A research collaboration involving scientists from the UK, Canada, Sweden, and Australia has analyzed an ancient rock sample brought from the Moon to Earth by the Apollo 17 astronauts more than 50 years ago. By using modern techniques, which were simply not available at the time the samples were originally collected, the team was able to determine the rock sample’s age, from which crater it came, and its geological trajectory. It turns out that this rock is very, very old -- around 4.2 billion years old. That’s only about 350 million years younger than the entire Solar System.