The newest paper to return out of the Japanese Space Agency’s (Jaxa) sample return mission to the asteroid Ryugu offers more evidence to support a longstanding theory about where Earth got its water — namely, from asteroids like Ryugu.
“Volatile and organic-rich C-type asteroids could have been one in all the essential sources of Earth’s water,” the research team led by Yuichi Tsuda, project manager for Jaxa’s sample return mission, wrote in a paper published Monday in Nature Astronomy.
But, they proceed, that theory relies totally on carbonaceous chondritic meteorites which have fallen to Earth: “The meteorite record is biased: only the strongest types survive atmospheric entry and are then modified by interaction with the terrestrial environment.”
Planetary scientists consider that either asteroids or comets crashing into the infant Earth were liable for providing our planet with its water. However the chemical makeup of comets doesn’t quite match what scientists would expect based on minerals found on Earth, in response to an article on the Carnegie Institution for Science website.
Scientists theorise that enormous asteroids generally known as planetesimals, that are wealthy in volatiles reminiscent of hydrogen and water stored in clays, are a greater chemical match because the source of Earth’s water. Many present-day asteroids like Ryugu could store material like that of primordial planetesimals held in a deep freeze.
The newest results of laboratory tests of fabric sampled from Ryugu and returned to Earth in December by Jaxa’s Hayabusa 2 mission confirm that Ryugu is a superb example of the fabric formed within the early Solar System, typical of the asteroids from which carbonaceous chondritic meteorites were chipped off, but without alteration by Earth’s chemistry.
“Ryugu particles are probably the most uncontaminated and unfractionated extraterrestrial materials studied to this point, and supply one of the best available match to the majority Solar System composition,” the researchers write. As an example, while carbonaceous chondritic meteorites contain the minerals ferrihydrite and sulfate, researchers didn’t find those minerals within the Ryugu samples, “which indicates that these minerals in CI chondrites formed attributable to terrestrial weathering.”
After its rendezvous with Ryugu, Jaxa’s Hayabusa 2 mission sampled 5.4 grams of the 1 kilometer diameter near-Earth asteroid’s surface material using an impactor in 2019.
Laboratory evaluation to this point has not only shown Ryugu to be a superb example of primordial Solar System material, and a possible, but has shown it comprises the organic materials vital for making DNA, raising the chance that asteroids not only provided Earth with its water, but provided a number of the constructing blocks of life as well.