How much water lurks beneath an exoplanet's surface? New tool could help astronomers tell

Jan 28, 2023
Visit site
In title "new tool" below it "new technique". From the text is clear that is just another theoretical work. This is relevant to our level of technology development which is far away from possibility to real remote sensing in depth, from our location, of the lithospheres of the exoplanets. Well, we can't do very well even with such an observation of our own planet, Earth.
  • Like
Reactions: rod
The ref paper, Mantle mineralogy limits to rocky planet water inventories,

looks interesting. "ABSTRACT Nominally anhydrous minerals in rocky planet mantles can sequester multiple Earth-oceans’ worth of water. Mantle water storage capacities therefore provide an important constraint on planet water inventories. Here we predict silicate mantle water capacities from the thermodynamically-limited solubility of water in their constituent minerals. We report the variability of upper mantle and bulk mantle water capacities due to (i) host star refractory element abundances that set mantle mineralogy, (ii) realistic mantle temperature scenarios, and (iii) planet mass. We find that transition zone minerals almost unfailingly dominate the water capacity of the mantle for planets of up to ∼1.5 Earth masses, possibly creating a bottleneck to deep water transport, although the transition zone water capacity discontinuity is less pronounced at lower Mg/Si. The pressure of the ringwoodite-perovskite phase boundary defining the lower mantle is roughly constant, so the contribution of the upper mantle reservoir becomes less important for larger planets. If perovskite and postperovskite are relatively dry, then increasingly massive rocky planets would have increasingly smaller fractional interior water capacities. In practice, our results represent initial water concentration profiles in planetary mantles where their primordial magma oceans are water-saturated. This work is a step towards understanding planetary deep water cycling, thermal evolution as mediated by rheology and melting, and the frequency of ocean planets."

I use these two exoplanet sites for my studies., and

It would be good to see an exoplanet cited as an example that could support the model here. The site shows 35 exoplanets with mass ranges 0.1 to 1.5 earth masses. The TRAPPIST-1 system falls within this mass range too. I found 41 exoplanets using the nasa archive site.