# Can an asteroid have a molten core?

Most natural satellites in our Solar System are expected to contain fission furnaces at their cores, and some of these moons do have a striking resemblance to an asteroid. I'm wondering if we could establish a colony on an asteroid and harvest the "aster-thermal" energy (if there is a proper term for it) or rather create a space tourism hotspot for people to enjoy a relaxing bath in the hot spring. Is it possible for an asteroid to contain a molten core or do I need to look elsewhere to locate my "colony"?

• Haha.. Seriously? Hot spring bath in nearly zero G? – user931 Mar 26 '15 at 6:20
• what happens why did the migration took place automatically and unauthoris-tically? I learnt a moment ago that these two genres/categories are at two extreme end of the spectrum! Anyway please keep the answers coming as they are good scientifically, theoretically and logically speaking. – user6760 Mar 26 '15 at 6:22
• This question is suitable for Physics.SE, I think.. – user931 Mar 26 '15 at 6:23

Yeah, entirely possible.

There are a couple of examples of asteroids that we've identified which may have, or recently had, molten cores. 21 Lutetia is a notable example. Vesta is another.

The main issue is that because of their size, the ratio of surface area to volume is higher than the average planet. This means it cools much faster. So while some may have molten cores, they won't stay that way for as long as a planet might. Additionally, most aren't very near large gravity wells like a moon might be, so they don't have the same tidal forces adding energy to their interiors.

All this makes it less likely to find an asteroid with a molten core, but it's not impossible.

• @PiminKonstantinKefaloukos Note that the surface area of a sphere is given by $4\pi r^2$ while the volume is given by ${4\over 3} \pi r^3$. The volume grows much faster than the surface area for an increasing radius. Thus for a smaller radius the surface area to volume ratio is higher than for a larger radius. – Samuel Mar 26 '15 at 15:47
• @JDługosz ha ha, what was I thinking. Thank you for referencing the principle that was stated by Galileo Galilei. Nice to learn something cultural. – Pimin Konstantin Kefaloukos Mar 27 '15 at 22:14

Ceres is the largest asteroid (or smallest dwarf planet, whatever); the core isn't molten based on best current data and modeling, but new data is forthcoming soon, in the sense of Earth, Io; but it may be warm enough to have liquid water. Note that Mars also doesn't have a molten core and that Io and the Moon, etc. have molten cores due not to nuclear decay or to primordial heat but gravitational energy primarily.

• Suggest you wait a few months before making blanket statements about Ceres :-) – jamesqf Mar 26 '15 at 18:15
• true, we should have more information on it in the near future. – John_H Mar 26 '15 at 18:17