DAWN Brings a Vesta Mystery

The DAWN spacecraft orbiting Vesta has allowed scientists to create this false colour model of the asteroid. Vesta's South Pole contains an enormous depression hundreds of kilometers across. At first the depression was thought to be an impact crater, but it's shape is all wrong. More mysterious, at the South Pole is an enormous mountain 15 km high, one of the tallest peaks in the Solar System. Scientists are baffled as to how such a huge mountain could form here.

We are fortunate to have samples of Vesta that arrived on Earth as meteorites. Vesta meteorites show signs of volcanic heating. How heating could occur on an asteroid has also been a mystery. The answer to these puzzles may be something that formed shortly after the Big Bang.

Vesta's formation could be explained if it formed around a small Black Hole. As seen on Saturn's moon Enceladus, the singularity would cause the South Pole to be heated. This permanent hot spot would support volcanic action almost indefinitely. A mountain would build up until it rivaled Olympus Mons in height. Lava rocks from the volcano would be ejected into Space, a few of them reaching Earth as meteorites. Even an asteroid could potentially be home to a Black Hole.

Vesta Turns

The Dawn spacecraft took this series of views of asteroid Vesta. We are fortunate to have meteorite samples of Vesta, blown off in some cataclysm. Vesta rocks show signs of melting, as if born in a volcano. What caused pieces of Vesta to be blown off is a mystery. Scientists have suggested a nearby supernova explosion, but such a catastrophe would have affected other bodies such as Earth.

A minor planet like Vesta could also be home to a tiny Black Hole. This dwarf planet would have formed around the singularity like a pearl around a grain of sand. The Black Hole would be too tiny to swallow Vesta, but the small amount it did eat would make the interior warm. A Black Hole could make Vesta volcanic, even sending some pieces hurtling into Space. Vesta contains tiny clues to the formation of our planet Earth.