Slashdot Mirror
Chinese Team Heading for Coldest Spot on Earth
LMCBoy writes "Dome A is the highest point on the Antarctic Plateau, and it has never been reached by humans. It is thought to be the coldest place on earth, and is certainly among the most remote. Yesterday, a team of Chinese explorers set out from Fremantle, Australia to reach Dome A and set up a robotic weather station which will monitor the local conditions for up to five years. The team is expected to arrive at Dome A in early 2005."
to set up a robotic weather station which will monitor the local conditions for up to five years
...
Day 1: Cold
Day 2: Cold
Chinese Team Heading for Coldest Spot on Earth
Let me know when they find my girlfriend's heart.
--------
Bleah! Heh heh heh... BLEAH BLEAH!!! Ha ha ha ha...
China seem to be determined to push boundaries at the moment. Putting a man in orbit is no mean feat. Yes the US did it along time ago, but I don't see them doing it at all at the moment due to the shuttle grounding. Now pushing for the still unexplored regions of the world. I wonder if they have any deep sea missions planned for some time in the next few years. China has definitely decided that they have somethign to prove. The impressive part is that they aren't doing a bad job of proving it.
And this really ought to mildly concern people in the US. Yes the US already has done most of these things or something similar (they have a couple of Antarctic bases, one at the pole I believe). But that's the key point. The US has done such things, but doesn't seem to be expending quite the effort they use to on pushing boundaries of exploration and science. Increasingly it seems to be Chinese and Indians with the real fire to try and push ahead. And all the better I say. The US seemed to slacken off and grow complacent, so its about time there was some serious competition again.
Go China.
(Hopefully they can break new ground sorting out their political issues too)
Jedidiah.
Craft Beer Programming T-shirts
The Chinese aren't going there as a big PR exercise. If you haven't noticed, the Chinese aren't big on grand, meaningless showboating: they do what they do because it furthers their long-term objectives, not because it wins them short-term positive press coverage.
The long-term thinking and objectives behind this sort of expedition is space exploration. If the Chinese can successfully establish a base in one of the least hospitable places on the planet, and overcome the physical, logistical, pyschological and other hurdles that such an endeavour involves, then they will have gained valuable experience and climed another rung up the ladder towards the eventual establishment of a populated lunar or Martian base.
They aren't going there for the scenery, they're going there to take some hard knocks and learn from them.
"Accept that some days you are the pigeon, and some days you are the statue." - David Brent, Wernham Hogg
"the temperature plummets to around minus 90 degrees Celsius"... of course, we don't know how that measurement was made...
I've had this sig for three days.
That is actually not a bad question but I think you'll find that the breathing reflex is not affected by the composition of the air in the environment - rather, it is related to the carbon dioxide concentration in the blood. The carbon dioxide is created within the body as a by-product of aerobic respiration. If that carbon dioxide is freezing before they have the chance to expel it, they wouldn't be needing a breathing reflex anyway.
Silly, parachutes don't work when they're upside down!
I helped design those weather stations, we use 148 Saft Lithium-thionyl chloride (Li-SOCl2) 20 AHr batteries. The weather station averages about 1 mA at 12 V. The batteries aer burries in the snow about 3 m where we expect the temperature to be about -65 C.
We cannot find any batteries that could be recharged at this temperature, Li-SOCl2 batteries are the only option. We also have solar pannels for the summer months. Without the solar pannels the station should last 5 years, with the pannels we might get 7-10 years, and 20 years of data for summer.
The trick with getting things working at that temperatures was testing, we find that most things work (chips etc) but we test all the parts here first.
Peter Jansen
Australian Antarctic Division
It appears that it takes liquid CO2 to make dry ice.
e _makers.html
From a google search.
Basically, dry ice is frozen carbon dioxide (CO2). CO2 is usually found as a gas -- it's what we exhale. To make dry ice, CO2 is compressed, and it liquefies at a pressure of approximately 870 pounds per square inch. The dry ice press then reduces the pressure, and part of the liquid CO2 sublimates (meaning it turns from a solid into a gas). The remaining liquid freezes into flakes that are compacted into solid blocks. The resulting dry ice is denser, heavier, and colder than ice made from water.
Here is a link to a machine that can make a block of dry ice in 60 seconds with just a liquid CO2 cylinder, and it costs less than 600 USD.
http://www.amer-rest-equip.com/usare_polfo_dry_ic
You said: "So what happens when the temperature (down to -90C) goes below the sublimation temperature of CO2 (-76C, if I recall correctly)? Does it just freeze out of the air?"
Most likely. The phase diagram for CO2 shows that for our standard atmospheric pressure, CO2 freezes at -78.5 C. If the temperature is only slightly lower than -78.5 C it may take some time for a significant amount of CO2 to precipitate due to the latent heat of solidification for CO2 of -43 cal/g (smaller than the absolute value of water which is about -80 cal/g) . Additionally some CO2 may remain in the air which varies by temperature (which would be relative humidity for water). As the temperature drops the amount of CO2 that can be dissolved in air decreases. Unfortunately I couldn't find a reference for CO2 saturation vs temperature. If it is reasonably low (which it should be) at -90 C, CO2 frost will develop.
On Mars with an atmospheric pressure that varies from about 5 - 10 mbar (1 atm = 1013.25 millibars), CO2 frost can develop as seen by Viking 2 and by satellite pictures of the poles. Snowflakes won't form, since the shape of a snowflake is determined by van der Waals forces (don't occur in CO2). CO2 frost should look similar to this.
Suddenly, the hairy finger of a familiar monkey tapped me on the shoulder. It was time.--G. T.
Thermal imaging from satellites?
if you happen to live in Taiwan.