Stellar Calibration, HiRISE!
As part of a calibration test conducted on December 14, 2005, the HiRISE camera on Mars Reconnaissance Orbiter snapped this image of part of Jewel Box, an open star cluster. Jewel Box was so named by Sir John Herschel because of the variety of star colors in the cluster, including the large red giant seen near the bottom of this image.
"The images we've acquired of stars and the Moon have been very sharp," said Dr. Alfred McEwen, the camera's principal investigator. "The camera and spacecraft work great, so we are really looking forward to imaging Mars."
HiRISE can image in three colors: green, red, and near-infrared, so the colors are not exactly as we see them with our eyes. Jewel Box, also called Kappa Crucis, is about 10 million years old, so it is much younger than our Sun at 4600 million years old. The Jewel Box cluster lies about 7,500 light years away, so the light we see today left the stars at the time of Earth's Neolithic ages, when farming was first being practiced. The image shown here is a small portion of the full image, which is 20,000 x 35,000 pixels or 700 mega-pixels.