A Wild Comet Like No Other A Wild Comet Like No Other 1 A new arrival to the inner solar system is the comet Wild 2. Although the comet has proven to be very different, in fact wild, it did not get its name because it is wild. It was named after Paul Wild, the scientist who discovered it on January 6, 1978, during its first passage near Earth. 2 This comet formed in an area beyond Neptune, 4.5 billion years ago, just after the sun came into existence. Until September 10, 1974, it orbited the sun between Jupiter and Uranus. On that date Wild 2 passed within 557,000 miles of Jupiter, the largest planet, which brought it into the inner solar system for the first time. This new orbit carried it closer to the sun than ever. It now approaches the sun just inside the orbit of Mars. 3 NASA's Stardust spacecraft, which was launched in 1999, allowed scientists to see and study Wild 2. The Stardust examined Wild 2 in a close flyby on January 2, 2004, when it flew just 147 miles from the comet. Only two other comets have been seen up close, both appearing fairly smooth and not very heavily cratered. Scientists were quite sure they knew what they would discover about this comet also. 4 Scientists thought Wild 2 would be a dirty, black, fluffy ball. Were they ever surprised! Instead, results from the Stardust flyby show the Wild 2 to have a rigid surface that supports towering cliffs and peaks 328 feet tall. 5 On Wild 2, there are plunging pits and craters 492 feet deep. In addition, scientists have discovered two different types of craters on the comet. One type has pits that are rimmed with jagged material ejected from the crater. The other type appears to have flat floors and straight sides. Two large craters of this type are shaped like footprints. The largest one, named Left Foot, is two-thirds of a mile in diameter. The entire comet is only three miles across. Photographs taken by the Stardust have allowed scientists to develop a map of Wild 2 that shows only large craters like Left Foot. 6 Scientists were also su