The Philae lander offers new clues to cosmic biology
A new finding from the Rosetta spacecraft upsets a longstanding theory
A pair of sort-of comets pose a puzzle for astronomers
The difference between an asteroid and a comet was always thought fixed—but now a new paper says the two celestial bodies may be more similar than we thought
It's a comet! It's an asteroid! It's a bit of both—and it's one of the niftiest little members of the solar system
Every comet that’s ever been spotted is a fugitive on the lam. Comets really have no business visiting the inner solar system at all. They don’t remotely...