When the astronauts on the Apollo 14 mission returned to Earth with samples from the moon’s surface, they were bringing back a part of Earth’s history. A “moon rock” that the Apollo 14 astronauts collected was expected to have been launched from Earth after a large impact on the Earth’s surface.
NASA scientists believe that a comet or asteroid caused the collision, which launched the rock into space. The scientists were able to tell that the rock originated from Earth by observing the quartz and zircon inside of it. Another reason that the researchers believe that the rock was from Earth is that the rock appeared to have formed at temperatures that are in relation with the estimated temperature on Earth around 5 million years ago. There are also slight traces of oxygen in the rock, which also corresponds with rocks formed on Earth.
However, it stumped some researchers when they tried to uncover the way the asteroid was jettisoned from Earth. After all, if the rock was from Earth, it would have been deep in the Earth and it would be almost impossible to have been launched all the way to the Moon. Recently, NASA scientists discovered how it could've happened. The way that the rock was launched was supposedly from multiple asteroid or comet strikes. Eventually, the craters from the strikes left the rock vulnerable to the final strike from a large asteroid or comet, which had enough kinetic energy to launch the rock out of the atmosphere onto the surface of the Moon.