The IPGP, a long history of analysing extraterrestrial material

• The IPGP has a 50-year tradition of analysing extraterrestrial material. What are the main samples that have been analysed here?

Frédéric Moynier : “Since the return of the first lunar samples with the Apollo and Luna missions, IPGP researchers have played a crucial role in the analysis of a wide range of extraterrestrial samples. Their expertise extends not only to lunar samples – the IPGP was the first French laboratory to date these samples in the early 1970s – but also to meteorites, the fragments of celestial bodies that have fallen to Earth. In-depth study of these different samples helps us to better understand the origin of the planets and to unveil the mysteries of our solar system.
More recently, the IPGP took part in the Hayabusa2 mission, an important step in space exploration, as this mission succeeded for the first time in collecting and bringing back to Earth samples of the carbonaceous asteroid Ryugu. The analysis of these few grams of asteroid provides unique access to the composition of these celestial objects, enabling us to learn more about their formation and evolution, and more generally about the origin of the Solar System.”

• What makes the institute such an expert in this field?

F. M. : “At the IPGP, we have an exceptional analytical platform, unrivalled anywhere in the world, with certain instruments specifically designed for the fine isotopic analysis of extraterrestrial samples. For almost 50 years, our teams have been developing ever finer analytical techniques and methods, using increasingly precise instruments to carry out isotopic analyses on extremely small quantities of material.
Thanks in particular to our new-generation plasma source mass spectrometer, funded by the DIM ACAV+ of the Île-de-France region, and equipped with a collision cell, we have been pioneers in these high-precision isotopic measurements, and we have been able to analyse the isotopic composition of samples from Ryugu for several elements (Calcium, Copper, Zinc, etc.) present in minute quantities, which has enabled us in particular to demonstrate the very primitive nature of the matter that makes up Ryugu”

• What can these samples tell us about the history of the Earth and the solar system?

F. M. : “

The study of lunar samples brought back by the American and Soviet missions has revolutionised our understanding of the formation of the Moon and the Earth. In particular, this led to the emergence of the giant impact theory, which suggests that a planet the size of Mars collided with the Earth, giving rise to our natural satellite, the Moon. However, most of the lunar samples we currently have come from a limited area, relatively close to the lunar equator. As a result, our knowledge of the Moon may be biased due to the lack of samples from the polar regions and the far side (although lunar meteorites do provide us with some).
The samples recently recovered by the Chang’e 5 mission offer a new perspective on our satellite, since they come from a region further away from the lunar equator and are about a billion years younger than the most recent Apollo samples.

In the coming years, we will also be involved in the mission to return samples from Phobos, a Martian moon due to be launched by the Japanese space agency in 2024. Thanks to these samples, we should be able to settle the debate on the origin of Phobos, whether it was a giant impact or an asteroid captured by Mars. We are also helping to prepare for future NASA and ESA missions, which are planning to return samples from Mars within the next ten years or so.”