Serious space junkies might be able to identify the comet on which Europe's Rosetta space orbiter landed last year as 67P/Churyumov-Gerasimenko. Everyone else might remember that it kind of looks like a rubber duck. The odd shape has been a topic of debate among scientists, and a new paper in Nature reveals that the rubber duck got its shape in relatively simple fashion: Two comets collided and stuck together, reports the Los Angeles Times. The tricky part, however, is that it had to be a relatively low-speed collision, slow enough that the comets wouldn't obliterate each other. "I would say it's a quite beautiful love story," says Matteo Massironi, one of the scientists on the European Space Agency's Rosetta team, per the BBC.
The revelation came after an analysis of the comet found that layers of material in some parts don't match up with others. That dispelled another theory, that the comet had been sculpted by erosion into its funky shape. "If you put it together, it looks like you have two onions sitting next to each other, not a single onion with a piece taken out," says another scientist. The finding could shed more light on how comets and even planets are formed, notes the Christian Science Monitor. One piece of bad news for duck fans: Rosetta has spied a crack in its neck, raising the possibility that the two original comets will one day go their separate ways again. (The bigger space news today came out of Mars.)