A pair of NASA satellites will be ringing in the New Year (and ringing around the Moon) this weekend. The space agency's Grail spacecraft were launched in September and, following a slow spiral, are expected to go into the Moon's orbit sometime this weekend. Their approach will bring them close to the Moon's south pole; that's when each satellite is expected to execute a roughly 40-minute engine burn to take up an elliptical orbit.
NASA scientists are hoping that new data from the satellites will solve a number of mysteries, such as why the Moon's near and far sides look so different.
"Grail will improve our knowledge of the Moon's near-side gravity by more than 100 times over what was previously known, and by more than 1,000 times over what was known on the far side," said Dr. Maria Zuber from the Massachusetts Institute of Technology.
With a gravity map indicating the surface highs and lows, NASA officials said scientists should be able to deduce the Moon's probable internal structure and composition. Grail's mapping phase will last for 82 days until early June. That's when the Moon goes into a shadow eclipse, behind the Earth.