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Space Science

NASA's Giant Pinhole Camera 29

Posted by CmdrTaco
from the intergalactic-porn dept.
Cecil writes "The University of Colorado at Boulder has come up with an interesting proposal, and NASA has decided it has enough merit to give it funding. They're developing what is in essence a pinhole camera where the pinhole is 30 feet wide, and the "film" is tens of thousands of miles away. The "New Worlds Imager" as it is called, may eventually have enough resolution to get visual images of extrasolar planets as small as Earth's moon around stars 100 light years away, and would be able to search them for the key signs of life-as-we-know-it, like oxygen, water, and ozone. Other ideas that NASA will be developing include a lunar space elevator and magnetized beam plasma propulsion."
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NASA's Giant Pinhole Camera

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  • by JCMay (158033) <JeffMayNO@SPAMearthlink.net> on Monday October 04, 2004 @02:38PM (#10432344) Homepage
    The NEI doesn't seem to have any form of magnification; so we'll have a VERY SMALL picture of something VERY FAR away?
    • Re:Magnification? (Score:2, Informative)

      by Critter92 (522977)
      "A spacecraft equipped with a telescope would trail tens of thousands of miles behind the starshade to collect and process the light." How about reading the article (all 297 words) before posting?
    • Define small?

      And anyway, its better than what we've got now, which is practically nada ..
    • Re:Magnification? (Score:4, Informative)

      by Profane MuthaFucka (574406) <busheatskok@gmail.com> on Monday October 04, 2004 @02:51PM (#10432485) Homepage Journal
      Magnification of a telescope is figured by dividing the focal length of the objective by the focal length of the eyepiece. The type of objective doesn't matter, just it's focal length.

      So here, we've got a focal length of 10,000 miles. At the eyepiece end, the article talks about a telescope being mounted there. That telescope would be for all intents and purposes an eyepiece. Don't know what the focal length of that would be, but it would be a very small fraction of the 10,000 miles, making the final magnification of the telescope very large.

      • IANAP but I just can't see how this will work. Imagine a hubble size telescope (still relatively tiny in the scheme of things here) staring at the "pinhole", a couple hundred foot wide hole TEN THOUSAND miles away....What's it going to get, like 10 photons a second or something ridiculous?? Therefore, I would tend to think the exposure times required to create any kind of meaningful image using this scheme would be insanely long....like...weeks. How can you possibly image a planet like earth orbiting its st
        • That's another good question about this, and I think your description of the problem is right on the money. The f/ratio of this thing is going to be astronomical (pun intended).

          On the other hand, the targets it's supposed to look at are bright, and this might not be such a problem if they use extraordinarily sensitive detectors. I know that on Earth, the reason telescopes are getting so much larger is not really for their light gathering ability as for their resolving power. Before adaptive optics, there w
      • Re:Magnification? (Score:3, Informative)

        by John Hasler (414242)
        > So here, we've got a focal length of 10,000
        > miles.

        No you don't. A pinhole doesn't focus.

        Forget the "pinhole camera" red herring. This is not a camera or telescope of any kind. As the article says, it is a _starshade_. The angular diameter of the hole from 10,000 miles back is not much larger than the angular diameter of a planet 100 light-years away. Thus viewing the planet through the hole from 10,000 miles back blocks out the light of the star the planet is orbiting.

        It's sort of the inver
  • by El (94934)
    A pinhole camera, also known as camera obscura, or "dark chamber", is a simple optical imaging device in the shape of a closed box or chamber. So... where are they getting this 10,000 mile long "closed box or chamber"?
    • Re:Huh? (Score:5, Informative)

      by Profane MuthaFucka (574406) <busheatskok@gmail.com> on Monday October 04, 2004 @02:48PM (#10432457) Homepage Journal
      The dark box isn't necessary if you can restrict the light getting to the film some other way. The article mentioned that the detector would be attached to a telescope, so that would prevent light entering from any place other than the pinhole lens.

      Most large telescopes don't have tubes either, since they aren't strictly needed, and they weigh a lot. See the photo of the scope at: http://gemini.physics.ox.ac.uk/photos/geminin-tele scope-lr.gif [ox.ac.uk] or at http://www.apo.nmsu.edu/Site/3.5m_Images/telescope 06.JPEG [nmsu.edu]
    • Re:Huh? (Score:3, Informative)

      by Smidge204 (605297)
      Obviously it does not NEED to be enclosed. The point being that the shade will block most of the light entering the telescope coming from whatever direction the scope is looking. by blocking this "ambient noise" you can get a better image of what you are aiming at.

      The reason fro the "enclosed box" is, with a traditional camera, you also have to worry about ambient light from all directions exposing the film. Using a telescope automatically eliminates most of this problem, and in space there isn't much ambi
    • The box exists to exclude light from contaminating the image created from the pinhole.

      I suppose they'll have to come up with an alternative means of separating the light from the lens and stray light reaching the trailing spacecraft. (From the article)
  • by G4from128k (686170) on Monday October 04, 2004 @02:48PM (#10432466)
    Onc can do similar observations with inverse optics using asteroid occultations [asteroidoccultation.com]. I suppose one could create an artificial asteroid and watch as it passes in front of stars as it orbits or create a detector satellite with an ion engine that visits occultation zones between selected stars and satellites.
  • by Picass0 (147474) on Monday October 04, 2004 @03:19PM (#10432904) Homepage Journal
    You hold the film and go stand back.

    Farther.

    Farther.

    Farther!

    Farther!!

    Farther!!!
  • Yeah, right (Score:5, Funny)

    by swillden (191260) * <shawn-ds@willden.org> on Monday October 04, 2004 @03:30PM (#10433068) Homepage Journal

    There's no way this is going to work. I mean, how the hell are they going to lift into space a pin big enough to poke a 30-foot hole. Where are they even going to *find* a pin that big?

    Gotta be the most hare-brained scheme ever. Sheesh.

  • by Jesrad (716567) on Monday October 04, 2004 @03:37PM (#10433170) Journal
    I think the correct name for that is magnetohydrodynamics. It's been researched since the late 60s in various countries (US, France, Russia, and a couple others I think), but it is rumoured that only the US ended up having an applicable, working technology.

    Cue to the rumours of Aurora and B2 making use of this to attain crazy hypersonic velocities...
  • Time to submit my vinegar and baking soda rocket fuel formula!
  • by tm2b (42473)
    Let's get NASA out of the business of basic space access and back into the basic research without economic incentive that wouldn't be done otherwise.

    Ferrying people and objects to space should be a commercial [scaled.com] or military [csbaonline.org] activity, instead of NASA trying to be all things to all people

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