Cassini is an unmanned spacecraft sent to the Saturn system. It is the fourth space probe to visit the ringed planet, as well as the first to enter orbit. It has been studying Saturn and its many moons since arriving there in 2004.
Tracing our Moon's changing porosity may ultimately help astronomers to track the trajectory of the invading army of a multitude of lunar impactors, that occurred during the Late Heavy Bombardment, 4 billion years ago.
A New Moon is when the moon takes its monthly promenade and reaches the phase where it comes to rest between the sun and Earth, in this position the moon's dark side is facing us making it seem 'invisible'.