Asteroid Coming, Ready Or Not

Happy Holidays Mars! Asteroid 2007 WD5, which was just discovered November 20, will approach Mars on January 30 with a 1:75 chance of striking. If it hit Mars, the asteroid would release energy equivalent to a 15-megaton bomb and create a scar the size of Arizona's Meteor Crater. Asteroid collisions are more fun to watch on someone else's planet.

The Dawn spacecraft, which was launched September 27, has fired its ion engines for its journey to the asteroid belt. DAWN will rendezvous with asteroid Vesta in 2011 and Ceres in 2015. We are fortunate to have found meteorites from Vesta, otherwise very little is known about the composition of asteroids. More than just big rocks, the asteroids are new worlds that could even harbour life.

Bode's Law suggests that another planet should orbit between Mars and Jupiter. Ceres, the largest object in the belt, was long classified as an asteroid but recently has been promoted to minor planet. (It's bigger than Pluto.) Some theories suggest that Ceres is largely made of water, and could contain even more water than Earth.

Other observations suggest that Ceres is differentiated into core and mantle, which would mean that it was melted early in its history. Ultraviolet observations have found water vapour near the North Pole. How such a small body could be heated is a complete mystery. Ceres' 10^{21} kg mass could easily hsve coalesced around a small Black Hole.

The Constellation system and Ares V booster will create many possibilities for spaceflight. Because Mars is such a big step, some scientists are promoting a manned asteroid mission. Because of the smaller gravity well, an asteroid mission may use even less energy than landing on the Moon. An Orion could rendezvous with a near-Earth asteroid in a 2-3 month mission.

New presidents like to impose their own Vision, and an asteroid mission would be a Kennedy-like legacy. In addition to the adventure of landing on another world, the mission could easily be justified to Congress. As GHOSTBUSTERS said to the mayor, "You would be saving the lives of millions of registered voters." Are any New York City mayors listening?