I was wondering about the possible surface g of this giant rocky planet, and I found this one origin hypothesis on wikipedia. "If an eroded gas giant, the sun would have boiled the planet from a larger protoplanet, of 20 Earth masses up to half Jupiter's mass. If the latter, its current radius could be as high as 0.6 Jupiter." With this radius/volume estimate, and the mass (10.5 Earths), put into a density calculator, we get a puny and utterly impossible 189.74kg/m^3. If it's the remaining solid core of a gas giant, shouldn't it be incredibly dense? And it simply cannot be this diffuse. Balsa wood can sometimes be heavier than this. This is 0.034385647 x Earth's density. Even Saturn is about six times denser. Using this mean density with the estimated maximum radius, I get only 0.2g. Before I mixed up kg/m for g/cc and got the g to 34.385646974g and with the early 14e mass of the planet, I got the ridiculous figure of 310g. So, I've got it either way too heavy or way too light. Where have I gone wrong? Or is the radius estimate on wiki waaaaaaay off. I wouldn't expect it to be that large after all. I've seen 3.5g for this planet before, but I don't know how that was come to.