Precision Space Astrometry as a Tool to Find Earth-like Exoplanets

TL;DR

The paper discusses the design and potential of the MAP space mission to detect Earth-like exoplanets around nearby stars using ultra-precise astrometry, leveraging recent technological advances.

Contribution

It introduces the MAP mission concept, detailing its instrumentation and capability to achieve 0.8 microarcsecond precision for exoplanet detection.

Findings

MAP can detect 1 Earth mass planets at 1 AU around nearby stars.

The mission design achieves the required astrometric precision within 1 hour.

MAP could identify targets for future spectroscopic characterization.

Abstract

Because of the recent technological advances, the key technologies needed for precision space optical astrometry are now in hand. The Microarcsecond Astrometry Probe (MAP) mission concept is designed to find 1 Earth mass planets at 1AU orbit (scaled to solar luminosity) around the nearest ~90 FGK stars. The MAP payload includes i) a single three-mirror anastigmatic telescope with a 1-m primary mirror and metrology subsystems, and ii) a camera. The camera focal plane consists of 42 detectors, providing a Nyquist sampled FOV of 0.4-deg. Its metrology subsystems ensure that MAP can achieve the 0.8 uas astrometric precision in 1 hr, which is required to detect Earth-like exoplanets in our stellar neighborhood. MAP mission could provide ~10 specific targets for a much larger coronagraphic mission that would measure its spectra. We argue for the development of the space astrometric missions capable of finding Earth-2.0. Given the current technology readiness such missions relying on precision astrometry could be flown in the next decade, perhaps in collaboration with other national space agencies.