Does the asteroid belt have gravity

The American space probe Dawn will start on Sunday - assuming sufficient weather conditions. Your destination: Ceres and Vesta, the largest and third largest celestial bodies in the asteroid belt between the planets Mars and Jupiter.

Pasadena (USA) - The researchers hope that Dawn will not only provide information about Ceres and Vesta, but also about the history of the formation of the planets. Because presumably both objects are largely unchanged "protoplanets" from the early days of the solar system.

4.5 billion years ago, a swirling disk of gas and dust surrounded the young sun. The dust particles initially formed small agglomerations, and through collisions and mergers, ever larger objects emerged: first kilometer-sized "planetesimals", then "protoplanets" with a diameter of up to 1,000 kilometers and finally today's planets. One of these freshly baked planets turned out to be a troublemaker: Jupiter, a giant with more than 300 times the mass of our earth, prevented the formation of another planet in the area of ‚Äč‚Äčtoday's asteroid belt with its enormous gravity.

The scientists hope that the protoplanets preserved there are therefore a kind of history book of planet formation. However, collisions with one another have destroyed most of the protoplanets over the billions of years. The asteroid belt is overlooked today with the rubble of these cosmic catastrophes: kilometer-sized, irregularly shaped asteroids that, due to the many collisions, often only consist of loosely packed rock rubble. However, Ceres and Vesta seem to have largely been preserved in their original state and could therefore prove to be a treasure trove for the researchers.

Dawn is scheduled to enter orbit around Vesta in October 2011. Seven months later, she will fly on to Ceres, which, if everything goes according to plan, she will reach in 2015. The onward flight from one celestial body to the next is a novelty in the history of space travel and is only possible thanks to the fuel-saving ion engine of the probe. However, the probe buys this advantage with a particularly long journey: Instead of taking a direct, as short as possible path, the probe slowly moves outwards on a spiral path in the solar system.