Giant starshade or shape-changing mirror could help telescopes find life-bearing planets
BOSTON — When Voyager 1 pivoted back toward Earth from beyond Neptune in 1990, it snapped one of the most famous space pictures: the pale blue dot, with Earth appearing as a lonely speck of light. Astronomers are now designing a new generation of telescopes with hopes of taking a photo of another pale blue dot, this one orbiting a distant star. The proposals offer two contrasting ways of blocking out a distant star’s light, one with a giant shade traveling through space near the telescope and the other with shape-changing mirrors within the telescope.
NASA’s crippled Kepler space telescope has already shown that small rocky planets are common (SN: 4/5/14, p. 15). But Kepler’s data can’t distinguish Earthlike planets from dead ones more like Venus, Mars or something unimagined. On