The belief that asteroids were the ones to bring water to Earth isn't unheard of. It sounds like a ridiculous theory, but as a new experiment shows, it might not be that farfetched.
Researchers from Brown University have discovered, through fake asteroid impact tests, that the melted rocks from asteroids can "trap surprisingly large quantities of water." Though that information comes from simulated experiments, it's an important food for thought. If asteroids can have large quantities of water, then it's safe to imagine that planetary systems other than Earth might have water on or in them, says study author Terik Daly.
"The origin and transportation of water and volatiles is one of the big questions in planetary science," Daly said.
The findings were published in Science Advances on April 25.
The researchers used NASA's Ames Vertical Gun Range, which has been around since the 1960s and helped with studying the high-speed impacts of Project Apollo. In this new experiment, which took place in a vacuum, the researchers loaded up the gun with fake asteroids made of mineral antigorite and shot it five times faster than a bullet at a 45-degree angle at a waterless pumice volcanic rock, which is supposed to stand in for Earth.
The result? A chaotic bonanza of rock, including meteorite pieces, glasses produced from high heat, and breccias — rocks that are composed of broken fragments. All three had as much as 30 percent water left over from the asteroid.
"These experiments reveal a mechanism by which asteroids could deliver water to moons, planets and other asteroids. It's a process that started while the solar system was forming and continues to operate today."
The Origin Of Water
It remains a huge mystery just where Earth got its water from. A long-held belief alleges that water was delivered via icy comet impacts. Another says it came from the mantle, but isotopic measurements have revealed that the planet's water is similar to that in carbonaceous asteroids, suggesting that asteroids could have also been a source of water. How that got here is what boggles the minds of scientists.
The findings could have significant implications for making informed guesses as to the origin of our planet's water. The experiment shows that it's possible early Earth collided with an asteroid filled with water, which then got incorporated as Earth developed later on. Beyond Earth, this might also explain why there's water within the Moon's mantle, as previous studies have suggested that the Moon's water came from asteroids as well.
"The point is that this gives us a mechanism for how water can stick around after these asteroid impacts," said coauthor Pete Schultz.