Looking for a Mirror, NY Times
"The challenges to photographing a mirror Earth are daunting, but not insurmountable. A small rocky planet is a dim mote of dust lost in the glare from a thermonuclear fireball we call a star. For every photon of planetary light that goes into making a picture, 10 billion stellar photons must first be filtered out; remarkably, researchers have already devised several ways to do this. All that the planet-hunters really need to find the mirror Earths is a big mirror, high above the Earth's blurring atmosphere -- a space telescope large enough to gather the faint light of Goldilocks worlds around a sizable sample of stars."