Last night the Stardust-NExT spacecraft successfully returned new images of the periodic comet 9P/Tempel, showing significant changes on the comet's surface as a result of its orbit around the Sun, and imaging a new territory on the comet for the first time. Moreover the impact location of 2005 "Deep Impact" projectile was imaged and it showed for the first time the resulting crater.
The Stardust-NExT mission was intended to complete the investigation of comet 9P/Tempel initiated in 2005 by NASA's Deep Impact spacecraft. For more info about this flyby (178 kilometres at close approach), please see our previous post:
The mosaic image below shows four different views of comet Tempel 1 as seen by NASA's Stardust spacecraft (please click on each image to see a bigger version).
Below one of the close-approach images of comet 9P/Tempel
(Credit: NASA/JPL-Caltech/Cornell)These two images below shows the different views of comet Tempel 1 seen by NASA's Deep Impact spacecraft in 2005 (left) and NASA's Stardust spacecraft in 2011 (right).
This image layout below depicts changes in the surface of comet Tempel 1, observed first by NASA's Deep Impact Mission in 2005 (top right) and again by NASA's Stardust-NExT mission on Feb. 14, 2011
This pair of images below shows the before-and-after comparison of the part of comet 9P/Tempel that was hit by the impactor from NASA's Deep Impact spacecraft. The crater closely matched predictions, measuring approximately 150 metres in diameter. According to Pete Shultz of Brown University: "The crater was more subdued than perhaps we first thought, but it was the size we expected, which is consistent with the ejecta pattern we observed, and what we'd expect in an oblique, 30 degree impact. A lot of material came back down and the crater partly buried, or healed, itself. The cometary nucleus must be fragile and weak based on how subdued the crater is we see today."
Below you can see an animation showing (31 frames) the comet flyby:
The engineering telemetry showed the spacecraft flew through waves of disintegrating cometary particles, including a dozen impacts that penetrated more than one layer of its protective shielding. According to Don Brownlee, Stardust-NExT co-investigator: "The data indicate Stardust went through something similar to a B-17 bomber flying through flak in World War II. Instead of having a little stream of uniform particles coming out, they apparently came out in chunks and crumbled."
The Stardust-NExT spacecraft will continue to look at comet 9P/Tempel from afar to gain other useful information.
by Ernesto Guido