Nice article at MSNBC about the challenges and opportunities in discovering a habitable planet outside our solar system - an twin to our Earth.
""So far we've found Jupiters and Saturns, and now our technology is becoming good enough to detect planets smaller, more like the size of Uranus and Neptune, and even smaller," said one of the top planet hunters on this world, Geoff Marcy of the University of California, Berkeley.
Marcy, Boss and other scientists are optimistic that within the next five or so years headlines will be splashed with news of a near twin of Earth in another star system."
The article also discusses and explains the two techniques of planet discovery (the wobble and the transit methods) and the optimism pervailing the field as new space imaging obervatories bring new technology to the chase, such as the ESA's COROT satellite(already in orbit) and NASA's upcoming Feb. 2009 Kepler mission. Also on tap for the future will be the Webb telescope scheduled for a 2013 launch. Astronomers have discovered several planets at the edge of the habitable zone (where the planet's temperature would be within the bounds acceptable for life as we know it) of an alien star, but not yet one quite in the sweet spot, but researchers beleive it will just be a matter of time.