For thousands of years, Cardea has been known as the Roman goddess of doorways and transitions, a guardian of thresholds. Last week, she joined the celestial ranks of fellow mythological figures like Mars, Venus and Andromeda.

But Cardea is not a planet or a constellation. She is a quasi-moon — a very-real type of asteroid that appears to be doing a special orbital dance around Earth.

The International Astronomical Union, the organization of scientists charged with awarding official names to space objects, selected Cardea through a naming contest that generated more than 2,700 entries. The winning name was submitted by Clayton Chilcutt, 19, a sophomore from the University of Georgia, who participated in the contest as part of an extra credit assignment in an introductory astronomy class.

“I came across Cardea, and when you read the description, it just sounds celestial,” said Chilcutt, an accounting and finance major, adding that his “small contribution to science” was now part of the history books.

The contest was sponsored in part by the popular WNYC audio program “Radiolab,” which featured an episode about a quasi-moon near Venus last year after Latif Nasser, one of the hosts, found himself staring at an astronomy poster on his son’s wall. On the poster, Venus had a moon, and the moon had a quirky name: “Zoozve.”

But after further research, Nasser, who has a doctorate in the history of science from Harvard University, learned that the fleck on the poster designated a moon was not technically a moon, but also not not a moon, as he describes it.

A planet orbits around a star, and a moon orbits around a planet. Quasi-moons orbit the sun but are close enough to planets to seem like tiny moons “doing this double Hula-Hoop dance out in space,” Nasser said.

Nasser also learned that Zoozve’s real name was not the pile of consonants but simply a misinterpretation from the poster’s artist: Zoozve was actually 2002-VE. Still, he convinced the astronomical union, which usually approves only mythological names from culture or literature, to give 2002-VE the name Zoozve.

“It was totally shocking and it felt like a little coup, like a little nudge for silliness in the universe,” Nasser said.

But Zoozve was not alone. In fact, Earth had a handful of quasi-moons, too, that were eligible to be named (only one had a non-alphanumeric designation, Kamo’oalewa).

“Nobody seemed to care!” Nasser said. “We care, I care, a lot of people would care.”

So in June, “Radiolab” and the astronomers union teamed up to find a mythological name befitting of 2004 GU9, a quasi-moon discovered in 2004 by the LINEAR project in Socorro, New Mexico. The astronomical union said one of its closest approaches to Earth will be in October 2026, when it’s about 18.5 million miles away.

The contest solicited names from more than 100 different countries. Many entrants wrote moving tales of mythological origin stories, some from their own cultures and others from oceans away, and what a name like this would mean to the world. The astronomer’s union weeded out duplicates, names already in use and “clearly not mythological names where people didn’t even try,” Nasser said, like Mooney McMoonface.

“Radiolab” helped assemble a star-studded panel of astronomers, journalists, teachers, students and even a few celebrity nerds, including Bill Nye, Penn Badgley and Celia Rose Gooding. The panelists whittled the list down to seven finalists — two of which came from the same University of Georgia course — and then released the list to the public.

Other finalists included Bakunawa, a mythical dragon from Philippine folklore, who was said to rise from the ocean to swallow the moon; Ehaema, or “Mother Twilight” in Estonian folklore; and Tecciztecatl, an Aztec lunar god who aspired to be the sun.