Re: APOD: Exaggerated Moon (2024 Jul 24)
Posted: Thu Jul 25, 2024 3:51 pm
Mars might still be hot enough in its interior that a hole like this can't get too cold.Ann wrote: ↑Thu Jul 25, 2024 3:46 pmWell, there are caves on Mars (or there appears to be).Chris Peterson wrote: ↑Thu Jul 25, 2024 3:19 pm
I don't know about Pluto. All the other moons, though, are tidally locked to their planets, so one side is heated from the planet, and other from the Sun as they rotate/orbit.
Of course, the cold spots on the Moon are created by relatively shallow craters and specifics of the Moon's orientation. If we allow for deeper holes, it's easier never to see the Sun. So it's easy to believe that there are bodies out there with deep sinkholes or old vents that are very, very cold at their bases.
If there really are caves on Mars and the caves are deep and never exposed to sunlight near bottom, could they be very cold?
Ann
Also, the upper parts are heated directly by the Sun, and that heat will radiate to the bottom of the hole. Such indirect heating is significant when we're considering a temperature like 35 K. Even starlight is significant at that temperature (and is probably what keeps the dark craters on the Moon from getting even colder).