25. November 2015

First at­las of dwarf plan­et Ceres pub­lished

Polar regions on the dwarf planet Ceres
Po­lar re­gions on the dwarf plan­et Ceres
Image 1/3, Credit: DLR (CC-BY 3.0)

Polar regions on the dwarf planet Ceres

These two im­ages show the North Pole (left) and the South Pole (right) of the dwarf plan­et Ceres in a scale of 1:2,000,000. Plan­e­tary re­searchers from the Ger­man Aerospace Cen­ter (Deutsches Zen­trum für Luft- und Raum­fahrt; DLR) used cam­era im­ages ac­quired by the Dawn or­biter at a dis­tance of 4400 kilo­me­tres from Ceres to pro­duce these maps.
Occator region on the dwarf planet Ceres
Oc­ca­tor re­gion on the dwarf plan­et Ceres
Image 2/3, Credit: DLR (CC-BY 3.0)

Occator region on the dwarf planet Ceres

Plan­e­tary re­searchers from the Ger­man Aerospace Cen­ter (Deutsches Zen­trum für Luft- und Raum­fahrt; DLR) used cam­era im­ages ac­quired by the Dawn or­biter at a dis­tance of 4400 kilo­me­tres from Ceres to pro­duce this map. It shows the strik­ing Oc­ca­tor crater and the un­usu­al­ly bright spots on its in­te­ri­or.
Kerwan region on the dwarf planet Ceres
Ker­wan re­gion on the dwarf plan­et Ceres
Image 3/3, Credit: DLR (CC-BY 3.0)

Kerwan region on the dwarf planet Ceres

Plan­e­tary re­searchers from the Ger­man Aerospace Cen­ter (Deutsches Zen­trum für Luft- und Raum­fahrt; DLR) used cam­era im­ages ac­quired by the Dawn or­biter at a dis­tance of 4400 kilo­me­tres from Ceres to pro­duce this map. It shows the re­gion around Ker­wan crater.

The dwarf planet Ceres measured a mere nine pixels across on an image acquired by NASA's Dawn orbiter on 1 December 2014. Since then, the planetary researchers at the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) have received thousands of images showing the dwarf planet and its unusually varied surface. The scientists have now selected 42 images acquired during the 'Survey Orbit' in June 2015, during which Dawn observed Ceres from a distance of 4400 kilometres, to produce the At­las of Ceres and Ves­ta. This is now available online. The most time-consuming task was to compute the three-dimensional elevation model, in which the DLR researchers determined the elevation of 12,000 points on Ceres.

"It was important to select images that covered the entire dwarf planet under the same illumination conditions," explains Thomas Roatsch from the DLR Institute of Planetary Research. "This allowed us to calculate a uniform, homogenous terrain model." In turn, the model was used as a basis for further processing, in which the individual images were put together to form a global mosaic of the dwarf planet. This was then used to produce the various maps contained in the atlas. Kait crater, named after an Asian crop goddess, was selected as the reference crater for the prime meridian.

The team at DLR is responsible for using the camera data to produce maps and elevation models throughout the entire mission. The images used for the first atlas have a resolution of 400 metres per pixel. The images acquired during lower orbits will serve as a basis to refine the terrain model and to create more detailed atlases. "We are already working with the data from the next orbit, which Dawn reached in August 2015." During this High Altitude Mapping Orbit (HAMO), the spacecraft and its camera system reached a position just 1470 kilometres above the dwarf planet. Dawn is not sending any images at the moment, as it is on its way to the mission's lowest orbit – the Low Altitude Mapping Orbit (LAMO). Once it arrives at its final destination, the camera will look down on the surface of Ceres from an altitude of just 375 kilometres.

Two very different celestial bodies

Dawn provides planetary researchers with the first opportunity to analyse two celestial bodies in the asteroid belt between Mars and Jupiter during just one mission, and so look back at the origin of the Solar System. The orbiter circled and analysed the asteroid Vesta from July 2011 to September 2012. Dawn has now orbited Ceres – in 2006 reclassified a dwarf planet and not an asteroid – since March 2015. "Dawn allows us to visit two entirely different celestial bodies for the first time on a single mission. Vesta is one of the dry asteroids, while Ceres is wet and may even have an ocean beneath its crust," says Ralf Jaumann, a DLR planetary researcher and member of the camera team on the NASA mission.

Vesta surprised the scientists with unusual impact craters, a mountain three times the height of Everest, valleys and canyons. But Ceres seems to be promising as well; among other things, the dwarf planet has crater walls steeper than the north face of the Eiger, which tower almost 2000 metres above their surroundings. The bright spots that had already been identified at a larger distance continue to provoke debate among the scientists. "Ceres gives us many fascinating puzzles, and exhibits phenomena that we have not seen anywhere else in our Solar System."

The mission

The Dawn mission to Vesta and Ceres is managed by NASA's Jet Propulsion Laboratory (JPL) in Pasadena, which is a division of the California Institute of Technology, for NASA's Science Mission Directorate in Washington DC. The University of California, Los Angeles, is responsible for overall Dawn mission science. The camera system on the spacecraft was developed and built under the leadership of the Max Planck Institute for Solar System Research in Göttingen, Germany, with significant contributions from the German Aerospace Center (DLR) To the In­sti­tute's web­site in Berlin and the Institute of Computer and Communication Network Engineering in Braunschweig. The Framing Camera project is funded by the Max Planck Society, DLR, and NASA/JPL.

Contact
  • Manuela Braun
    Com­mu­ni­ca­tion
    Ger­man Aerospace Cen­ter (DLR)
    Pro­gramme and Strat­e­gy, Space Re­search and Tech­nol­o­gy
    Telephone: +49 2203 601-3882
    Fax: +49 2203 601-3249
    Hansestraße 115
    51149 Cologne
    Contact
  • Prof.Dr. Ralf Jaumann
    Freie Uni­ver­sität Berlin
    In­sti­tute of Ge­o­log­i­cal Sci­ences
    Plan­e­tary Sci­ences and Re­mote Sens­ing
    Telephone: +49-172-2355864
    Malteserstr. 74-100
    12249 Berlin
    Contact
  • Thomas Roatsch
    Ger­man Aerospace Cen­ter (DLR)
    In­sti­tute of Plan­e­tary Re­search
    Telephone: +49 30 67055-339
    Fax: +49 30 67055-402
    Rutherfordstraße 2
    12489 Berlin
    Contact
Related news

Main menu