NASA's Giant Pinhole Camera 29
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."
Magnification? (Score:3)
Re:Magnification? (Score:2, Informative)
Re:Magnification? (Score:2)
And anyway, its better than what we've got now, which is practically nada
Re:Magnification? (Score:4, Informative)
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.
Re:Magnification? (Score:2)
So what do you think of the theoretical limits of resolution? 30 feet doesn't seem to be much of an objective lens for what they are proposing. I would think that diffraction effects would wipe out whatever resolution gains you would
Re:Magnification? (Score:4, Informative)
The purpose of the shade is to null out the light from the star without affecting the light from the planet. The shade is extremely effective at doing this, and doing it in a way that is insensitive to wavelength.
I'm not sure they need a hole; using the edge of a large disk should also work.
Re:Maybe I'm missing something. (Score:3, Interesting)
Re:Maybe I'm missing something. (Score:2)
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)
> 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
Huh? (Score:2)
Re:Huh? (Score:5, Informative)
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-tel
Re:Huh? (Score:3, Informative)
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
Re:Huh? (Score:2)
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)
Inverse Pinhole: Occulation (Score:5, Interesting)
OK, I'll hold the part with the pinhole... (Score:4, Funny)
Farther.
Farther.
Farther!
Farther!!
Farther!!!
Yeah, right (Score:5, Funny)
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.
Re:Yeah, right (Score:1)
Here's your big needle [nasa.gov].
Re:Yeah, right (Score:2)
Magnetized beam plasma propulsion ? (Score:3, Informative)
Cue to the rumours of Aurora and B2 making use of this to attain crazy hypersonic velocities...
Re:Yet again, NASA wastes taxpayers $$$s (Score:1)
Re:Yet again, NASA wastes taxpayers $$$s (Score:1)
Re:Yet again, NASA wastes taxpayers $$$s (Score:1)
Re:Yet again, NASA wastes taxpayers $$$s (Score:2)
Rocket Fuel Proposal (Score:2, Funny)
Re:Rocket Fuel Proposal (Score:1)
I was thinking along the lines of a very large amount of Match Heads balled up in Aluminum Foil.........
Weeeee
Excellent (Score:2)
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