Phosphorus-rich grains in Ryugu samples with major biochemical potential
Small bodies in the Solar System are remnants from a complex evolution started about 4.5 Gyr ago. Assessing the composition of these objects contributes to constraining the models of formation and evolution of the Solar System, and to better understanding their possible chemical contributions to the primitive Earth. The successful sample return from the Ryugu asteroid by the JAXA Hayabusa2 mission offers for the first time the possibility of analyzing in the laboratory "primordial" extraterrestrial material rich in carbonaceous matter and pristine, as it has not suffered from terrestrial alteration. The work we report here has led to the discovery of very specific phosphorus compounds with major biochemical potential.
These compounds have been identified and characterized thanks to an international collaboration that performed coupled analyses: first within the ISAS curation facility (Japan) where the Ryugu samples are stored, then in research facilities in Japan, France (IAS and SOLEIL Synchrotron) and UK on some grains extracted from the collection. These analyses have led to the identification of hydrated ammonium, magnesium and phosphorus-rich (“HAMP”) compounds, present as grains and inclusions with sizes up to a few hundreds of microns.
The discovery of HAMPs supports the idea that the Ryugu material must have accreted and partly evolved in the outer Solar System, far from the current Ryugu location. Most of all, a critical specificity of these compounds is that they have likely favored the release and then the reaction of species rich in phosphorus and nitrogen when immersed in primitive terrestrial water reservoirs. They could have thus played an essential role in the evolution towards living organisms on Earth.
Online publication : https://www.nature.com/articles/s41550-024-02366-w
Press release of Université Paris-Saclay/CNRS/CNES : https://www.cnrs.fr/fr/presse/lanalyse-dechantillons-de-lasteroide-ryugu-livre-de-nouvelles-perspectives-sur-levolution
Contacts (Institut d’Astrophysique Spatiale/Université Paris-Saclay/CNRS) :
