Some 10 kg (22 lb) of the Moon rocks have been used in hundreds of experiments performed by both NASA researchers and planetary scientists at research institutions unaffiliated with NASA. These experiments have confirmed the age and origin of the rocks as lunar, and were used to identify lunar meteorites collected later from Antarctica.[37] The oldest Moon rocks are up to 4.5 billion years old,[36] making them 200 million years older than the oldest Earth rocks, which are from the Hadean eon and dated 3.8 to 4.3 billion years ago. The rocks returned by Apollo are very close in composition to the samples returned by the independent Soviet Luna programme.[38][39] A rock brought back by Apollo 17 was dated to be 4.417 billion years old, with a margin of error of plus or minus 6 million years. The test was done by a group of researchers headed by Alexander Nemchin at Curtin University of Technology in Bentley, Australia.[40]
