4.35 billion years old
There are currently two spacecraft orbiting the moon, one from Japan and one from China. India is planning an orbiter and a lander on the moon next April. The US will follow with a series of missions starting with an orbiter next year and with an intention to have permanent bases on the moon by 2020.
Dr Mahesh Anand has co-authored a paper, published this week in Nature, that dates basaltic volcanic activity on the moon to 4.35 billion years ago. Dr Anand, along with Dr Kentaro Terada of Hiroshima University, Japan and colleagues came to this conclusion after dating minerals in a lunar meteorite dubbed Kalahari 009 — some were associated with fragments of crystallized magma from the earliest eruptions on the Moon's vast plains. Other lunar rock samples collected during Apollo missions are the result of more recent eruptions.