Best Answer: When anyone asks what "the temperature" is, your very first question should be "the temperature of WHAT?" When "it" gets up to 250 F, you have to know precisely what "it" is. In this case, "it" is the rocks and dust of the lunar surface. That is, the figures cited are lunar surface temperatures.
What we commonly think of as "temperature" in our environment is air temperature. So when you say, "Today it was 75 F in Los Angeles," what you're saying is that the air was 75 F. The hot pavement in the parking lot may have been 150 F. And the concrete floor of the bottom level of a parking garage may be 60 F. That is, each item in an environment doesn't all come to the same temperature.
But more importantly, there's no air on the Moon. So air temperature is meaningless. The surface may get very hot, but that doesn't mean everything nearby will get that hot. How hot something gets in space depends largely on how much heat it absorbs from the sun. The lunar soil absorbs 85-90% of the solar energy (1300 watts max per square meter) that falls on it. So when the sun shines most directly on it it -- lunar noon -- it's sucking up a lot of heat.
A space suit, on the other hand, absorbs only about 15% of the solar energy that falls on it. And the outer layers are heavily insulated from the inner layers. Aluminum absorbs only about 5% of the solar heat. Things made of aluminum don't always heat up very much in space.
An astronaut's boots touch the surface directly and so absorb heat from it. But again, insulation is the key. You can walk very easily in ordinary shoes across asphalt that's 150 F or more without any ill effects. Your shoe soles get hot, but little of that heat conducts to your feet. Same with the astronauts. They had about an inch total of boot sole between them and the ground.
And the other key factor is that the Apollo missions landed in lunar morning. The sun was low in the sky. And just as surface temperatures on Earth take a while to warm up as the sun climbs, so do lunar surface temperatures. I computed once that the average lunar surface temperature during Apollo 11 was only about 30 F. The sun hadn't risen very far yet.
Even at lunar noon, the hot part only goes down less than a meter. Dig more than a few centimeters below the surface, and you've got very cold rocks and dust. The sunlight never penetrates there, and heat conducts very poorly through the jumble of rocks and dust.
Keep in mind that +250 F and -300 F are the extremes. Most of the surface temperatures measured on the surface will lie somewhere in the middle of those. And it takes a long time for any object to change between those extremes. It's not like you stand in full sun and then walk into the shadow of the spacecraft and your suit temperature immediately plummets to hundreds of degrees below zero. Heat transfer just doesn't work that fast.
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