Fabulous Fabia from HAMO

Above are two images of Vesta's crater Fabia (bottom right) and surrounding area. The image at left is a Dawn FC (framing camera) image showing the apparent surface brightness The image at right is overlain with color-coded based on surface topography. Image Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA


Wait! I know what you're thinking and no, the title is not the name of a Vegas show dancer. It is actually a brief description for a northern hemisphere crater on asteroid Vesta which was imaged during NASA's Dawn mission phase known as the High Altitude Mapping Orbit (HAMO). You see? Now you understand why I went with the, briefer, Variety-style title.


As noted, above are two images of Vesta's crater Fabia. The left-hand image is a Dawn FC (framing camera) image, which shows the apparent brightness of the surface. The right-hand image is based on this apparent brightness image, which has had a color-coded height representation of the topography overlain onto it. The topography is calculated from a set of images that were observed from different viewing directions, which allows stereo reconstruction. The various colors correspond to the height of the area. The white and red areas in the topography image are the highest areas and the blue areas are the lowest areas. Fabia crater is the large crater in the bottom right part of the images, with bright material along the left side of its rim. There are many features associated with mass movement of material into the center of Fabia crater. The topography image shows that the deepest part of Fabia crater (colored yellow) is offset to the right of its center. This may be due to the mass movement or to slumping that occurred in this crater. This region of Vesta is reasonably heavily cratered and there are many other craters visible in the images.


The imaged surface is located in Vesta’s Numisia quadrangle, in Vesta’s northern hemisphere. Dawn obtained the apparent brightness image with its framing camera on October 24, 2011. This image was taken through the camera’s clear filter. The distance to the surface of Vesta is 700 kilometers (435 miles) and the image has a resolution of about 70 meters (230 feet) per pixel. As noted earlier, this image was acquired during the HAMO (high-altitude mapping orbit) phase of the mission. These images are lambert-azimuthalmap projected.


At the end of April, NASA's Dawn spacecraft and mission team successfully completed nearly five months of low-altitude study of Vesta, orbiting at an average altitude of 210 kilometers (130 miles). 


Since June 15th, Dawn has been in its final major science data-gathering phase at Vesta, called high-altitude mapping orbit 2 (HAMO2). Observations obtained from this orbit will provide a companion set of data and images to those obtained during HAMO. A key difference in this phase will be the angle of the sunlight hitting Vesta. The new angle illuminates more of the northern regions that were missed in previous mapping. The principal science observations planned in this new orbit will be obtained with the framing camera and the visible and infrared mapping spectrometer.


Following this final science data gathering phase, Dawn will then spend almost five weeks spiraling out from the giant asteroid to the point at which Vesta will lose its gravitational hold on the spacecraft. That departure day is expected to be around August 26 (my birthday). Dawn will turn to view Vesta as it leaves and acquire more data. Then, Dawn will set its sights on the dwarf planet Ceres, and begin a two-and-a-half year journey to investigate the largest body in the main asteroid belt. Dawn will enter orbit around Ceres in 2015.


And now, the mission particulars...


The Dawn mission to Vesta and Ceres is managed by the Jet Propulsion Laboratory (JPL), a division of the California Institute of Technology in Pasadena, for NASA's Science Mission Directorate, Washington D.C. UCLA is responsible for overall Dawn mission science. Dawn is a project of the directorate's Discovery Program, managed by NASA's Marshall Space Flight Center in Huntsville, Alabama. Orbital Sciences Corporation (OSC) 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. The Dawn framing cameras were developed and built under the leadership of the Max Planck Institute for Solar System Research, Katlenburg-Lindau, Germany, with significant contributions by DLR German Aerospace Center, Institute of Planetary Research, Berlin, and in coordination with the Institute of Computer and Communication Network Engineering, Braunschweig. The Framing Camera project is funded by the Max Planck Society, DLR, and NASA/JPL. The California Institute of Technology in Pasadena manages JPL for NASA.


To view the new Vesta images and for more information about Dawn, visit: www.nasa.gov/dawn and dawn.jpl.nasa.gov .


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