2011年7月26日星期二

Vesta rock turns to Dawn probe

July 22, 2011, updated at 10: 40 UTC Jonathan Amos, BBC News Science correspondent Vesta over asteroid Vesta in the southern polar region, seen from a distance of about 10,500 km the giant asteroid Vesta is revealing more than himself for the U.S. Space Agency (Nasa) mission Dawn.

The probe has been roofed over return more images since it entered into orbit around the rock around km 530 on July 17.

Dawn led the most recent batch was traveling from the side of the day with night of Vesta.

Different lighting conditions provide scientists with information about the various characteristics of surface pockmarked rock.

As Dawn surrounds his destination, so that the asteroid itself rotate on its axis. Rock rotates once every five hours and 20 minutes.

Dawn will spend a year studying at Vesta before moving on to the largest object in the asteroid belt between Mars and Jupiter - the dwarf planet Ceres.

Already, however, much to excite those interested in small planetary bodies in the Solar System.

Dawn principal investigator says has been surprised by the number and size of the craters of Vesta - there are a lot more than them and they are large he expected before the established mission.

In a tantalizing trailer screenshots but to be released, Professor Chris Russell, the University of California in Los Angeles said to the BBC this week: "the surface is much more colorful;" [colors are deeper than they are on the Moon].

"[The Moon is rather bland in comparison with the surface of Vesta]."

"It was my first surprise when we started to take some pictures of color." There are regions orange and blue. "The colours are deeper I've seen before in cometary bodies and lunar type."

We should start to see some of these photos in color in the next week.

Dawn

Asteroids are fascinating for what can tell us about the early days of the Solar System.

Wandering rocks are often described as the rubble which was left with after the suitable planets formed.

The 950 km around Ceres and Vesta are both evolved bodies - that is, objects that heating and began to separate into different layers.

In the case of Vesta, this process became quite advanced. You probably have a metal core and scientists expect to see the evidence in its latest high temperature surface and perhaps even ancient lava.

On the other hand, Ceres is far less dense, indicating that he maintains large quantities of water. Scientists suspect could be in a band icy hidden under a dusty surface.

The images we have seen so far of Vesta from dawn framing camera system that was developed and built under the direction of the Max Planck Institute for the investigation of the Solar system in Katlenburg-Lindau, Germany.

VestaThis image was acquired last weekend. Here the distance to Vesta is about 15,000 km Jonathan.Amos-INTERNET@bbc.co.uk

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