How hot is the Moon?

This is going to surprise you, but believe it or not the daytime temperature with the Sun overhead is about 265 Fahrenheit (130 C). Without the Sun, the nighttime temperature plunges to -170 Fahrenheit (-110 C). You would think that walking around on the lunar surface with temperatures 53 F above the boiling point of water would be a problem.

I am actually surprised by the large variations in the answer to this question that you will find on the web. Other estimates you will find: (+107 C, -153 C), (+130 C to -110 C), (+127 C, -173 C), (-200 F to +200 F), (-193 C-polar, to 110 C-equatorial), (400 K to 100 K). Some 'Hoaxers' claim that there is no way that astronauts in space suits could ever survive in that heat, but they forget that space walking Shuttle astronauts experience exactly the same temperature extremes.

During all of the Apollo missions, astronauts used spacesuits that allowed them to avoid being boiled alive. They had undergarments with a liquid cooling system that would move heat from the Sunny-side of the spacesuit to the colder shadowed area to keep them very comfortable. A malfunction in this cooling system, carried in their backpacks, would have been lethal.

This answer was updated in 2011. See my books: The Astronomy Cafe (1998) and Back to the Astronomy Cafe (2003) for more FAQs in printed form. Author: Dr. Sten Odenwald, Copyright 2011

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