"Adaptive optics (AO) systems correct for optical wavefront errors introduced by Earth's turbulent atmosphere, turning initially blurry images into intense diffraction-limited concentrations of light. The implementation of AO systems on the world's largest telescopes has revolutionized essentially all areas of astronomy. Instruments that receive a well-corrected beam of light can operate as if observing from space and thus benefit from an order-of-magnitude higher spatial and spectral resolution (see the figure). Given the benefits of working with nonfuzzy images, it may therefore be surprising to learn that one of the most important techniques for finding extrasolar planets, the Doppler radial velocity method, still uses “seeing-limited” observations—that is, measurements obtained without AO correction."
Read the full article at sciencemag.org.