4 ms·

I have to ask: why is the astroid glowing red through various cracks, other than to make it look more scary?

• dredmorbius 5y ago
  I'm inclined to think that's artistic embellishment. There might be some disruption of the asteroid during its final approach due to tidal forces from the Earth. Whether or not that would result in significant heating of the asteroid's interior is another question. Early in the history of the solar system, it's possible that many bodies were still hot from latent heat of formation (effectively: the conversion of gravitational potential energy to heat, plus whatever contribution comes from radioactive materials in the body). Note that the heat of Earth's interior is just this, still leaking slowly into space after 4.5 billion years. Large objects take time to cool, and the vacuum of space eliminates conductive and convective cooling, leaving only blackbody radiation. Thermal management is a major issue for satellites and space probes, particularly if they have a significant energy demand.