The earth satellite once had a powerful magnetic field. Why has it largely disappeared now?
The last manned moon flight brought something new: Harrison “Jack” Schmitt was the first scientist on board. After the Apollo 17 lunar module touched down on the edge of Mare Serenitatis in December 1972, Schmitt and his colleague Eugene Cernan collected 111 kilograms of lunar rock. Among them were samples that the astronauts had knocked off large boulders and photographed in detail. It took decades to prove just how important this accuracy was for studying the long-lost lunar magnetic field
