Lunar meteorites are very rare rocks that scientists sometimes discover in Antarctica or deserts. Find out how a new study of the trace gases they contain has shed light on the origins of the moon and the Earth.
Ever since Galileo used one of the first telescopes to see the craters on the moon, scientists have sought to understand how we came by our huge natural satellite.
Growing up during the Space Race, I remember television documentaries explaining that the moon formed from a big chunk of the Earth. Back then, scientists speculated that this might be the reason the Pacific Ocean is so wide and deep.
That was before the Apollo astronauts brought home samples of the lunar surface. Studying those samples has led most scientists to further propose that the moon formed from a spectacular collision involving the Earth and another planet. They call this planet Theia.
One Hundred Million Times More Powerful than Dinosaur Collision
The collision with Theia would have been 100 million times more powerful than the impact that wiped out the dinosaurs. An explosion like that would vaporize a large chunk of the Earth’s crust.
Then, over time, gravity would pull the vaporized particulate together. The result, according to the most accepted hypothesis, became the largest moon in our solar system.
Not everyone agrees that the moon formed from a single, giant impact. There’s also a school of thought that a shower of smaller debris caused the moon’s formation.
Other Researchers Say Earth and Moon Formed Together
Other researchers have suggested that the Earth and the moon formed together. Other planets and their moons sometimes do that.
Even so, this wouldn’t explain why the Earth and the Moon have very different densities. As we know, the moon has much lower gravity than Earth.
Another explanation is that the moon formed on its own and then the Earth captured it. This is what happened with the…