beecee Posted February 11, 2022 Posted February 11, 2022 (edited) https://phys.org/news/2022-02-asteroids-sample-earth-reveals-solar.html What are asteroids made of? A sample returned to Earth reveals the solar system's building blocks; Just over 12 months ago, we were sitting at Woomera, in the Australian outback, waiting for a streak of light in the sky to testify that the Hayabusa2 spacecraft had returned from its voyage to collect a little piece of a near-Earth asteroid called Ryugu. Unfortunately for us, it was cloudy in Woomera that day and we didn't see the spacecraft come in. But that was the only imperfection we saw in the return. We found and retrieved Hayabusa2, brought it back to Woomera, cleaned and examined it. The sample capsule was removed from the spacecraft. It was in good shape, it had not exceeded 60℃ on reentry, and the capsule rattled when it was turned over, suggesting we did indeed have a solid sample. Its vacuum had been maintained, allowing whatever gases had been released from the asteroid sample to be collected, and a preliminary analysis of these was carried out in Woomera. more at link.......................... the paper: https://www.science.org/doi/10.1126/science.abj8624 Pebbles and sand on asteroid (162173) Ryugu: In situ observation and particles returned to Earth Abstract: The Hayabusa2 spacecraft investigated the C-type (carbonaceous) asteroid (162173) Ryugu. The mission performed two landing operations to collect samples of surface and sub-surface material, the latter exposed by an artificial impact. We present images of the second touchdown site, finding that ejecta from the impact crater was present at the sample location. Surface pebbles at both landing sites show morphological variations ranging from rugged to smooth, similar to Ryugu’s boulders, and shapes from quasi-spherical to flattened. The samples were returned to Earth on 2020 December 6. We describe the morphology of >5 g of returned pebbles and sand. Their diverse color, shape and structure are consistent with the observed materials of Ryugu; we conclude they are a representative sample of the asteroid. :::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: The most amazing though expected revelation imo is the following extract...... "These meteorites are unique in being made up of the same elements as the sun, and in the same proportions (besides the elements that are normally gases). We think this is because CI chondrites formed in the cloud of dust and gas that eventually collapsed to form the sun and the rest of the solar system. But unlike rocks on Earth, where 4.5 billion years of geological processing have changed the proportions of elements we see in the crust, CI chondrites are largely pristine samples of the planetary building blocks of our solar system". Edited February 11, 2022 by beecee
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