How Venus Ended Up with a Mini-Moon Named Zoozve

Brian Skiff (Lowell Observatory), who has been a research scientist for almost 50 years, is no stranger to the discovery of new small bodies in the solar system. He has found dozens of asteroids and discovered or co-discovered more than 40 comets, about a dozen of which bear his name. So when he found another fast-moving asteroid while analyzing recent images in the Lowell Observatory Near-Earth Object Search one night in November of 2002, it seemed fairly routine.

“This thing was going about four degrees a day, so it was obviously a nearby object, given that main-belt asteroids go about a quarter of a degree a day,” Skiff says. As with any fast-mover, he interrupted the regular observing plan to go back for follow-up observations that night, so that the object would not get lost. As usual, he reported the data to the Minor Planet Center. And then he forgot all about it. “Obviously it was just a near-Earth object, and a nice bright one and a nice thing for us. So we moved on and didn’t think anything of it,” he says.

He didn’t even realize when, a year later, two other astronomers, Seppo Mikkola (Tuerlo Observatory) and Paul Wiegert (U. of Western Ontario), analyzed the object’s orbit and found it was the first of its kind. The object, which had received the temporary designation 2002VE₆₈, is a quasi-moon. It appears to orbit Venus but is in fact not gravitationally bound to it, but rather circles both the planet and the Sun in a complex and ultimately unstable orbit. Calculations show it’ll leave Venus’s influence altogether within about 500 years.

Such quasi-moon orbits had been predicted as a theoretical possibility way back in 1913, but none had ever actually been seen before. This find therefore represented a whole new class of minor bodies in the solar system. Since then, at least eight others have been found, one of them associated with Neptune and seven of them orbiting alongside Earth. Earth's tally includes one mini-moon, found just last year, that appears to have the most stable quasi-satellite orbit yet, with a lifetime of around 4,000 years before it departs Earth's gravitational influence.

Skiff wasn’t aware of any of this follow-up work until he got a call last year from Latif Nasser, co-host of the popular science podcast Radiolab. Nasser was trying to track down the origin of an odd name he had seen on an artistic poster of the solar system that was hanging on the wall of his two-year-old son’s bedroom. The poster seemed to show that Venus had a moon, whose name was labeled as “zoozve”. Nasser made some calls to astronomers at NASA, who confirmed his suspicion that no, Venus does not have a moon. Perplexed, he kept digging to try to figure out where the odd object with the odd name had come from.

He eventually tracked down the poster’s creator, artist Alex Foster, in Margate, UK, who was also taken by surprise by the question. They eventually figured out what had happened: Foster had found the name of the asteroid, 2002VE, on a list of solar system moons somewhere online (he doesn’t remember where). When transferring it to his poster, he misread his own handwriting, and instead entered it on the poster as ZOOZVE. Mystery solved.

“It's a bit surreal and strange to think how it’s all turned out,” Foster says, “all starting with making an error years ago when I made the print.” He adds that “it's affected me so far mostly through a huge amount of orders through my online shop, which I'm very grateful for.”

But Nasser couldn’t just leave it there. “By then, I don’t know, I had sort of fallen for this thing,” he tells Sky & Telescope. “I think if it had been labeled on the poster as 2002VE, for whatever weird mystical reason, I don’t think I would have fallen in love with it quite as hard as I did.” But somehow the funny-sounding name Zoozve had really struck a chord with him.

“So I was like, ok, can we actually change it?” Nasser set about learning the somewhat arcane process for the formal naming of asteroids, and asked for Skiff’s help.

Skiff was initially unimpressed. As the original discoverer, he was authorized to propose an official name for the object, as he had done for many of his previous asteroid discoveries. Once, after discovering four consecutively numbered asteroids in a row, he suggested naming them after the four Beatles. (Name proposals are then submitted to the International Astronomical Union (IAU) for approval.)

But Zoozve didn’t grab him: “I was like, so would you name it Zoozve?,” Nasser recalls. “And he’s like no, definitely not.”

Initially crestfallen, Nasser, who is known for his persistence, told Skiff the whole story about the poster and the mistaken reading of the sloppy notes that resulted in the odd name, and about the odd and unusual nature of the object’s orbit — and he won him over. Nasser ended up writing up the formal proposal (which is limited to 360 characters), and Skiff and the observatory agreed to formally submit it to Gareth Williams (Center for Astrophysics, Harvard & Smithsonian), who acts as secretary for the International Astronomical Union’s working group on solar system small-body nomenclature.

Williams was initially skeptical as well, noting that the IAU guidelines recommend that names for objects that cross Earth’s orbit be based on mythology. By the time Radiolab’s episode on Zoozve aired, the decision was still not final — two of the committee’s members had not yet voted, and the outcome was too close to call.

“We were so nervous,” Nasser says, thinking that the uncertainty would be frustrating for the audience. “But it turned out to be a cliffhanger — everybody took it the opposite way. Instead of being unsatisfied, it made people much more invested.” Some people said they kept refreshing the Radiolab website for days to see if there had been any news about the naming.

And sure enough, after the final votes came in, the name was (narrowly) accepted. On February 5th, the IAU included it on its latest list of new asteroid names. The public’s interest peaked, making that Radiolab episode one of the most-downloaded in the podcast’s last year; their Twitter feed about it has racked up 16.9 million views so far. “It went bananas! A bunch of people told me they’re naming their dogs or cats Zoozve,” Nasser says. Foster, the artist who started it all, is thinking of getting “Zoozve” as his first-ever tattoo.

The story doesn’t quite end there. Having become so interested in the subject of quasi-moons, Radiolab is about to launch a competition to come up with a new name for one of the at least seven quasi-moons that orbit the Sun alongside Earth. (The only other planet known to have a quasi-moon sharing its orbit is Neptune). While details are still being worked out, one thing is clear: This time, the name really will have to be based on mythology.

They’re still figuring out the rules, but Nasser says “we don’t want it to be an outright voting contest – we don’t want ‘Moonie McMoonface’” – referring to a naming contest in the UK that resulted in a research ship being named Boaty McBoatface. “My co-host suggested Quasimoondo, which I think is hilarious,” he says.

Nasser says that part of what excited him about this whole process was the fact that such fascinating new findings as the existence of quasi-moons is still possible. “I just had the idea that science is a textbook, it’s written, it’s published,” he says. “I like the feeling that Earth has a quasi-moon that was just discovered last year. There’s still some pretty basic stuff that we just don’t know about what’s going on, even right around us, that we’re still figuring out!”

Skiff echoes that sentiment. “This is an example of how we live in this tremendously dynamic environment in the solar system. Even though it’s four and a half billion years old, it’s still tremendously dynamic, and we’re finding out about it as we go along.”

And Nasser delights in the thought that anyone can play a role in the naming process of the quasi-moon in their contest: “For kids, and for adults too, they could be part of that – ‘I’m going to help name a thing that’ll be in a textbook one day!’ It makes you feel like you’re part of the action.”

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Editorial note (Feb. 9, 2024): The article has been updated to note that Gareth Williams acts as secretary for the IAU working group on small-body nomenclature.