Niven, Larry
In his 1964 science fiction story “The coldest place”, author Larry Niven described the “dark side” of Merc
In his 1964 science fiction story “The coldest place”, author Larry Niven described the “dark side” of Mercury as the coldest place in the solar system. What assumption did he make about the rotation of Mercury? Did this assumption turn out to be correct?
The assumption that Niven (and other sci-fi writers) made in that era was that Mercury didn’t rotate at all with respect to the sun, thus keeping one side always in sunlight and the other always in shadow. This made Mercury’s dark side the coldest place in the solar system because it **never** received any sunlight.
Nowadays, we know that assumption is not true. Mercury’s orbital period around the sun (its “year”) is about 88 days, but it completes one rotation (its “day”) once approximately every 59 Earth days.