31-12-11 First of NASA Grail gravity twins enters Moon orbit

NASA has succeeded in putting the first of two gravity mapping satellites in orbit around the Moon.The Grail-A spacecraft fired its main engine late on Saturday (GMT) to slow itself sufficiently to take up an elliptical path around the lunar body.Its twin,Grail-B,will attempt exactly the same manoeuvre on Sunday.Together,the satellites will make measurements that are expected to give scientists remarkable new insights into the internal structure of the Moon.This new data should clarify ideas about the Moons formation and resolve many questions,such as why its near and far sides look so different.Lead scientist Dr Maria Zuber is hoping for some dramatic discoveries."My resolution for the new year is to unlock lunar mysteries and understand how the Moon,Earth and other rocky planets evolved," the Massachusetts Institute of Technology (MIT) researcher said."Now,with Grail-A successfully placed in orbit around the Moon,we are one step closer to achieving that goal." The duo were launched from Cape Canaveral,Florida,last September,and took a long spiral out to their destination.This weekends approach to the Moon was designed to bring them in over the south pole.