Well, technically it is dwarf planet Ceres....

And it has been in the news this morning because the NASA Dawn probe has just sent back some of the best photos yet taken of these little known planet. 

Although it was first discovered as far back as 1801, it was considered just a very big asteroid until 2006 when the astronomy community chose to create a new classification of "dwarf planet" to cover objects such as Ceres which are smaller than a planet, but too big to be an asteroid. This one object is believed to be made of solid rock, and account for nearly one third of the mass of the asteroid belt between Mars and Jupiter. 

In recent years Ceres has also attracted interest because it seems to have a regular orbit, be large enough to house interesting science and geology, and as the (possible) remnant of an early protoplanet it could give us new information on how our own world may have formed. And perhaps most interesting is that it contains water and ice, leading to speculation that it could be inhabited by some form of extraterrestrial life.

For the moment it is just speculation, but in another month the Dawn probe will reach Ceres and begin a more detailed survey of the dwarf planet. We can only speculate on what it will find, but it is certain to provide new insights into the early evolution of our own Earth and of the solar system.