Starshades and Direct Observation of Exoplanets
When: April 6, 2010 2:30PM PDT
The last ten years have seen truly amazing strides towards understanding the nature of exoplanetary systems. But the techniques that have been so productive at discovering planets are highly limited in what they can tell us about their natures. For that we will need direct imaging and spectroscopy. When we turn the full suite of astronomical instruments, including photometry, spectroscopy and polarimetry on exoplanets we will be able to analyze atmospheres and surfaces and search for unambiguous biomarkers. Starshades, or external occulters as they are more formally known, can suppress light from the central stars and reveal exoplanets into the Habitable Zone. I will review how starshades work, the status of their technical development and how well they can advance observational astrobiology. In particular, I will show how coordinated use of starshades with the James Webb Space Telescope can allow us to find and analyze Earth twins in the coming decade at a price that NASA can afford.