Binary star
Astronomers, with the aid of the Hubble Space Telescope, have discovered a unique binary object lurking in the asteroid belt between Mars and Jupiter.

The object, an asteroid first discovered by Spacewatch back in 2006, was reexamined again last September. Hubble took a number of images of the asteroid, designated 288P, just before it made its closest approach to the sun.

Upon studying the images, boffins realised that it was not one but two asteroids of roughly the same size and mass, orbiting each other at a distance of about 60 miles, sporting a comet-esque tail, making 288P the first known binary asteroid that is also classified as a main-belt comet.

This is in contrast to the usual binary asteroids, where one body is much bigger than the other, and the orbits are close.

The photos also revealed ongoing activity in the system.

"We detected strong indications for the sublimation of water ice due to the increased solar heating - similar to how the tail of a comet is created,"team leader Jessica Agarwal said in a statement.

Scientists are hopeful that further study of these unique objects, may provide new understanding as to the origin of our solar system, particularly how water came to be on our pale blue dot.

Astronomers believe that 288P has existed as a binary system for about 5,000 years, when a previous, larger asteroid broke apart due to fast rotation. The team now hopes to find out how common such occurrences are in the asteroid belt.

"We need more theoretical and observational work, as well as more objects similar to this object, to find an answer to this question," said Agarwal.