Published: | By: Ute Schönfelder
From the size and number of the ice crystals detected, the researchers can also estimate how quickly the asteroid loses sulphur. "The process is incredibly fast from a cosmic perspective," explains Toru Matsumoto. The crystals he analysed are up to two-and-a-half micrometres long, which is around one-fiftieth of the thickness of a human hair. "The tiny whiskers have already reached these sizes after around 1,000 years," adds the researcher from Kyushu University in Fukuoka. Over the long term, the analysis of the ice crystals can be used to gain a better understanding of weathering processes on other celestial bodies as well, and to determine their age.
To this end, the researchers already have specific asteroids in their sights. NASA’s OSIRIS-REx probe is currently preparing to take samples from asteroid Bennu, while JAXA’s Hayabusa2 is already on its way back to Earth. The Japanese probe visited the Ryugu asteroid last year and, as with Itokawa, it collected dust particles. The samples should land on Earth at the end of 2020 and the international team of Jena mineralogists and Toru Matsumoto are awaiting them with anticipation
Matsumoto T et al. Iron whiskers on asteroid Itokawa indicate sulfide destruction by space weathering. Nature Communications (2020), DOI: 10.1038/s41467-020-14758-3, https://www.nature.com/articles/s41467-020-14758-3