We're learning a lot about the brightest asteroid because of a spacecraft visit a few years ago. That spacecraft is now visiting the biggest asteroid. Continue reading →
¡SkyCaramba! Weekly astronomy blog for the week ending March 21, 2015
The biggest asteroid between Mars and Jupiter may hold more water than Earth. Ceres is thought to have a rocky core and a thick ice crust. Water vapor plumes, possibly coming from icy volcanoes, have been detected coming off its surface.
Quite a lot of asteroids are oddly shaped. Astronomers describe their shapes as potatoes. Ceres happens to be round.
Ceres is the first asteroid discovered. Giusseppe Piazzi spotted it on the first night of 1801. The best telescopes of the time couldn’t resolve it as anything but a dot. In that way, it was much like a star. However, it moved among the stars like a planet. Astronomers weren’t sure what to call this type of object at first, but they eventually settled on asteroid which means star-like.
The views weren’t much better by the time Heinrich Olbers discovered the fourth known and brightest asteroid, Vesta, on March 29, 1807. Astronomers were beginning to suspect there were many more such ...