If we’re lucky, the COROT mission, to be launched December 21, will be the first to detect rocky planets not much larger than the Earth around other stars. We’ve looked at COROT recently, and discussed how it and the Kepler space telescope will use transit methods to find these distant worlds. But as you go beyond Kepler (to be launched in 2008), the need for new technologies becomes apparent, which is why planet-finder designs like New Worlds are so significant.
Now I see that Claude Catala (Observatoire de Paris-Meudon) is proposing a new take on space-borne telescopes for this purpose. Catala suggests a survey that would gather light from literally hundreds of 10-centimeter telescopes working in tandem (COROT itself is built around a single 27-centimeter telescope). These are small instruments, to be sure, and in some ways less impressive than high-end amateur equipment now on the market. But each boasts a wide field of view, roughly 60 times that of the full Moon.
And that helps, because transit detections require monitoring as many stars as possible to find the small percentage aligned properly to Earth. What Catala is thinking is that each of these tiny telescopes could provide interferometry data to a computer aboard the spacecraft. The cumulative effect would be to detect transits over a wide swath of sky. Think of this as a tuned-up Kepler, and a transitional mission between it and later, direct imaging flights like the ESA’s Darwin and, let’s hope, New Worlds.
Canada’s MOST can detect a part per million change in brightness of a star. It’s only 6 inches.
In my ameteur observing, i’ve noted that more can be seen in a 4 inch scope under really dark skies than can be seen from a 10 inch scope in downtown Detroit. It’s very dark in space. MOST was only $10,000,000. Very cheap for a telescope in space.
But, to me, wide field of view is associated with short focal length, not small aperture. So, i’m imagining 1 meter F0.1 scope. Alright. Maybe that is impractical.