29 March 2011: 29 March 1807 German astronomer Heinrich Wilhelm Olbers, Vesta discovered a needle of light in the sky. Two fascinating world hundred and four years later, prepared these start dawn spacecraft NASA orbiting, scientists now how special this world is, although there are some discussions about, know how to classify it.
Many astronomers call asteroid Vesta because it is located in the main asteroid belt between Mars and Jupiter. Vesta is however not typical member, that orbit debris patch. The vast majority of the objects of the main belt are lightweights, 100 km wide or less, compared to Vesta, which is a 530 kilometer-wide behemoth.
"I don't think should be called Vesta, an asteroid", said Tom McCord, a dawn co-investigator was based on the bear fight Institute, Winthrop, Washington "not only Vesta is so much greater, but it is an evolved object, unlike most of the things we call asteroids."
The layered structure of Vesta (core, mantle, and crust) said the key feature as the other asteroid Vesta more like planets such as Earth, Venus and Mars makes McCord. Like the planet, Vesta had sufficient radioactive material in when it fused, heat melted the rocks release and enabled lighter layers to float to the outside. Scientists call this differentiation process.
McCord and colleagues were the first to discover that Vesta was probably distinguished when basalt special detectors on their telescopes 1972 picked up the signature. This meant that the body had to have melted at a time.
Vesta is officially a "minor planet"-a Panel, that the Sun but is not a proper planet or comet. But there is more than 540,000 minor planets in our solar system, is just the name Vesta be not much difference. The dwarf planet - including Dawn's second goal, Ceres--are another category, but Vesta you be not as one of those. For one thing, Vesta is not large enough.
Dawn scientists prefer to think of as a Protoplanet Vesta, because it is a dense body, is layered, the the Sun and began in the same way as mercury, Venus, Earth and Mars, but somehow never fully developed. In the swinging early history of the solar system, Vesta size objects was planet by merging with other objects. But Vesta never found a partner, passed during the big dance and the critical time. It can interfere with the nearby presence of Jupiter, the neighborhood of the gravitational superpower, which have had to do the orbits of objects and the partner in hardware.
Other space rocks have collided with Vesta and bits of it behind. They were called in the asteroid belt Vestoids, and even hundreds of meteorites that landed on Earth. But Vesta never large collided enough with something, to disrupt it, and it has been preserved. Vesta is thus a time capsule from this earlier period.
"This gritty little Protoplanet bombardment in the asteroid belt has 4.5 billion years, so that its surface may survive the oldest surface of the planet in the solar system", Christopher Russell, Dawn's principal investigator, said based on the UCLA. "Study Vesta, a much better story of the solar system write turbulent youth we can."
Dawn's scientists and engineers have to study a master plan, developed this special features of Vesta. When Dawn arrives in July at the Vesta, is the South Pole in full sun, the scientists a clear view of a huge crater at the South Pole. This crater can the layer cake of materials in Vesta reveal, who will tell us how the body designed for education. The orbit design allows dawn to progress on the 12-month visit map new terrain as the seasons. Many measurements, & a. high resolution data of surface, topography and texture make the probe. The probe will measure more the tug of the Vesta's gravity experience on its internal structure.
"Dawn's engines are ion carry us gently in the direction of Vesta, and the probe is always ready for his big year of exploration,", said Marc Rayman, Dawn's chief engineer at the Jet Propulsion Laboratory of NASA, Pasadena, California "we have our mission, the this opportunity", the exciting secrets of this uncharted optimally ausgelegtexotische the world. "
Production editor: Dr. Tony Phillips | Credit: Science@NASA
Dawn--mission homepage
Credits: The dawn mission to Vesta and Ceres is Propulsion Laboratory managed by the Jet, a division of the California Institute of technology in Pasadena, California, for NASA's Science Mission Directorate, Washington. The dawn, the mission part of the discovery programme managed by the NASA Marshall Space Flight Center in Huntsville, Ala. UCLA is is responsible for overall dawn mission science. Orbital Sciences Corporation in Dulles, Virginia, designed and built the spacecraft dawn. The German Center for air and space, the Max Planck Society, the Italian Space Agency and Italian national Astrophysical Institute are part of the team mission.
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