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Lunar letdown

发布时间:2019-03-07 04:01:07来源:未知点击:

By Charles Seife in Washington DC NASA’s Lunar Prospector probe went out with a bang on 31 July, slamming into a crater at the Moon’s South Pole. But unfortunately it failed to kick up the plume of debris that scientists hoped would provide definitive evidence of frozen water on the Moon. Although telescopes observing the visible spectrum saw nothing, the Lunar Prospector’s telemetry equipment indicates that the craft hit its target. And scientists still hope that detailed analysis will show that water spewed out into space. “It will take a couple of weeks to extract the signal from the noise,” says David Leckrone of NASA’s Goddard Space Flight Center near Greenbelt, Maryland. Lunar Prospector also carried the ashes of planetary scientist and comet-spotter Eugene Shoemaker, who died in 1997. NASA officials thought that it was a fitting tribute to bury him on the Moon. A second NASA spacecraft also experienced mixed fortunes last week. On 29 July, the Deep Space 1 spacecraft flew to within about 15 kilometres of asteroid 1992 KD, otherwise known as Braille. This was the closest ever approach to a planetary body without actually landing on it and was performed using the spacecraft’s unique autonomous navigation system. Unfortunately, Deep Space 1’s camera was pointing in the wrong direction at the time. “It doesn’t look too optimistic from the black-and-white photos,” admits John Watson,