Enabling High-Resolution Imaging and Spectroscopy of an Exoplanet by Use of the Solar Gravity Lens

This chapter documents key scientific and engineering findings from a two-year Phase 2 NASA Innovative Advanced Concepts (NIAC) project to evaluate the use of our sun’s gravitational field as a multimillion-kilometer-diameter lens to image exoplanets in other star systems with up to megapixel resolution. Incident light onto the Solar Gravity Lens (SGL) comes to a focus at a distance of 548 AU (astronomical units) from the sun and has maximum light amplification of ≈10¹¹ coupled with angular resolution of ≈10^–10 arcsec for 1-μm wavelength light. A micro/nanospacecraft with a 1-m-aperture optical telescope in the SGL’s focal region can build an image of an exoplanet at a range of 30 pc (parsec) (98 light-years) with ≈20-km-scale resolution of its surface in a year of integration time. This revolutionary ability would be sufficient to observe seasonal changes, oceans, continents, and surface topography on alien exoplanets and large moons. Mission and spacecraft requirements, plus a concept of operations for getting to the SGL within a human lifetime and sending image data back to Earth, are the main focus of this chapter.