Adaptive optics let scientists peer into other solar systems

In fact, current methods that rely on the Doppler shift only detect the presence of large Jupiter-sized planets that circle not far from their suns. The Extreme Adaptive Optics Planet Finder (ExAOC), planned for the Gemini South Telescope in Cerro Pachon, Chile, however, should let astronomers see large planets farther from their star and with more detail, including mass, radius, temperature, and composition.

The new system will use adaptive optics to measure atmospheric distortion then correct for it by bouncing incoming light off a deformable mirror. But unlike the Keck Telescope in Hawaii that uses 349 actuators to shape a thin sheet of reflective glass, ExAOC will use 3,000 to 4,000 etched-silicon MEMS actuators that can change the shape of the mirror by several microns with accuracies of less than 1 nm. It should correct for atmospheric distortions 10 times better than any current system, according to engineers at Lawrence Livermore National Laboratory, the institution leading the project. When first used in 2009, the ExAOC telescope will be equipped with an IR spectrometer that can detect the heat given of by planets when they form. ExAOC will be installed on a telescope in the southern hemisphere because the southern skies contain more young stars whose planets are easier to detect.