Comment on if jupiter gained enough mass to trigger fusion and ignite into a star...
Skua@kbin.earth 5 months agoThe sun and Jupiter are pretty close in terms of density, and Jupiter would need to get at least an order of magnitude heavier to start fusion. I think it's just a coincidence that the outward pressure of the sun's fusion makes these numbers roughly line up.
Thirteen Jupiters seems to be a commonly-given lower limit for fusion, so let's go with that. To increase mass by thirteen times while maintaining density (and assuming the whole thing is a perfect sphere, which it obviously isn't), Jupiter needs to increase its radius by a factor of about 2.35. This increases its equatorial radius to about 168,000 km, which does swallow up the three innermost moons, but leaves the four big ones alones
Davel23@fedia.io 5 months ago
For the four remaining do you know if they'd be clear of the Roche Limit?
Skua@kbin.earth 5 months ago
Oh, good call, I didn't think of that! Assuming I did my sums right, the Roche limit probably destroys the fourth innermost moon, but it still leaves the big four (which are the fifth through to ninth in ascending order of size of orbit). They're quite substantially farther out than the prior four