SPS Seminar - Samples from asteroid Ryugu returned by the JAXA Hayabusa2 spacecraft – not quite what we were expecting!

When:  Thursday 14 July at 14.00

Where:  Microsoft Teams - Online

Speaker:  Richard Greenwood (PSS – OU)
Hosted by: Alexander Barrett

Abstract:

Between June 2018 and November 2019, the JAXA Hayabusa2 spacecraft made detailed observations and measurements of the C-type asteroid 162173 Ryugu. Two samples were collected and returned to Earth on 6^th December 2020. Near-IR spectroscopic data collected during remote orbital observations indicated that Ryugu comprised material that had experienced significant thermal processing and dehydration, with a possible match to the CY (Yamato-type) chondrites. But when the samples were returned to Earth they showed only minor evidence of reheating and are most similar to CI chondrites – one of the most important groups of primitive meteorites. This was a completely unexpected outcome.

In this talk I will review what has been learnt so far from the laboratory analysis of Ryugu samples. The oxygen isotope laboratory at the Open University was invited at an early stage to participate in the analytical campaign being conducted by “Team Kochi”, one of the three Japanese-led initial analysis teams. I will present our main findings and discuss their implications for volatile delivery to the early Earth and meteorite contamination processes. The Open University has now received a second larger batch of Ryugu samples, which we are currently analyzing in partnership with Team Kochi. We fully expect some further important results in a campaign that has already greatly exceeded initial expectations.