Upholding a long-standing tradition of showing us things in space that we have never seen before, the Hubble Space Telescope recently witnessed the break-up of an asteroid.
Asteroid P/2013 R3 was discovered in the Catalina and PanSTARRS sky survey data on September 15th last year. When follow-up observations were made by the giant Keck telescope in Hawaii, three separate objects traveling together within a cloud of dust the size of Earth were revealed. This elevated the level of interest in the object to warrant a look at it through Hubble.
Through the looking glass of Hubble's optics, things grew curiouser and curiouser….
Hubble's perceptive eye made out not three, but 10 distinct objects moving in a pack, the four largest chunks as big as 400 meters across. Also, the fragments are separating from each other at a stately one mile per hour. This could only mean one thing: the small mountain of rock was caught in the act of disintegrating, an event that we had previously only observed in the more fragile and heat-sensitive objects we classify as comets.
Once upon a time, our rudimentary ideal of asteroids was of giant rocks wheeling through space, ranging from house-sized bits to megaliths hundreds of miles across. Most of them are found in the Asteroid Belt between the orbits of Mars and Jupiter, though many have been found roving outside of those bounds and even interloping on Earth's orbit. Over time we have discovered many thousands, and expect their actual numbers to be in the millions.