The US space agency announced that its Dawn mission would go into orbit around asteroid Vesta on 16th July 16, 2011. This is a robotic satellite which will be at the 530km-wide body for a year before going to the “dwarf planet” Ceres.

Recent pictures of nearing of Dawn towards Vesta displays the giant rock in exceptional detail. As an effect of colossal collision in the past which destroyed its south polar region, the asteroid appears like a punctured football.

The fourth asteroid to be recognized in the great belt of rocky debris moving between Mars and Jupiter, Vesta was discovered in 1807. At one time its great scale gave it the status of another planet but afterwards it lost this status as scientists came to know more about the variety of objects in the solar system.

Cautious and Close

This meeting of Dawn is happening about 188 million km (117 million miles) from Earth. The search is driven by an ion engine and engineers have placed the spacecraft on a way to be confined in the gravitational field of Vesta. They are anticipating confirmation from the satellite on Saturday about its safely circling the rock.

Originally, Dawn will be about 16,000km (9,900 miles) from the asteroid, but this distance will get decreased in due course of time. The researchers of the mission anticipate getting within 200km of the surface but the group doesn’t wants to take any unwanted dangers. “We would like to get as low as possible but if we crash Dawn, Nasa would understandably be very angry at us,” told main investigator Chris Russell.

Asteroids will inform about the previous days of the Solar System. These moving rocks are portrayed as debris left after the formation of planets. Vesta and Ceres may create an interesting topic. Both of them are evolved bodies – objects which had heated up and started separating into different layers.

Surface Detail

“We think that Vesta has a metal core in the centre – an iron core – and then silicate rock around it,” explained Dr Russell. “And then, sometime in its history, it got banged on the bottom and a lot of material was liberated. Some of this material gets pulled into the Earth’s atmosphere. One in 20 meteorites seen to fall to Earth has been identified with Vesta,” he added.

Ceres is at 950km in diameter and is the largest and heaviest body in the asteroid belt, did not develop like Vesta. The researchers find it probable that it stores a lot of water in a mass of ice deep below the surface.

The mission of Dawn at Vesta will be to record the surface of asteroid. The mission carries tools to spot the quantity of mineral and elements in the rocks. It will search for proofs of geological processes like mountain building and rifting. The group is really interested in knowing how the surface of Vesta has been reshaped over time by effects and even flow of lava.