Described by Galileo Galilei as "a most beautiful sight to behold" and, contradicting many philosophers of his time, as "uneven, full of hollows and protruberances" Earth's natural satellite has always been an object of wonder and interest. Since Galileo's time, continually improved telescopes, and modern exploratory space flights, have revealed information about the nature of the Moon that is fascinating both to laymen and scientists.

We now know for example that the Moon is like, but also not like, Earth. It has many of the same elements in its core, mantle, and crust but does not have air, nor oceans. There are no plants and people have never lived there although a few lucky ones have visited. Between 1964 and 1972 NASA sent 22 scientific missions to the Moon. But, despite these explorations, much of the Moon remained a mystery and scientists have been anxious to return to the Moon to prospect for additional information

So, on January 6, 1998, Lunar Prospector, NASA's first dedicated lunar mission in 25 years blasted off to the Moon aboard a three-stage rocket called Athena II. After a four-day journey to the Moon and entry into lunar polar orbit, the unmanned, tiny, drum-shaped spacecraft successfully started its eighteen-month mission circling the moon once every 118 minutes first at a distance of 63 miles and later only 6 miles above the Moon's surface.

The Prospector's main job was to map lunar resources, gravity, magnetic fields, and gases released from the lunar interior. At the end of its mission, in July 1999, the Prospector was deliberately crashed into the Lunar surface while astronomers around the world watched carefully with sensitive spectrometers to detect the effects of the impact.

1) What did the astronomers hope to detect?
2) What led them to think this might be a possibility?