MoonLITE: a CLPS-delivered NASA Astrophysics Pioneers lunar optical interferometer for sensitive, milliarcsecond observing

MoonLITE (Moon Lunar InTerferometry Explorer) is a submitted Astrophysics Pioneers proposal to develop, build, fly, and operate the first separated-aperture optical interferometer in space, delivering sub-milliarcsecond science results. MoonLITE will leverage the NAS Commercial Lunar Payload Service (CLPS) to deliver an optical interferometer to the lunar surface, enabling unprecedented discovery power by combining high spatial resolution from optical interferometry with deep sensitivity from the stability of the lunar surface. Following landing, the CLPS-provided rover will deploy the pre-loaded MoonLITE outboard optical telescope 100 meters from the lander’s inboard telescope, establishing a two-element interferometric observatory with a single deployment. MoonLITE will observe targets as faint as 17th magnitude in the visible, exceeding ground-based interferometric sensitivity by many magnitudes, and surpassing space-based optical systems resolution by a factor of 50×. The capabilities of MoonLITE open a unique discovery space that includes (1) direct size measurements of the smallest, coolest stars and substellar brown dwarfs, (2) searches for close-in stellar companions orbiting exoplanethosting stars that could confound our understanding and characterization of the frequency of Earth-like planets, (3) direct size measurements of young stellar objects and characterization of the terrestrial planet-forming regions of these young stars, (4) measurements of the inner regions and binary fraction of active galactic nuclei, and (5) a probe of the very nature of spacetime foam itself. A portion of the observing time will also be made available to the broader community via a guest observer program. MoonLITE takes advantage of the CLPS opportunity to place an interferometer in space on a stable platform – the lunar surface – and delivers an unprecedented combination of sensitivity and angular resolution at the remarkably affordable cost point of Pioneers.