Abstract

Advances in astronomical observing techniques has led to the discovery of exoplanets (now over 5000) over the past three decades. While NASA's Kepler mission has provided observational evidence that exoplanets are ubiquitous, and placed statistical constraints on the frequency of temperate rocky planets (i.e. potentially habitable worlds) - the discovery and characterization of truly Earth-like exoplanets orbiting Sun-like stars, and the search for signs of life on those worlds, remain significant generational challenges for the astronomical community. The Astro2020 Decadal Survey ("Pathways to Discovery in Astronomy and Astrophysics for the 2020s") recently recommended that NASA initiate a Great Observatories Mission and Technology Maturation Program. The first priority observatory to be matured was recommended by the Decadal to be a large (~6-meter) space-based Infrared/Optical/Ultraviolet telescope with high-contrast imaging capable of spectrally characterizing a "robust sample" (~25) of potentially habitable exoplanets, and to be a transformative facility for general astrophysics (with the goal of launching by the early 2040s). Achieving the scientific goal of the Decadal IR/O/UV space telescope of spectroscopically characterizing a robust sample of the nearest temperate rocky exoplanets orbiting the nearest Sun-like stars has the potential to alter our perceptions of Earth and humanity's place in the universe. I'll discuss some recent science and technology development by the NASA Exoplanet Exploration Program (ExEP) to prepare for exploring options for the Decadal IR/O/UV space telescope.