lundi 20 avril 2015

Ceres' Bright Spots Come Back Into View












NASA - Dawn Mission patch.

April 20, 2015


Image above: This image shows the northern terrain on the sunlit side of dwarf planet Ceres as seen by NASA's Dawn spacecraft on April 14 and 15, 2015. Image Credits: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA.

The two brightest spots on dwarf planet Ceres, which have fascinated scientists for months, are back in view in the newest images from NASA's Dawn spacecraft. Dawn took these images on April 14 and 15 from a vantage point 14,000 miles (22,000 kilometers) above Ceres’ north pole.

The images show the brightest spot and its companion clearly standing out against their darker surroundings, but their composition and sources are still unknown. Scientists also see other interesting features, including heavy cratering. As Dawn gets closer to Ceres, surface features will continue to emerge at increasingly better resolution.

Dawn has now finished delivering the images that have helped mission planners maneuver the spacecraft to its first science orbit and prepare for subsequent observations. All of the approach operations have executed flawlessly and kept Dawn on course and on schedule. Beginning April 23, Dawn will spend about three weeks in a near-circular orbit around Ceres, taking observations from 8,400 miles (13,500 kilometers) above the surface. On May 9, Dawn will begin to make its way to lower orbits to improve the view and provide higher-resolution observations.


Animation above: his animated sequence of images from NASA's Dawn spacecraft shows northern terrain on the sunlit side of dwarf planet Ceres. Dawn took these images on April 14 and 15 from a vantage point 14,000 miles (22,000 kilometers) above Ceres' northern hemisphere. The spacecraft was settling into its first circular orbit, called RC3 (for "rotation characterization 3"), which it will begin on April 23.

The bright feature called "spot 5" by the Dawn science team -- actually two bright spots close together -- rotates into view at right in the last few frames. Image Credits: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA.

"The approach imaging campaign has completed successfully by giving us a preliminary, tantalizing view of the world Dawn is about to start exploring in detail. It has allowed us to start asking some new and intriguing questions," said Marc Rayman, Dawn's mission director and chief engineer, based at NASA's Jet Propulsion Laboratory, Pasadena, California.

Dawn spacecraft heading Ceres. Image Credit: NASA

On March 6, Dawn became the first spacecraft to orbit a dwarf planet, and the first to orbit two extraterrestrial targets. Scientists will be comparing Ceres to giant asteroid Vesta, which Dawn studied from 2011 to 2012, in order to gain insights about the formation of our solar system. Both Vesta and Ceres, located in the main asteroid belt between Mars and Jupiter, were on their way to becoming planets before their development was interrupted.

Dawn's mission is managed by JPL for NASA's Science Mission Directorate in Washington. Dawn is a project of the directorate's Discovery Program, managed by NASA's Marshall Space Flight Center in Huntsville, Alabama. UCLA is responsible for overall Dawn mission science. Orbital ATK, Inc., in Dulles, Virginia, designed and built the spacecraft. The German Aerospace Center, the Max Planck Institute for Solar System Research, the Italian Space Agency and the Italian National Astrophysical Institute are international partners on the mission team. For a complete list of acknowledgements, visit http://dawn.jpl.nasa.gov/mission

For more information about Dawn, visit: http://dawn.jpl.nasa.gov

Image (mentioned), Text, Credits: NASA/JPL/Elizabeth Landau.

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