NASA's Dawn spacecraft entered orbit around the dwarf planet Ceres on 6 March 2015 at 13:39 CET. In order for Dawn to be captured by Ceres' gravitational field, the spacecraft started using its ion engines from a distance of 61,000 km to slow the spacecraft down.
It is only a few more days until the Dawn spacecraft enters orbit around Ceres on 6 March 2015, marking humankind's first visit to a dwarf planet. What Ceres has disclosed to scientists so far has raised more questions than it has provided answers.
This image of the dwarf planet Ceres was acquired on 19 February 2015 by the German-built Framing Camera on board the NASA orbiter Dawn from a distance of just under 46,000 kilometres. There are several unusual bright patches on the surface of Ceres.
Only 46,000 kilometres separated the Dawn spacecraft from its destination, the dwarf planet Ceres, when its German-built Framing Camera acquired the latest images on 19 February 2015. One of the most striking features of Ceres is the multitude of different crater shapes across its surface; in addition to numerous smaller, shallow craters, the images also reveal impact basins with large mountains located at their centres.
Planetary scientists have never seen dwarf planet Ceres from this close up. The German-developed Framing Camera on board NASA's Dawn spacecraft acquired this image on 25 January 2015 from a distance of just 237,000 kilometres.
Planetary scientists at the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) may find a thick ice crust with an ocean underneath when the NASA Dawn spacecraft arrives at Ceres in March 2015. Even now, from a distance of 383,000 kilometres, the first surface features are visible.
With a diameter of nearly 1000 kilometres, it was the largest known asteroid – and yet Ceres, which was 'promoted' from asteroid to dwarf planet in 2006, is just nine pixels wide in the image acquired by the Dawn spacecraft on 1 December 2014.
On 11 May 2011, the camera on board the Dawn spacecraft acquired its first picture of the asteroid Vesta. Despite its diameter of 530 kilometres, this heavenly body appeared as no more than a white dot in the image – at that time, the spacecraft was still 975,000 kilometres away from its destination.
A giant impact crater on its south pole; deep grooves around its equator; dark material on the craters that puzzles planetary researchers; and a mountain more than twice the height of Mount Everest.
Even though it doesn’t quite qualify as a 'proper' planet, the second most massive asteroid in the Solar System, Vesta – which has a diameter of approximately 530 kilometres – exhibits numerous planetary characteristics. This is just one of the many significant results of NASA's Dawn mission, published in the journal Science on 11 May 2012. The Dawn spacecraft has been orbiting Vesta since 16 July 2011. The German Aerospace Center (DLR) is involved in the mission.