Swiss scientists want to use asteroid Ryugu to find out how water formed on Earth

By Timo Kirez

GENEVA (AA) - Two Swiss research projects are receiving tiny grains from the famed asteroid Ryugu for a study to find out where water on Earth came from, according to a statement Tuesday from the University of Lausanne.

"Ryugu is about 4.6 billion years old," Nicolas Graber, research officer at the Natural History Museum of Geneva (NHMG), told daily Blick. Graber is co-initiator of one of the two Swiss research projects selected by the Japanese Space Agency (Jaxa).

In addition to the joint project by the NHMG and the University of Lausanne, researchers at the Swiss Federal Institute of Technology in Zurich (ETH Zurich) will also receive asteroid dust.

The Ryugu asteroid thus dates from the time when our solar system and planets formed, Gerber said. The special feature of the samples from Ryugu, however, according to the Geneva researcher, is that they were obtained directly from the asteroid.

Unlike meteorites, from which similarly old rock samples were already available before, the rock particles from Ryugu did not fly through Earth's atmosphere without protection and also did not mix with any elements on Earth. So the researchers can study the samples as they were found on the asteroid.

Just 5.4 grams of the asteroid Ryugu was brought to Earth by Japanese space travelers in 2020. The Swiss scientists are studying grains from the asteroid which, with a size of 50 to 100 micrometers, are about as thick as a hair.

The ETH Zurich project is investigating the noble gases trapped in the samples. The research project in western Switzerland is focusing its analysis on two minerals: sulfides and apatites.

Among other things, these analyses should reveal information about the nature of the fluid that flowed through Ryugu.

"We will try to reconstruct the composition of the oldest water in Ryugu and find out if its chemical signature is comparable to the water on our planet," Gerber explained.