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Exceptional Seeing At Dome C in Antarctica
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."
Looks like making the ozone hole actually accomplished something.
polluters, the other scientists.
for providing a Coral link with his article. Good jorb!
Come to the University of Mars! Classes starting soon!
Dome C is uninhabited over winter. The experiment was controlled by a PC/104 computer system that had to survive temperatures down to -85C
Now, that's a savage dome!
Free XBox, PS2
The experiment was controlled by a PC/104 computer system that had to survive temperatures down to -85C...
;-)
Wait a sec! =-P Computing equipment *loves* cold, as long as you don't have to worry about condensation. =-P In other words, it's not hard to design a system that can survive -85C. Just do a google search for Liquid nitrogen cooling. Yay for overclocking fiends who make it so you don't even need to mention computing hardware.
btw, there's a tom's hardware link on the results page. Check it out. There's a pic of a CPU mount covered in frost. That *can't* be good! =-P
But nerds are my mortal enemies"
-Homer Simpson
Look at this photo. It is the author's Kyocera mobile phone with a web page showing the temperatures, memory usage and free disk space. Says battery temperature is -34.5 (is that C or F?)
2bits.com, Inc: Drupal, WordPress, and LAMP performance tuning.
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...
I would have to say Linux was the ideal choice in this case. Penguins are polar creatures. you know. I wonder how the Microsoft Rainbow-bee-man would've fared under such conditions.
An Indian-American Hindu committed to non-violent thought/speech/action alarmed by the global explosion of radical Islam
Hell, all that they had to do was stick a new Geforce and an Athlon in there and she'd be warm as toast ;)
You create your own reality - Leave mine to me.
... does the PC/104 run Linux? No really, I'm curious ... never heard of it before.
(Don't bother to mod this post up, I've got all the karma I could possibly spend.)
The link that the submitter provided to himself doesn't work. The correct link is: Michael Ashley
God I hate those jerks in Dome C!
Iridium? Didn't they go out of business a few years ago?
Or have they switched to niche markets like in this case?
2bits.com, Inc: Drupal, WordPress, and LAMP performance tuning.
... oh yes:
Cool!
---- MISSING MISCELLANEOUS DATA SEGMENT --- [sigdash] trolololol
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
This is offtopic, but how's that Coral link thingy work? As it open participation?
Direct away from face when opening.
madam jojo can see all but she's modded +5 lunatic, not insightful
Base camp: So how's it going there?
Dome C: Weh, Biwwy daywed me to stiwck my tung to the waw. Oh, and we'we outta beew....
"All great things are simple & expressed in a single word: freedom, justice, honor, duty, mercy, hope." --Churchill
But I've applied for a job down there (no reply so out for this year); anyone work down there and have any advice for getting a foot in the door?
Thanks
Vote monkeys into Congress. They are cheaper and more trustworthy.
PC/104? I guess Internet keyboards aren't rated for the cold.
One experiment, ICECAM, relied entirely on a 5 kg pack of lithium thionyl chloride batteries. The batteries had to provide power for a year, so minimized the power consumption of the computer. The experiment only needed to take data every two hours, so we built a CMOS oscillator to power-up the computer for 30 seconds every two hours. We used MS-DOS 6.22 for the PC/104 computer since it boots quickly and was able to average 10 frames from the CCD camera and store them to CompactFlash disk.
www.bannination.com Two things float to the top he
at -40 F/C. Thus, it's not too far off. -34.5 C is -30.1 F, and -34.5 F is -36.9 C. When it's that cold, 5-10 degrees each way makes no difference. I camped on the ice of the Ottawa River in February, and let's just say I don't want to experience -30 C windchill again.
The hard part would be coming up with a thermal control system that worked at both extremes, a hot summer day and the dead of winter.
Mea navis aericumbens anguillis abundat
so, how far is the secret nazi base from Dome C?
They seem to maintain a good sense of humor despite the cold. What do the authors look like?
Analogies don't equal equalities, they are merely somewhat analogous.
However, I think Site C shows promise for imaging sites that are not in the right plane for Hubble to get a look at, or where the long winter night would allow for extended exposures...
Obligatory plug - please check out my online novel
Is this overclocked? It better be. At -85C...
IMAGINE THE POSSIBILITIES!
Stay away from the Norwegian camp....they dug up something in the ice and we've lost contact with them....
Last we heard, one of their sled dogs were running this way with a helecopter following it....
"Leo Fender was in a 'state of grace' when he designed the Stratocaster." -- Paul Reed Smith
I'm apalled that we are polluting Antartica with this radioactive material. What if the phone melts down? This could have devastating consequences for all of Antartica's residents.
paintball
Has to be the most hellish place on the surface of the earth. Dante's Inferno does in fact have the very heart of hell full of darkness and ice, in fact. A more miserable condition than any volcanic brimstone, I'd say.
Could we perhaps see some solid CO2 on the ground as snow? Haha. Probably not, but that would be cool. Punny.
Guys, seriously, this wasn't meant to be informative. It was meant to be Funny. Please mod as such.
Doesn't carbon dioxide sublime/deposit at that temp? I was under the impression that is didn't exist as a liquid at atmospheric pressure.
Okay I'm interested in seeing this jet-fuel stirling engine. How well does it work in extreme cold?
For those of you who may not know much about stirling engines, here's some information.
I remember reading about an Antarctic Linux station and thought it was neet-o back then.
WTF? Over?
Simple solution, just put a Pentium 4 Prescott in there. Keep the whole place nice and toasty.
"It's the height of ridiculousness to say for those 9 lines you get hundreds of millions."
Thanks to the excellent astronomical seeing conditions at Dome C, the Australian scientists started work on their second paper:
"Quasi-Formulaic Investigations into the Space-Time Arrival Calculations of the Zarlanian Horde"
The paper is being rushed to press with journals such as Nature and New Scientist in the hopes of beating the inevitable alien invasion and, thus, enjoying the publicity prior to enslavement and/or annihilation.
"We're pretty excited about this second research opportunity. As soon as we turned on our Dome C equipment and saw the bristling plasma gun turrets from the Zarlanian Horde lead star cruiser, we knew that we had at least 1 more paper opporunity in us," said Rich Godfrey, a previously unmentioned post-doc working on the project.
The research team is taking full advantage of the excellent seeing conditions now, confident that they'll be able to put together a rough draft of the paper shortly before the first scout troops from the Zarlanian Horde arrive.
IronChefMorimoto
want to know more? see ... http://www.scs.cs.nyu.edu/coral/
Not giving him a coat. Poor guy must have frozen out there.
No moving parts to freeze? Can you say Hard Drive? Keyboard? Power Switch?
Last but not least. The user. You got to have some damn heavy mittens for -85C.
The article specifically says that they used solid-state hard drives. The system was operated remotely so I imagine no keyboard was used.
In addition, -85C was only the exterior surface temperature. One computer was installed under the surface with an average operating temperature of -57C. Another experiment was warmed by waste heat from the stirling engine.
You'd think they'd have a cooler word for that...
As someone with myopia, I'd suggest laymen's terms like "20/20" or "20/10" or whatever (what would it be? "20/8") to describe the improved perspicacity available in low turbulence air. [BTW, I'm looking into Lasik and wondering just how good my vision could get...]
Or, you could perhaps express it in terms of
The ultimate, of course, is the Hubble, above the atmosphere. But the transportation and maintenance costs of the Hubble are considerably greater than Dome C.
BTW, nice work, nice web page. Thanks for sharing it.
"Provided by the management for your protection."
My first thought on seeing the map was where the really important sites are - like buried space ships with frozen, morphing monsters and underground pyramids full of aliens. Any fool can take out a secret Nazi base...
Let's try an experiment. You and I each get
$1,000 to buy clothing for our chosen destinations. You hike through the molten lava fields into the active volcano and back out (ha!), and I'll hike the equivalent distance across any part of the south polar shelf. Who's going to be alive when the helicopter comes back?
F = 9/5 * C +32
C = (F-32) * 5/9
Can you tell us about the dramatic events of 17 May 2004?
By 17 May 2004 the AASTINO had worked remotely for 100 days in 2004, and then something went wrong...
The WhisperGen engine has a control panel connected to it using an RS-485 bus running on CAT-5 cable. The control panel contains a microprocessor, and the engine expects to communicate with it regularly (at least once a second). When this communication is interrupted, the engine shuts down and reboots its own microprocessor.
Unfortunately, this is what happened on 17 May. - the engine went into a cycle of rebooting every 40 seconds. Once the engine has stopped, we had a ten hour window in which to try to restart it before the 200AH lead-acid batteries would lose too much capacity and become too cold for a restart (which requires 15A at 24V for about 15 minutes).
During this period we worked feverishly to come up with a solution. Our first priority was to shut down all unnecessary power consumption in the AASTINO - we can do this via a series of Dallas one-wire switches which control power to all the subsystems. A call to the engine manufacturer came up with the suggestion that we wiggle the CAT-5 cable connection - we suspect they forgot that we were over 4000 km away from our engine!
The PC/104 computer was also on the RS-485 bus, and we reasoned that by rewriting the Linux device driver (which we had written in the first place, so we knew what we were doing) we could make the computer impersonate the control panel, and convince the engine that it should keep running. Fortunately, we had a snapshot of the communication traffic between the engine and the control panel from earlier testing in the lab with the manufacturer's MSDOS-based software. But with no hardware available to test our code, we had to modify the driver, send patches over the 2400 baud Iridium link, and rmmod/insmod the driver to try to restart the engine.
All the while, the internal temperature of the AASTINO was plumetting towards ambient, at about -60C. We first modified the driver to allow the link traffic to be analysed, and this confirmed the communication problem with the control panel. After several attempts at generating fake packets from the control panel, punctuated by breaks in the Iridium link and agonizing waits for the system to redial (it is dialout only, controlled by a crontab entry), we were unable to prevent the engine from rebooting.
We watched helplessly as the battery temperatures sank below the minimum threshold for engine restart. Over the next 24 hours we received the occasional connection from the AASTINO computer, but that was all. We are now hoping that the solar panels will be able to recharge the batteries suffiently to re-establish communication before the Dome C station opens for the summer.
Heroic tech team just went there. http://ars.userfriendly.org/cartoons/?id=20040915
what this is all about is polution. if the view ... *sigh*
is like 2.5 times clearer in the antartic, then
we poor suckers are breathing air 250 % more dirty
here... pollution! yes! prolly my great grand
mom hand very good view from the back of her garden
in europe some 90 years ago
Problem: Environmentalists would probably freak out.
Seastead this.
This actually happens quite a lot and is one of the reasons large companies farm off risky things to spinoffs. Typically they wait for the spinoff to flounder AFTER it has sucked in huge amount of external capital and then at the last moment buy everything back for pennies on the dollar.
A good portion of certain companies DSL setups was done this way.
--- I do not moderate.
Read the part on the events of May 17th 2004. This has got to be the coolest troubleshooting situation I've ever heard of.
It would be more impressive if they'd gotten the engine started before the batteries cooled off too much and everything ran down.
But they did get qutie a bit done (installed observability and confirmed the failure mechanism) before the station went dead until spring. Too bad it was too broke to fix in the time available.
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
... the world's newest chip cooler. Coming to an ebay near you!
You can view the health reports (temperature etc.) that that telescope sent back via Iridium here.
There may be other tasties too -- I haven't dug too much.
stirlings are pretty puny by any standards, have moving parts that will wear out and therefore a limited mtbf, are bloody expensive and very prone to any condensation or icing.
I'd have thought peltiers (which the russians used to generate power in space) would have been a much better solution. No moving parts, 200,000 hour mtbf, dirt cheap, compact, and will scale to any desired power out[ut.
Does anyone know why stirlings were used?
Would be most interested to know for a fact.
cheers
http://slashdot.org/~GuyFawkes/journal
At that temperature, CO2 will deposit if it's over a non-reactive substrate. In this context, CO2 in the air perfuses into the H2O ice already present, insinuating itself gradually along with other atmospheric gasses (even though those are still vaporous at that point), and never forms a distinct layer. You can measure an index of trapped CO2 in the regular ice, but that's not as exciting somehow.
Who is John Cabal?
LinuxBIOS can boot from power-up to login prompt in three seconds (half way down the page for 2/15/01). Since Linux is capable of multitasking, they could then run their software while they wait for the CF to mount (probably much quicker than IDE).
This is off-topic, but in html, a link is made by Free gmail invites!. Clicking on "Free gmail invites" would then take you to http://www.goatse.cx.
The 'a' I believe stands for 'anchor', and 'href' for HTTP Reference. Note the '/' before the 'a' in the closing tag, it's important.
I grew up in South Africa, where the major part of the country is above 1000meters above sea level. In the center of the country, the summers are hot (around 20 centigrade at night) and it rains on occasion (humid) and the winters are cold (below zero at night) and absolutely dry.
Because we lived in the countryside, I remember often watching the stars at night and the view is beautiful. What was interesting, and on topic in this case, is that the view of the night sky is much better on a cold winter night than in the middle of summer.
As a professional astronomer, it drives me NUTS when stories like this make it so hard to figure out what they're really talking about. In this case, what kind of seeing, in arcseconds, is achieved and how often. It took me nearly a minute of poking around to find out, and that was really the point of the story.
I can't tell you how many "news" stories about astronomy I've read that left me scratching my head trying to figure out what they were talking about. This IS better -- the information was in the links -- but come on! If you're not telling a professional anything in the lead-in, what are you really telling anyone else? You might as well just issue press releases willy nilly claiming all sorts of crap without any hard numbers.
E.g., why not lead in with something provocative like, "Less than 1/10 an arcsecond achieved in Antarctica, nearly comparable to the Hubble Space Telescope!"
That's quantitative and still understandable and sensational.
Professor of Astronomy, Author of Spider Star & Star Dragon (Tor)
Well, quantitative seeing measurements are usually for the benefits of astronomers, not lay people. You tell us 10 arcseconds, 1 arcecond, or 1/10 arcsecond, and we immediately know the significance of the number (with the complimentary information of the wavelength in question).
In a lot of press releases, you get numbers about what size object could be resolved on the moon, from a mile away, etc., which makes more sense to most laypeople than 20/20 -- which most lay people don't understand anyway. Especially when telescopes blow that away by orders and orders of magnitude.
Professor of Astronomy, Author of Spider Star & Star Dragon (Tor)
... convince the engine that it should keep running.
Reminds me of Bomb #20
What is an "arcsecond"?
An "arcsecond" is a unit of angular measurement. There are 360 degrees in a circle, and 3600 arcseconds in a degree. The full moon is 1800 arcseconds across. A star observed from the best mid-latitude observatories appears to be between 0.5 and 1 arcsecond in diameter. A star observed from Dome C would on average appear to be 0.27 arcseconds in diameter.
How would a telescope at Dome C compare with the Hubble Space Telescope?
The Hubble Space Telescope (HST) has a 2.4 m mirror, and delivers 0.05 arcsecond resolution at visible wavelengths. The best seeing we measured at Dome C was 0.07 arcseconds, however, this figure becomes lower when corrected for the finite size of the outer scale of turbulence (see Tokovinin, PASP, 114, 1156-1166). We don't have enough information yet to accurately determine the correction. While a 2.4 m telescope on the ground can never equal HST's performance, a somewhat larger telescope, say 4m, at Dome C could well produce images of equivalent resolution to HST for about 10% of the time. And in the near-infrared (e.g., the K band at 2.4 microns), the percentage should go up to 50%.
Global warming is neither science, nor politics. It is a religion.
At least I'm not the only one ... I don't know, either. I would guess, though, that it might be something "pre-hardened" against the /. Effect.
Global warming is neither science, nor politics. It is a religion.
I am puzzled why everyone keeps adding "disclaimers" to their posts. Do you imply that you disclaim the liability for your research? Do you imply that being an author somehow makes you less qualified to write about it on Slashdot? Or do you imply that we should not trust your results at all?
May be you mean something completely different? May be you just want to inform us that you wrote the paper and so this post to some small extent results not from the story being objectively important, but from your desire to promote it. If so, then please call it "Disclosure" in the future, because this is what you do - you disclose information about your authorship.
Future Wiki -- If you don't think about the future, you cannot have one.
OK, Columbia Internet or whatever they're called, AJ and Miranda going to the South Pole. This week's userfriendly.org strip.
Bill Stewart
New Fast-Compression-only CPR http://preview.tinyurl.com/dy575ks
How do you get that up there ? (*interesting possibilities*) or are we just talking about pressure based fluid dynamics here ?.
... I live in the tropics ...
Oh, yeah
It was immediately obvious from the very outset to anyone who spent a little while playing around with the math that there would never be any way to make money from this.
Remember that Iridium Outset = 1987. At that time cellular phones were a specialty item used by high-rolling executives, charge per minute were astronomical and coverage patchy. The investment in Iridium didn't seem more dangerous than, say, the development of a new business jet. It was pretty difficult to imagine that in just a few years prices will drop by orders of magnitude and cellular phones will become a fashion item for schoolkids.
They did assume in their business plan that the prices of ground-based competition will drop, but not by that much.
Stop worrying about the risks of nuclear power and start worrying about the risks of not using nuclear power.
..country I ever heard of. They speak English in What?
You should also mention that they need to be complete URLs (including the "http://" bit), and that the trailing slash on the URL is polite ("http://www.goatse.cx/")
Check out my site for past trips to Dome C. Note that it will be the first winterover at Dome C ever, with 8 french and 8 italians.
Can't post much more right now as my connection's been hit by lightning...
Non-Linux Penguins ?
In any case it might be especially useful for detecting polar-orbit debris.
Also, having a data-point on small asteroids that are zipping past the earth might be scientifically interesting as well.
PS: Mercury demential has very different symptoms from ignorance.
Seastead this.
Some countries use Inmarsat for embassy/consular emergency comms, but it needs a pretty good horizon to get a signal if you are far from the equator as the sats are geostationary.
The main mistake of Inmarsat was to discount the growth of GSM roaming which for most people is pretty adequate. It doesn't work everywhere but you would be amazed where it does work (even in Malaysian jungles).