# How did the astronauts cope with the drastic temperatures on the moon?

The moon is 100C in the day and -200C at night. How did the astronauts cope with these extreme temperatures?

They wore spacesuits.

I don’t believe the astronauts ever experienced ‘night’ on the moon. A lunar day would last a month.

Actually day lasts half a month, and night the other half.

Anyone have a good answer for the temp difference on the moon between full sunlight and shade?

The astronauts landed at local morning, before the surface got raging hot.

There’s no atmosphere on the moon (although the food’s decent), which means there is a lot less opportunity for heat to dissipate. Heat can’t travel through a vacuum directly. Basically if you’ve got oven-proof shoe soles, you’re good for a long while.

Interesting but even so, I can’t imagine a space suit would protect me from 100 C for very long.

But they do, nonetheless. The lunar spacesuits circulate chilled liquid.

You say “the moon is 100C in the day and -200C at night”. That may be true (I haven’t checked the figures), but that’s the point - the surface of the moon is.

On a baking hot day on Earth, you might say “It’s 45C today”. By that, you mean the ambient temperature of the air is 45C. You’re surrounded by the air, so that’s the temperature you experience. On the moon, though, there is no air, so there is no “it” to have a temperature. Different objects will have different temperatures, depending on their thermal and absorption characteristics, but you can’t say “It’s 100C today”. One side of a given rock on the surface may be 100C, but the other side, in the shade, may be less, and the surface of your spacesuit less again.

It’s a dry heat.

Wikipedia sez:

``````

min       mean        max
equator           100 K     220 K       390 K
85°N                 70 K     130 K         230 K

``````

EDIT: screw it, I can’t get that lined up.

I’d say that infrared radiation does a fairly good job of traveling directly through a vacuum.

Temperatures are meaningless. What matters is heat transfer (the same reason why you can last a long time outside in your underwear with an air temperature of ~34F, but jump in a lake at ~34F and you’re dead within a couple minutes).

On the moon, once you’ve insulated your feet (as the above poster mentions), the only thing you have to worry about is heat transfer from solar radiation(including reflected radiation off the moon’s surface), body heat, and heat buildup from the electronic equipment inside your suit. Size your cooling system for those three things, and you’re set.

Out of curiosity, why do you think this? I remember seeing a show on one of the cable channels where skeptics of the moon landings were discussing this, but for the life of me I couldn’t figure out what their problem was on this issue (nor the vacuum issue either…though it was hilarious to watch the one old guy try and move his hand in the evacuated chamber as if this proved something).

Could you give some details as to why you find it hard to believe that a space suit could have these performance characteristics?

-XT

Yes, so does light. That’s why I qualified it with ‘directly.’

So what’s indirect about the way radiation travels through a vacuum? I would have said that few things are more direct.

It sneakily bypasses the vacuum and travels through the luminferous aether.

I said heat can’t travel directly through a vacuum. Like visible light, infrared radiation is not heat. A lot of it gets converted to heat when there’s a medium that it finally hits, but the radiation is not heat.

Thermoses take advantage of the fact that heat can’t transfer through a vacuum.

So it doesn’t matter much that the surface of the moon is hot, since there’s no atmosphere to transfer the heat. You get heated on the moon from the sun’s rays converting to heat when they strike you, the reflected light off the moon converting to heat when it strikes you, and through the soles of your boots actually in contact with the surface.

The actual heat in the surface that your boots aren’t touching doesn’t transfer to you.

I think you’re discounting the problems they’d have with heat, other than that conducted through the boot soles.

First, the problem with direct radiated heat from the Sun would be less of a problem when the Sun was high overhead, because it would be hitting you from directly above and thus over a smaller surface area. You’ll get more solar radiated heat at local morning or evening because it’s hitting your whole body. I suspect this is why their suits were white.

Further, if you’re walking around on a plain of something that’s 200C, the radiated heat from the Moon’s surface seems like it would be the biggest problem, not the heat transferred through your boot soles.

So in the proposed Moon base that they’re talking about, how do they plan to deal with the heat extremes issue?

I think your position here is defensible, but not mainstream. Wiki is one of vast numbers of sites that list the three classic methods of heat transfer: conduction, convection and radiation.