In Nature Astronomy today (21 Oct.):
Matthew A. Pasek, Ryugu’s unexpected phosphorus materials, s41550-024-02387-5
Not only was phosphate in asteroids significant (as I already blogged), but it’s news enough to have the journal Nature bring in an expert to give a recap. Phosphate is, if not big news (we’ve found trace phosphates in meteorites before), then a big deal. Phosphates per se are useful as fertilizers (in foresight) and deposited in aqueous environments (our hindsight, from geology- “important water reservoirs“). Flash back to the current day, phosphates are a carrier of water (as Mgx[P2O5]2 · H2O), a previously unrecognized carrier. Not to be redundant, but this is a big deal.
Again, phosphates deposit in liquid-water environments. They are destroyed by heat, indicating phosphate-bearing bodies are primitive and (reasonably) undisturbed. They preserve some of that liquid water as bound hydration, and even if somehow heated to the point of dehydration are still worthy and enabling as fertilizer (earthly life cannot survive without this vital element).
We have discovered phosphates in Ryugu and Bennu. More than trace phosphates. This is a big deal.