New research by a team of scientists from the U.S., Denmark and France suggest that the moon may be 200 million years younger than was previously thought. Using a new method to analyze rock samples, that were brought back to Earth in 1972 by Apollo 16 astronauts, the scientists have placed its age at about 4.36 billion years.
The prevailing hypothesis is that the moon was created after a large planet-like object collided with the still-molten Earth about 4.5 billion years ago. The energy of the impact from the collision was so great that molten material was ejected into space forming the moon. The moon was thought to have been covered in a sea of magma and as the magma cooled it solidified into different mineral components. The less dense minerals floated to the top first, forming the Moon’s crust. These crustal rock samples have been used to determine the point at which the moon solidified.
To obtain the Moon’s new age the scientific team developed new techniques to analyze isotopes of the elements lead and neodymium which is found in the moon rock. This type of rock, which makes up a large part of the luminescent splotches we see on its surface, is thought to be the oldest, and previous testing methods used made it difficult to obtain precise data.
“It has pretty profound implications,” said Lars Borg, a planetary geologist at the Lawrence Livermore National Laboratory in California, who co-authored the paper, which was published online Wednesday in the journal Nature. The new age, which is among the most precise measurements found so far, could either render a lot of previous research on the moon’s age invalid, Borg said, or change our understanding of how the moon was formed.