Stardust looks down on Moon's north pole
Posted: January 19, 2001
NASA's Stardust spacecraft successfully flew by the Earth on Monday to use the planet's gravity to change its orbit relative to the Sun, enabling the probe to widen its orbit and intercept the Comet Wild 2 in 2004.
Seventeen hours after the 11:14 GMT (6:14 a.m. EST) Earth flyby, the spacecraft flew over the moon at a distance of about 108,000 km and took 23 images to be used to perform photometric and geometric calibrations of the camera. One of these images is shown here and was taken on Tuesday at 0401:06 GMT (11:01:06 p.m. EST Monday). The image was taken through a narrow band blue filter centered at 513.2 nm with a 12 nm Full Width Half Maximum (FWHM) and using a 45 ms exposure.
The spacecraft was near the north pole of the moon at a latitude of 81 deg and a longitude of 118 deg west. The direction to the Earth is toward the right and the direction to the Sun, in the lunar equator and at a longitude of 78 deg west, is toward the bottom of the image. The lunar mare on the Earth facing side is seen dominating the right half of the image with the bright crater Aristarchus in Oceanus Procellarum near the limb.
Since the picture was composed of over 2,000 shades of gray, many more than the human eye can detect, the Stardust imaging team reduced the image to only about 100 shades of gray, enhancing the contrast between black and white. The image resolves about 7 kilometers (over 4 miles) per pixel across a 3,500-kilometer (2,200-mile) moon.
The picture shows the kind of detail the team expects to get when the camera flies by Comet Wild 2 in January 2004. Stardust's images of the comet's surface are expected to be 10 times better than any previous picture of comet nuclei. Stardust's camera, which will be used to navigate the spacecraft to the comet, will also take pictures with a 200-millimeter (8-inch) lens.
"We will see the size and shape of the comet and be able to detect small craters, variations in the brightness, dirty dusty areas, and newly iced surfaces," said Tom Duxbury, manager of the Stardust project at NASA's Jet Propulsion Laboratory, Pasadena, Calif. Stardust will also collect dust from the comet to return to Earth for study in laboratories.
Stardust, a part of NASA's Discovery Program of low-cost, highly focused science missions, is managed by the Jet Propulsion Laboratory (JPL), Pasadena, CA, for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology, Pasadena.