Apollo astronauts brought home nearly 850 pounds of rocks and soil from the moon. Those samples forced scientists to throw out much of what they thought they knew about the moon, and the collection continues to be a staple of lunar research.
“They tend to be rocks very similar to Earth rocks, shockingly enough,” Samuel Lawrence, lead scientist for lunar exploration at NASA's Johnson Space Center. “That makes sense, when you think about it, because the earth and moon were formed at the same time 4.4-ish billion years ago and we're fairly convinced that they were once part of the same planet at one point.”
But that wasn’t the thinking when American astronauts first headed to the moon. At that point, some thought that the moon was an asteroid that happened to come close enough to Earth to get pulled into orbit by Earth’s gravity.
As soon as the Apollo astronauts landed on the moon, it became clear that many previous ideas were wrong.
“There is a famous story where a famous scientist who is very well regarded and won a Nobel Prize was watching the first moon landing,” Lawrence said, “and he was getting very angry, because the astronauts were more or less proving his theories wrong in real time.”
The samples that Apollo astronauts brought home revolutionized our understanding of not only the moon, but the early history of Earth and our solar system.
As technology has improved, the collection has continued to reveal surprising, new information, like the fact that there is water trapped in lunar rocks and soil.
Now, with the upcoming 50th anniversary of the Apollo 11 moon landing, NASA is releasing three previously unstudied samples for the research community.
They’re also looking ahead to what could be learned from future lunar missions.
“We only landed on the Moon six times,” Lawrence explained. “The Apollo astronauts only directly explored an area roughly the size of a suburban shopping mall in total.”
That’s pretty small, given that the total surface area of the moon is similar to the continent of Africa. And those six landing spots aren’t representative of the rest of the moon.
“If you were some visitor from outer space, and you just landed in the Grand Canyon and you tried to say ‘Oh, everywhere on earth is exactly like this,’ you'd be wrong,” said Lawrence.
Lawrence says that returning to the moon, with both humans and robots, would yield even more knowledge and could be an important step toward sustainable exploration of other planets.