DAWN's Science At Vesta and Ceres

Data
Operations

Data

Asteroids began as minor planets in 1801 as Giuseppe Piazzi discovered Ceres. Further similar bodies were found and their number quickly amounted to several hundred by 19th century's end. Most of these minor planets are located between Mars and Jupiter orbits in what is called the asteroid belt. Both terms "minor planet" and "asteroid" are similar when used about these bodies. Asteroids comes in a variety, with some rubble piles of loosely held gravel or others mostly made of iron and all sorts in-between. Asteroids are rotating on themselves on the order of days or hours as they are very cold or hundreds of degrees below zero. Most asteroids are under 210 mi wide (340 km)and the vast majority 60-mile (100-kilometer)-wide or smaller. Largest and better known are Ceres, Vesta, Pallas, and Juno. The interest of the DAWN mission is to characterize whether Vesta and Ceres have endured a differentiation process which would singularize them from most rubble piles in the asteroid belt

Astronomers now think that Vesta, as it is so much larger than the other asteroids in the Asteroid Belt, likely is to be considered a evolved object as it looks like it is featuring a differentiated, layered structure (core, mantle and crust) which makes it more like terrestrials planets like the Earth or Mars. Like a planet, Vesta had sufficient radioactive material inside when it coalesced, releasing heat that melted rock allowing the 'differentiation' process. Heavier rocks sank like a core and lighter ones formed a crust. Vesta is now considered a protoplanet or a celestial body that almost formed into a planet but somehow never fully developed via successive mergers with other objects, which might have had to do with the nearby presence of Jupiter which gravity disturbed the orbits of objects

Ceres, as far as it is concerned, is now termed a 'dwarf planet' by the International Astronomical Union like Pluto and Eris, a body in the Kuiper Belt, and is about 590 mi wide (960 km). Ceres is the second most massive body in the Asteroid Belt and representing almost one third of the total mass of it. One day on Ceres lasts 9 hours as the asteroid is nearly round is shape. The interior of Ceres might have been differentiated -layered- like those of terrestrial planets. It might feature a rocky inner core, a icy mantle, and a thin, dusty outer crust. Ceres is featuring too a bright spot, brighter than its surroundings yet still very dark, and with a feeble albedo. That spot is remaining a mystery. Vesta may not be classified a dwarf planet as it is not quite large enough

Operations

Results Returned From Vesta
Results Returned From Ceres

Results Returned From Vesta

Vesta was the first target of DAWN in the asteroid belt. check DAWN results returned from Vesta

Results Returned From Ceres

Ensued Ceres. check DAWN results returned from Ceres