Disentangling the Hemispheres of Teegarden’s Star b with LIFE

Abstract Teegarden’s Star is one of the most promising targets for the first observations of LIFE as a nontransiting rocky planet with similar bulk properties to the Earth and a relatively quiescent M dwarf host star. We use LIFEsim, a software developed by the LIFE team based in ETH Zurich, along with thermal emission maps obtained from a suite of three-dimensional global climate model simulations, to explore the sensitivity of LIFE to the observation geometry. We find that 3 days of observation in broad band would be enough to disentangle the hemispheres of the planet with a 1 σ or 3 σ confidence level with a baseline or optimistic scenario, respectively. Doing the same for a fast rotator in the habitable zone of a G-class star would be prohibitively challenging. Given enough observation time, the sensitivity of LIFE may allow some spatial resolution of Teegarden’s Star b to be achieved, which may directly link to the presence of water clouds and therefore an active hydrology.