Richard W. asks: What are the current/upcoming telescope technologies?

There have been many changes in telescope technologies over the past few years, so I won’t try to hit them all; just the ones that I find fascinating!

Although perhaps not exactly recent, the most widely used technology is the CCD camera. This basically changed the face of astronomy, because now images can be stored, and analyzed, on computers.

One CCD camera in particular is MegaCam on the Canada-France-Hawaii Telescope. This camera is one of the largest astronomical CCD mosaics in the world, consisting of 36 2048 × 4612 pixel CCDs, with a 1-degree by 1-degree field-of-view. This means it can fit the full moon and more in one frame! It is the equivalent of a 340 megapixel camera. Pretty good, if you ask me. I actually use data from this camera, and we have found thousands of asteroids that have never been seen before.

Another technique currently being used is adaptive optics, which reduces distortions in an image caused by turbulence in the atmosphere (which is what makes stars twinkle!). A sensor measures the distortions on millisecond timescales, then a computer calculates the optimal mirror shape to reduce the distortions. The mirror, which is deformable, is shaped accordingly. Pretty cool stuff.

One popular upcoming technology is the use of interferometry – using two or more smaller telescopes, separated by a certain distance, to get a bigger field-of-view. This is most widely associated with radio telescopes, like the Very Large Array in New Mexico, but is now being used at different wavelengths. One such idea was Constellation X, which was going to be an X-ray observatory with 4 telescopes placed in Earth’s orbit. This one has since been changed to the International X-ray Observatory, and sounds like it will only be one telescope.

Another example of this is PanStarrs – an optical telescope that will use 4 smaller telescopes to get a panoramic view of the sky. One of these telescopes is built, and they intend to have the other three built and working by 2012. It’s primary mission is to detect potentially hazardous asteroids in near-Earth space.

The bigger the mirror, or light bucket, the fainter we can see. That’s the motivation behind the Thirty Meter Telescope. Yup, that means the main mirror will be 30 meters (or about 100 feet) across. I don’t know what else to say about this except that it’s frickin’ cool.

Having large mirrors poses a problem, however. They just can not be made at high quality over a certain size. To address this, scientists have come up with two solutions: combining a bunch of smaller mirrors (usually hexagonal in shape), and liquid mirrors. This works by rotating a small layer of liquid so it makes a parabolic shape. The problem here is the mirror cannot be tilted, but you don’t have to worry about cutting yourself on all that glass. Come up with a method to tilt one of these babies, and you’re golden.

I know many of you are waiting on me to answer the string theory question…I admit that I’ll probably avoid that for a while, but will get to it eventually! I’m trying to figure out how to discuss it with my friends.