It's cold out there! Sometimes I wonder whether humans as well as birds should fly south for the winter...

Being cold is a very interesting subject. Much of it has to psychological factors - most people know that you can consciously stop yourself from shivering - or start it yourself. I'm not sure what's the coldest I've ever been, but something that does come close is when I went swimming (albeit briefly) in the splashpool of a mini-waterfall. This wasn't a planned event, no, we just got there and thought that it might be fun to go in. Of course, once I got into the water I had to make sure that I kept my mouth closed or else I'd be spewing a constant stream of expletives about the temperature - there were youngsters about, after all.

Compared to other 'space' locations such as space itself and the Moon, Mars is a fairly balmly place. At times, the surface temperature can be over 20ºC at the equator in summer, and then drop to maybe -100ºC at night; the average temperature is -48ºC and the temperature differential can be 100ºC over a matter of mere hours. [I presume that there is also a nasty temperature differential between the Martian ground and air, which is something I have to look up one of these days]

Anyway, the fact is, Mars is really only as cold as the more frosty parts of the North Pole and Siberia - it's a temperature that we can cope with. Temperature is not the problem, as we well know. The pressure is the problem. Mars' atmosphere is about 0.8% of that of Earth's, so anyone going out onto the surface will need a fairly good pressure suit to prevent blood vessels from rupturing and so on.

If you look at space suits these days, they've hardly changed in 40 years - the space suits worn on the Moon look pretty much the same as those worn by shuttle astronauts on spacewalks. That's all very well and good, because they do their job, except they are not particularly flexible at all and they wear out after a while on exposure to dust. The fact is, if humans go to Mars, we'll need a completely new type of space suit. Moonwalkers found that after a few trips outside, their suits would begin to gum up as the dust inflitrated their suit joints - any more trips and the entire thing would be unuseable. This is clearly not an option for a Mars mission which could last from anywhere between a month to 18 months.

So. The new idea is that we'll have a skin-tight pressure suit that will maintain pressure, be flexible and allow complete freedom of movement while have no gum-uppable joints. Easier said than done. I don't really know how this pressure suit will work, but I heard that you have to be absolutely sure that it's skin tight or else bubbles will form and you'll be in big trouble. Naturally, such a thin pressure suit will offer no protection against the cold - so you just go and put a coat on, or maybe some coveralls. A parka might do well. It'd definitely be a sight.