The Hubble Space Telescope spied an asteroid breaking up into as many as 10 smaller pieces — a phenomenon that scientists have never seen before.
While we've seen more fragile comet nuclei disintegrate as they approached our Sun — the massive comet ISON famously broke apart near the Sun last year and was seen again in pieces shortly after — scientists haven't ever observed a breakup like this in an asteroid. This illustration, below, shows one possible explanation for the
disintegration of the asteroid, which has been dubbed P/2013 R3
We know that P/2013 R3 didn't collide with another asteroid because
it didn't explode, but rather gradually broke apart. This means that it
had a weak, fractured interior, likely the result of it surviving
near-death collisions with other asteroids over the past 4.5 billion
years. Now it's disintegrating because the sunlight is speeding up its
rotation.
The photos below, which the Hubble telescope captured on Oct. 29, 2013, show the asteroid as it broke apart.
The grainy spots that form the comet-like tails are actually dust coming from rotating rock.
