When Worlds Collide

[major_clanger]

... evidence that this may actually have happened. Observations indicate that what was assumed to be a protoplanetary disc around BD+20 307 could be no such thing, as the star turned out to be both a binary and far too old to be in the early stages of forming a solar system. Rather, the interpretation now is that we're looking at the debris cloud from a relatively recent (within the last half-million years or so) collison between terrestrial-size planets.

Alternatively, someone has been testing out the Death Star.