Vesta an asteroid full of surprises

Berlin, Germany (SPX)
Sep 19, 2011

Varied impact craters, valleys, canyons and mountains among the highest in the Solar System - the 3D images and videos of the asteroid Vesta created by scientists at the German Aerospace Center (Deutsches Zentrum fur Luft- und Raumfahrt; DLR) reveal a most unusual celestial body. The US Dawn spacecraft, carrying a German camera system on board, has been orbiting the asteroid since July 2011.

"Vesta has totally surprised us," says Ralf Jaumann, Head of the Planetary Geology Department at the DLR Institute of Planetary Research in Berlin-Adlershof. The topographical maps are necessary to study the asteroid, whose orbit lies between those of Mars and Jupiter.

The latest 3D images, which show the whole asteroid, make something very clear - Vesta holds quite a number of challenges for the scientists on the Dawn team. "For example, we can see a very large impact crater in the south polar region, the likes of which we have never seen before," emphasises Jaumann. The shape and structure of the crater differ from every other impact crater in the Solar System. "We are unable to find similar craters on other bodies, and cannot yet explain exactly what has caused it."

Another critical question faced by the planetary scientists is whether or not there has been volcanism on Vesta. The numerous impact craters are not making this easy for scientists. "Any evidence of volcanic activity has been covered by impact ejecta and our current challenge is to find traces of volcanic deposits," explains Jaumann.

Dark material associated with craters that appears in some of the 3D images might provide the scientists with information on potential volcanic activity. But it could also be the remnants of the impacting body, in which case, the search for signs of volcanism must continue.

Anaglyph: landscape with craters If an explanation could be found for the features that appear on the images and video obtained from orbit at an altitude of 2420 kilometres, the scientists would be considerably closer to fulfilling the aim of the Dawn mission.

The asteroid could provide information about the birth of the Solar System. When the planets were forming, about 4.56 billion years ago, Jupiter's gravitational field ensured that no large bodies could form in a 200 million kilometre wide corridor.

The result was the Main Asteroid Belt with its unfinished planets - including Vesta, which is thought to have melted briefly after its formation but has not changed chemically since its early cooling. The Dawn spacecraft is therefore visiting a celestial body that will provide an insight into the Solar System's past for the very first time.

"On the dynamic Earth, all traces of the early days of the Solar System have disappeared, the Moon is younger, and Mars is too weathered to draw any conclusions," explains Jaumann. "But Vesta offers us the key to obtaining this knowledge."

Source: Space Mart.
Link: http://www.spacemart.com/reports/Vesta_an_asteroid_full_of_surprises_999.html.