have not seen any other science that has benefited as much [from the internet], because it’s a visual medium.”

—Author and astronomer Phil Plait

Ellison wasn’t the only future scientist ensnared by the mid-’90s melding of astronomy and the internet. “I would not have had that moment that led me to planetary science for sure, if it weren’t for this public sharing of images by the internet,” says Emily Lakdawalla, a planetary scientist and senior editor for space education and advocacy organization The Planetary Society. “As a kid who had grown up being super into Transformers, seeing an active, autonomous robot exploring another planet was kind of like science fiction come to life.” Astronomy turned Mars and other formerly alien locations into recognizable places just as new technology on Earth turned the internet into a place capable of instantly introducing otherworldly images to a large audience. Thanks to its uniquely visual nature, its ability to bypass linguistic barriers, and the universal questions its explorations raise, astronomy has become the internet’s most symbiotic science. The internet and astronomy have matured in tandem, and no field of study has benefited more from the ability to spread its message to the masses than the science of space.

“I personally have not seen any other science that has benefited as much [from the internet], because it’s a visual medium and people also are interested in astronomy stuff,” says author and astronomer Phil Plait (a.k.a. “the Bad Astronomer”). “I think it’s possible that astronomy taps into those bigger questions more [than other sciences]. Where are we, why are we here, where are we going? What's a black hole? How’d the universe get to be the way it is? These are huge questions, and we can answer some of these a little bit, at least. And on top of that, the pictures are just stunning.”

Two weeks ago, a user on Reddit’s r/space somewhat comically asked the site’s admins to stop the subreddit’s stream of photos, GIFs, and videos. The request wasn’t well received. “Speak for yourself,” went one reply. “r/spacewithoutpictures doesn’t exist yet,” another user wrote. “You could create it.” No one has.

Pictures give space its power, making it more memeable than any other exercise that demands as much math and programming. Whether an astronomical announcement contains the dramatic first photos of a faraway world or seeks to explain some arcane concept, there’s always an image attached, even if it’s only an artist’s conception.

In December 1993, spacewalking astronauts corrected the optics of the 3 1/2-year-old Hubble Space Telescope, whose infinitesimally flawed mirror had been producing unfocused images ever since it reached orbit. With that imperfection patched, astronomers gained access to images of incredible clarity that exposed previously invisible swaths of the sky. And so did the public, in part because the fledgling World Wide Web had recently leveled up too. In a case of fortuitous timing, the Mosaic web browser had launched earlier that year, bringing with it the capacity to display inline images accompanied by text instead of opening them in a separate window. For the first time, images could be displayed on the internet almost as they are today—just much, much more slowly. Cue the dial-up modem sound.

Plait dates his use of networked computers to well before there was “the web,” and had spent two years earning his doctorate by working with fuzzy Hubble images before the telescope’s vision cleared. He remembers when Mosaic arrived, but he also remembers the internet traffic jam that occurred whenever the era’s restrictive bandwidth couldn’t keep up with a torrent of media beamed back from outer space. “I remember the internet physically slowing down a lot of the times when some big thing would happen,” Plait says. Ellison adds, “Back then, the technology really made you work for it.”

A bunch of “big things” arrived right around that time: Comet Shoemaker-Levy 9 caused a stir in the astronomical community when it slammed into Jupiter in 1994, with the Galileo spacecraft—the first ever to orbit Jupiter—in position to see it. Comet Hale-Bopp, one of the brightest ever recorded, was visible to the naked eye for about 18 months beginning in the spring of 1996. But the biggest of the big things was Pathfinder, which caught Ellison’s (and everyone else’s) attention. “The internet was still quite young, and Pathfinder was regarded as like the first internet sensation,” he says.

In a time before cloud computing, NASA braced for impact by setting up mirror sites that would ease the strain on JPL’s servers caused by what was projected (accurately, it turned out) to be 60 million to 80 million hits in one day. The mirror plan mostly worked, although some regions were still hit hard; in France, where the phone system carried all of the nation’s internet traffic, the government asked its citizens to stop scoping out Pathfinder pics so that the country could communicate. “The French internet was brought to its knees by Mars,” Ellison says. NASA’s website dubs it, “The Day the Internet Stood Still.”

That hiccup qualified as a growing pain, but it also demonstrated how enormous the appetite for space-based content was. Astronomy went viral just as the world was discovering what “went viral” meant.

this image from Cassini has me almost in tears. It's called "The Day the Earth Smiled" (2013). that little dot on the lower right is us. pic.twitter.com/Ybuk9nbDZ8 — rae paoletta (@PAYOLETTER) September 8, 2017

It wasn’t preordained that the proceeds of NASA’s internet-age missions would end up on the internet. For most of the Space Age, all but the most famous astronomical images were confined to more limited means of circulation: ham radio, science books and magazines, newsletters with low image quality, and public television. Proliferation of photos “was not as immediate, and you had to be an enthusiast in order to see them,” Lakdawalla says. “There wasn’t kind of the penetration into wider popular culture that is so easy to do with social media.”

And while images from the Voyager mission had trickled onto the proto-web in the mid-’80s, a proprietary instinct held sway among some old-guard astronomers who were used to parceling out data in dribs and drabs after they’d taken their sweet time to sift through it.

“There was kind of a philosophy out there when I was in graduate school and when I was a young researcher,” says Jim Bell, the author, professor, JPL visiting scientist, and president of The Planetary Society. “I could paraphrase it like, ‘Well, you know, I’m a grand old man in this field, and I spent 20 years proposing this mission and designing this camera, and dammit, I’m going to write the papers on it and no one’s going to get the data until I say so.”

Bell says that exclusionary attitude started to weaken with an early citizen-science project called Mars Watch, whose extremely ’90s-looking website is still online. Mars Watch was a worldwide network of hundreds of observers who banded together to monitor Mars’s weather using Hubble and ground-based equipment. Bell and his colleagues collected that crowdsourced data and relayed it to JPL, whose Mars orbiters had big blind spots because they were stationed close to the poles. An early warning from Mars Watch could help tip off the operators of the solar-powered rovers that a sun-obscuring storm was approaching.

Mars Watch was far from the first loosely organized group of amateur astronomers, but it was one of the first to demonstrate the democratizing potential of astronomy’s new age. “It’s not a coincidence that astronomy is very popular on the web,” says Plait, who points out that improvements in the quality and cost of digital cameras were partly driven by the need to develop detectors for Hubble. “It’s a digital medium.” Again, technologies dovetailed in a way that tied astronomy and the internet together. “Right around the same time as the internet got developed, we started to see the proliferation of affordable digital cameras,” Bell says. “Lots of folks found themselves in a situation where, ‘Oh, I can now take digital images and get instant feedback and connect that to my telescope. … And I can share that with people around the world very, very quickly.’”

Gradually, outsiders such as Bell and Ellison—who made his own contribution to the community by founding the Unmanned Spaceflight forum for fellow imaging enthusiasts—gravitated toward the inside, bringing their open-book ethos with them. “All of us were just tickled pink with this concept of being able to share all this stuff in real time,” Bell says. “As a number of us transitioned from the telescope world to the Mars mission world, as more and more missions came online in the ’90s and 2000s, that philosophy transitioned into putting the images from the rovers on the internet in real time.”

When the Mars Exploration Rover Mission deployed the Spirit and Opportunity rovers in January 2004, Bell was the team leader for the vehicles’ panoramic cameras. He and Steve Squyres, the mission’s principal investigator, decided to unbar the doors to the data. Not only had they been burned in the past by more senior astronomers who were protective of their turf, but they felt obligated to repay the public’s investment. NASA missions are taxpayer-funded, and the legislation that spawned NASA in 1958 charged it with “disseminating information about its programs to the widest extent practicable,” which ostensibly made sharing part of the agency’s mandate.

“We decided, as soon as the images hit the ground from the rovers, they would automatically go out onto the internet,” Bell says. “There wouldn’t be any vetting, there wouldn't be any ‘Hang on to it for an hour.’ … Some of our colleagues were shocked and aghast: ‘You’re going to get scooped, people are going to write papers, and you’re going to miss the opportunity to get credit.’ None of that really happened. What happened instead was that we helped to foster just a wonderful and vibrant amateur community of armchair Mars travelers who were putting mosaics together and processing images and posting them on their own websites.”

Although some missions still release only lower-resolution data during a prearranged window of exclusivity that allows the original researchers time to publish, Bell and Squyres’s decision set a precedent that’s been followed by many missions since, including Cassini, Phoenix, the Mars Reconnaissance Orbiter, and Curiosity. The trend has reached its apex with the addition of imaging gear to spacecraft that weren’t initially supposed to include color cameras (or any kind of camera), such as the Juno probe (currently orbiting Jupiter) and the Mars InSight lander, which launches next year. Even if it’s not a scientific necessity, it’s now virtually taken for granted that any future craft will carry equipment capable of bringing the internet along for the ride. “It’s sort of expected,” Bell says. “‘Are you going to share those images with everybody?’ And if your answer is no, eyebrows are going to go up.”

Most experts I spoke to agree that the biggest benefit of astronomy’s productive partnership with the internet is deepening the public connection to missions that might otherwise remain the province of a small group of scientists—and, by extension, getting more of those missions approved. “The public wouldn’t be as enthusiastic about funding NASA missions if it weren’t for the imagery that comes out of NASA missions,” Lakdawalla says.

But there’s also valuable science and exploration underway that wouldn’t be possible without public participation, from measurements of the Mars and Jovian atmospheres, to planet-hunting—which recently turned up the irregularly and mysteriously dimming “Tabby’s Star”—to other tedious-but-vital tasks that there are never enough scientists to complete.

“The public wouldn’t be as enthusiastic about funding NASA missions if it weren’t for the imagery that comes out of NASA missions.”

—Planetary scientist Emily Lakdawalla

Pamela Gay, who went from working with crowdsourcing site Galaxy Zoo to cofounding citizen-science hub CosmoQuest, says the latter site’s members have partnered with NASA’s New Horizons mission to search for remote Kuiper Belt Objects and are now making high-resolution maps of the Moon, Mercury, and Mars; charting possible landing sites for the Mars 2020 rover; identifying targets for the OSIRIS-Rex asteroid study; and adding labels and metadata to images snapped by the crew of the International Space Station. “We’re that project that’s in the background doing the boring work that has to be done to allow those amazing breakthroughs to take place,” she says. Ellison notes that NASA is now baking contributions by citizen scientists into its mission planning. “We went from amateurs contributing data to scientists, [to] scientists now saying, ‘Here’s our data, have a play with it,’ and now we’ve reached a point where the scientists are saying, ‘Here’s some data that we’ve taken. We need you to process it for it to be any good,’” Ellison says.

Astronomy isn’t the only science that’s capitalized on the internet’s ability to break down barriers between hobbyists and specialists—the biosciences and climate sciences have benefited from crowdsourcing too—but because of NASA’s early embrace of the web, “astronomy was able to take the leap to being fully digital ahead of many other projects,” Gay says. Ellison believes that astronomy’s internet fame can serve as an example to other sciences of “how capable the public are, how well they will step up to challenge if asked, and how well the amateur community and the scientific community can overlap, coexist, and benefit from one another.”

The only downside of astronomy’s viral power is that misleading space science spreads quickly. Plait, in particular, has devoted much of his work to debunking bad science and misconceptions about astronomy. But even he admits that the costs of hoaxes about Nibiru, massive Mars, pareidolia, or even bogus asteroid impacts are low relative to those of the anti-vaccine movement or climate-change denial. “Astronomy has suffered because of misinformation that’s gotten spread rapidly, but probably not to the extent of other sciences, like climate science or evolutionary science or vaccine science [and] medical science,” he says. “I don’t think people are dying because of astronomical misinformation.” And when an astronomical image is doctored to deceive the public, Plait or another well-informed source can always correct the record by pointing people to the original, which usually sits in a freely accessible archive along with thousands of other images from old missions whose scientific value has yet to be tapped.

Almost 25 years after Hubble repairs and the debut of Mosaic helped make the internet and astronomy inseparable, the two are tighter than ever, as higher bandwidths and higher resolutions form a match made in the heavens. “You wouldn’t think live video would be very conducive for astronomy, but it turns out it is,” Plait says, soon after solar-eclipse mania swept the United States. “All of the astronomy images and video and all of this stuff has grown at roughly the same pace the web has grown.” Avenue Q wasn’t wrong: The internet is for an entirely different type of image. But it’s also for astronomy.