Two different types of masks to be used in NASA's upcoming Wide-Field Infrared Survey Telescope, or WFIRST, coronagraph instrument, are pictured. At left, the "hybrid Lyot" mask has carefully designed metal and "dielectric" layers, but without a microscope it looks like a barely visible pinprick of a dot on glass. At right is the "shaped pupil" mask, which is a few centimeters across and consists of highly reflective mirror regions interspersed with regions of black silicon. This silicon surface treatment absorbs nearly all incoming light.
Both types of masks are made at the Microdevices Laboratory at NASA's Jet Propulsion Laboratory. They will fly together on the WFIRST coronagraph, enabling it to directly see and spectrally characterize exoplanets without being overwhelmed by light from the host star.
WFIRST is managed at Goddard, with participation by NASA's Jet Propulsion Laboratory in Pasadena, California, the Space Telescope Science Institute in Baltimore, the Infrared Processing and Analysis Center, also in Pasadena, and a science team comprised of members from U.S. research institutions across the country.
For more information about NASA's WFIRST mission, visit http://www.nasa.gov/wfirst.