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Exceptional Seeing At Dome C in Antarctica

Posted by timothy on from the but-it's-such-a-long-drive dept.

Michael Ashley writes "A paper published in Nature today reports on the exceptional astronomical seeing conditions at Dome C (Coral link) in Antarctica. Obtaining the data posed some significant technological challenges, given that Dome C is uninhabited over winter. The experiment was controlled by a PC/104 computer system that had to survive temperatures down to -85C, and supervise the generation of its own electricity using a jet-fuel powered stirling engine. The computer, running Linux, communicated with the outside world using an Iridium phone. The results are also covered in New Scientist, and the Sydney Morning Herald. Disclaimer: I'm a co-author."

4 of 252 comments (clear)

  1. Three cheers for global pollution by nlawalker · · Score: 5, Funny

    Looks like making the ozone hole actually accomplished something.

  2. Seeing Conditions by ottergoose · · Score: 5, Informative

    What is "seeing"?

    "Seeing" is a term that astronomers use to quantify the turbulence in the atmosphere and how it affects observations from the ground. The stars appear to twinkle because of the effect of this turbulence. In conditions of bad seeing, the stars appear to twinkle vigorously, and the images that you take with your telescope are blurry. In conditions of good seeing, the stars appear more stable, and you can take very sharp images.

    You'd think they'd have a cooler word for that...

  3. PC/104 Computers... by DiS[EnDeR] · · Score: 5, Interesting

    I work with Diamond Systems PC/104 computers everyday. These systems are robust and the specifications for operating environments are crucial to applications such as these. Their ability to operate in extreme conditions, temperature, vibration, make them fit for such roles.

    We've used PC/104 computers (running QNX 4.25) for everythign from Remote power stations, Fuel cells, even UAV's.

    --

    Harder.. Better.. Faster.. Stronger
  4. Re:Surviving temps down to -85??? by Waffle+Iron · · Score: 5, Informative
    When you do a circuit design, you take into account both maximum and minimum delay paths. These are usually spec'd over a recommended operating temperature range, which most likely doesn't get quite that cold.

    While colder can often mean faster, sometimes a signal requires some minimum delay to work correctly. This is especially true of the minimum hold times required on inputs after a clock transition. So it's possible that some signal might go out of spec if you drop the temperature too far. It only takes a single bad signal to hose the whole system.

    Unlike just dropping the temperature of the CPU chip which will have relatively uniform characteristics, getting the whole system cold might cause a wider range of timing variations. Moreover, even dropping the external heat sink of a CPU to extreme cold doesn't mean the chip itself is in the cryogenic range. They usually run at temps well above the bulk of the heatsink.