The Secret to How Water Made It to Earth Finally Revealed in New Asteroid Experiment
The Holy Grail of astrobiology is still discovering liquid water on an alien planet, but scientists still aren't sure where Earth got its water.
One theory is that Earth received water from asteroid impacts, a bit similar to the panspermia hypothesis, which suggests bacteria hitched a ride on an asteroid and survived the collision with a young Earth.
We still don't have a definitive answer on the panspermia theory, but a new study published in Science Advances shows that asteroids do have the capacity to dump a lot of water during a high-speed impact with rock similar to Earth's.
Even better, Earth-like rocks seem to hold onto that water.
The study details an experiment involving NASA's Ames Vertical Gun Range, where model asteroids made of antigorite were loaded into a cannon and fired at a large chunk of dry pumice, which was supposed to simulate the conditions of early Earth.
The experiment took place in a vacuum and created a lot of debris, including formations called breccia, which are made of broken chunks of rock.
After examining the bits of rock that came from the impact, researchers found that they still had around 30 percent of the water content of the original mini-asteroids.
This means that water can, in theory, survive the explosive impact that comes from its host asteroid hitting another planet and find its way onto the planet itself.
According to the abstract of the study:
"Entrapment of water within impact glasses and melt-bearing breccias is, therefore, a plausible source of hydration features associated with craters on the Moon and elsewhere in the solar system and likely contributed to the early accretion of water during planet formation."
In layman's terms, this experiment not only provides a potential model for how Earth gained its water, but how other planets might, too.
With this in mind, maybe impact craters will be the next guidepost for finding habitable planets...or extraterrestrial life.