Mij Adyaw wrote:
How will the Terrestrial Planet Finder mission locate new planets? Is it
some type of new space telescope?

It'll be a space-based long baseline interferometric telescope,
working in the infrared band. The 'scope will be tailored for
selectively blocking the overwelming light from a star in order to be
able to detect the vastly less bright light from small planets on orbit
nearby.

In order to image a planetary disc at such small angular size the
instrument must have an enormous light collecting aperture. A single
objective mirror of such size will be impossible, so the aperture will
be created synthetically by having several smaller independent
telescopes which will systematically combine their images by wave
interference to create a high resolution picture.

Huge synthetic apertures are already in use commonly for radio
observatories, and lately a few optical & infrared interferometers have
been built. The Very Large Array is the most famous such radio
telescope with an effective aperture of several miles, and the twin
Keck optical telescopes on Hawaii create an aperture of about 200 feet.


-Mark Martin