Most powerful telescope system of the future?

[twofish-quant]

Actually astronomers have already combined images from telescopes of various sorts aiming at the same part of the sky from opposite spots in the Earth's orbit, which is a lot longer than 21 km.

With radio yes. Not with optical.

There are two things to worry about. Detail and brightness. You can have extremely detailed images which aren't sensitive to faint objects, or you can have extremely sensitive but somewhat blurry images,

The Hubble telescope was once pointed at the same spot for a week and found 3,000 new galaxies. Theoretically, you could do the same thing for six months and get even better resolution. The law of diminishing returns applies, though.

No you can't. The fact that the telescope has a finite size means that you won't get any better resolution. You will see dimmer and dimmer galaxies, but that's something different.

 

[Zentrails]

With radio yes. Not with optical.

There are two things to worry about. Detail and brightness. You can have extremely detailed images which aren't sensitive to faint objects, or you can have extremely sensitive but somewhat blurry images,

No you can't. The fact that the telescope has a finite size means that you won't get any better resolution. You will see dimmer and dimmer galaxies, but that's something different.

No, you should get slightly better resolution, because of parallax, certainly very small for nearly all other galaxies, but not small for stars in our own galaxies. Combine that with computer enhancement and you should get better resolution - it's effectively like using a Newtonian reflector telescope with a bigger mirror - Earth based optical telescopes are always categorized by mirror diameter and there are telescopes out there now with multiple mirrors that are aimed by computerized coordinated control. I agree that the effect is probably insignificant for a single telescope. If you could combine many telescopes from a variety of orbits around the sun, the effect should be more pronounced.

We might have differing definitions of resolution. All stars that are lightyears away are detected by a single photon over a certain period of time - so there is a limit to the resolution you can get with an optical telescope because of that. I'm talking about objects that are large enough or close enough to have a optically measurable diameter.

The one week Hubble photograph which identified 3,000 new galaxies was more than just a long exposure, simply collecting more photons in a particular region of the sky, IIRC.

And as a bonus you can calculate distances to these stars as well. They can even eliminate noise due to atmospheric scattering by sending particle into the sky and measuring the scatter of the particles, then computer correcting the images. That certainly enhances resolution - and you eliminate one of the advantages of an orbiting telescope.

It occurs to me that the Cobe background study (currently being refined with more and more detail) could be called the best telescope of them all, if you define the power of a telescope as it's ability to detect the farthest away objects. The resolution keeps getting better but it's nothing like the resolution of an optical telescope. It's a radio wave (microwave) detecting telescope, but it works by digitally subtracting the microwaves of known objects.

I spend a lot of time trying to grasp what the COBE backround is really showing us. Not only is it far, far back in time, in a manner of speaking, but the images come from a universe which had a much, much smaller volume than what we think the volume of the universe is today. It's exceedingly difficult to visualize, at least for me.