Want to build a starshade to spot Earth-like worlds around other stars? Start with a Hubble-like telescope a few million miles from Earth. Add a 30-meter wide disk with petal-like extensions, separated by 10,000 miles from the telescope. Watch what happens next.
Using lasers, the two parts would line up, with the star shade just blocking out the light from a nearby star from the center of the telescope’s view. Calculated mathematically to throw away the light from the star but keep the light from any planets it held (this is the “occulting” part of the occulted), the device would be able to detect planets smaller than Earth orbiting stars within 35 light years of Earth, Cash and his colleagues calculate. The key is the petal shape of the shade, which scatters starlight from the telescope’s view.