4 ms·
Why is the metallicity of the sun so low when they are so high for the planets?
by steffenfrost 6y ago
Why is the metallicity of the sun so low when they are so high for the planets?
- ncmncm 6y agoWhich planets? The big ones are mostly H2. The small fry with weak gravity lose theirs.
- steffenfrost 6y agoThere is new data from the Juno Mission, that Jupiter has a diluted core. "...heavy elements (elements other than hydrogen and helium) are distributed within a region extending to nearly half of Jupiter’s radius." https://www.nature.com/articles/s41586-019-1470-2 https://www.nature.com/articles/s41586-019-1470-2
- kadoban 6y agoI think because H2 is so common. Given that and how gravity works, let's look at the possibilities: small thing (say up to size of smaller planets): only solids can clump together and stay together, gas would just fizz away medium thing (earthish to gas giantish, say): solids clump together and that provides enough gravity (and sometimes magnetics) to capture/keep some gas too large thing (star sized): you can just capture everything around. Sure that'll contain some metal, but since most of what's out there is H2 and you're gulping it all up, you end up mostly gas