Imaging a habitable planet at Alpha Centauri with a small space telescope

In 1990, at the request of Carl Sagan, Voyager 1 turned and took a picture of Earth from a distance of 6 billion kilometers. This produced the famous "pale blue dot" image of our planet. Several mission concepts are being studied to obtain similar images of Earth-like exoplanets (exo-Earths) around other stars. It is commonly thought that directly imaging a potentially habitable exoplanet requires telescopes with apertures of at least 1 meter, costing at least $1B, and launching no earlier than the 2020s. A notable exception to this is Alpha Centauri (A and B), which is unusually close for a Sun-like star. A ~30-45cm visible light space telescope equipped with a modern high performance coronagraph is sufficient to resolve the habitable zone at high contrast and directly image any potentially habitable planet that may exist in the system.

Dr. Belikov will describe the challenges involved with direct imaging of Alpha Centauri planetary systems with a small telescope and how new technologies currently being developed can solve them. He will also show examples of small coronagraphic mission concepts currently being developed to take advantage of this opportunity, and in particular a mission concept called "ACESat: Alpha Centauri Exoplanet Sattellite" submitted to NASA's small Explorer (SMEX) program in December of 2014.

Speaker: Ruslan Belikov, NASA Ames