A new study analyzing moon rocks brought back by Apollo astronauts suggests that the moon may hold a record of Earth’s earliest atmosphere, which has been lost on our own planet. The research indicates that the moon’s magnetic field existed for only the first 140 million years of its existence, allowing it to capture ions from Earth’s atmosphere 4.36 billion years ago. This discovery could provide valuable insights into the composition of Earth’s early atmosphere, a period that remains largely unknown due to the lack of preserved rocks.