this French laboratory analyzes asteroid dust dating back to the origin of the solar system

The Nancy Petrographic and Geochemical Research Center is one of the laboratories around the world tasked by NASA with analyzing these rock particles, taken in 2020 tens of millions of kilometers from Earth by the Osiris Rex probe.

Behind the glass door, a vast room occupied by computers and various advanced instruments, tangles of cables, sensors and pipes surrounded by aluminum. This is where researchers from this CNRS laboratory and the University of Lorraine, specializing in the study of rare gases, are working on this extraterrestrial dust, dating back to the origin of our solar system. They arrived from the United States at the end of 2023. The Center for Petrographic and Geochemical Research (CRPG), located on the outskirts of Nancy, is one of the laboratories which was tasked by NASA with analyzing these particles.

The announcement was made at the beginning of the week: NASA has finally managed to completely open the container filled with samples from the asteroid Bénou. For months, experts from the American space agency have been fighting with the recalcitrant cover of this capsule containing these rock particles taken in 2020 tens of millions of kilometers from Earth by the Osiris Rex probe. Only part of this precious cargo had so far been recovered and sent for analysis to various laboratories around the world, including the CRPG.

“The first step was to take photos of them and look at them under a microscope to be able to choose those that interested us.explains research engineer Laurent Zimmerman. Then, we had to handle them with care because they are extremely fragile samples to handle and we weighed them. We managed to weigh a maximum of hundreds of micrograms.”

“Pure rare gas”

Locked in an airtight cylinder, these asteroid fragments are then ready to reveal their secrets, under the heat of a laser beam. An operation followed on his screen by Evelyn Füri, research fellow at the CNRS: “Do you see the little grain there? We will increase the power of the laser to heat our small grain at different temperatures until it melts. And, like that, at each temperature level, we will extract the gases. Once the gases have been extracted by heating or fusion, there is this whole part of gas purification, in order to remove all the gas phases that we do not want to analyze. And in the end, we hope to have a clean gas, that is to say only composed of pure rare gas or pure nitrogen, in order to analyze it.”

An analysis which makes it possible to map these rare gases, such as radon or helium. There are six in total, depending on the atomic structure found. “Depending on the isotopic ratio of these gases, which are a bit like their DNA, we try to trace sources or physical processes“, deciphers Evelyn Füri.

So many clues which will allow us to better trace the history of these rocks of this asteroid, and of our origins, when this large rock was formed, around 4 and a half billion years ago. Initial results should be revealed in the spring, during a conference in Huston, in the United States.