Deep Impact Spots Quarry
Sixty-nine days before it gets up-close-and-personal with a comet, NASA's Deep Impact spacecraft successfully photographed its quarry, comet Tempel 1, at a distance of 39.7 million miles. The image, taken on April 25, 2005, is the first of many comet portraits Deep Impact will take leading up to its historic comet encounter on July 4.
Taken on Monday, April 25, this is a composite of 30 images taken with the MRI camera. This improved the SNR (signal-to-noise ratio) and allowed cosmic rays to be removed. By stretching the image from minimum to 20% of max (adjusting the brightness and contrast so to speak), you can then see the significant coma around the nucleus. At the distance of the comet, each pixel is ~600 km across, so the coma is pretty extensive. This was a great milestone for the project. Although many images of the comet have been taken by Earth-based observers, including amateurs (see the Mission, STSP and Amateur galleries), this was the first one taken by the spacecraft. The spacecraft will start imaging the comet on a regular basis in about 10 days.
In this orientation, North is at the bottom and East is on the right.
Date: 25 April 2005