[seastay]

Who would have thought Triton would be about as cold as our moon? Wondering if it is speculated that some places are colder, considering this is the coldest measured? Are there predictions of absolute zero existing anywhere in the universe?

[dr_lew]

Who would have thought Triton would be about as cold as our moon?

It's just these few spots on the moon. The unique properties are the stable orientation of the moon, the lack of volatiles, and hence atmosphere ( as omega4179 points out, ) and the deep craters. Triton is flat because the icy surface cannot sustain vertical relief.

It certainly is a surprising assertion, but solar radiation in space is directional, and if you are effectively shielded from it you will obtain deep cold by radiating directly into space.