Observing the Earth as an exoplanet with LOUPE, the Lunar Observatory for Unresolved Polarimetry of Earth

Abstract

The detections of small, rocky exoplanets have surged in recent years and will likely continue to do so. To know whether a rocky exoplanet is habitable, we have to characterise its atmosphere and surface. A promising characterisation method for rocky exoplanets is direct detection using spectropolarimetry. This method will be based on single pixel signals, because spatially resolving exoplanets is impossible with current and near-future instruments. Well-tested retrieval algorithms are essential to interpret these single pixel signals in terms of atmospheric composition, cloud and surface coverage. Observations of Earth itself provide the obvious benchmark data for testing such algorithms. The observations should provide signals that are integrated over the Earth's disk, that capture day and night variations, and all phase angles. The Moon is a unique platform from where the Earth can be observed as an exoplanet, undisturbed, all of the time. Here, we present LOUPE, the Lunar Observatory for Unresolved Polarimetry of Earth, a small and robust spectropolarimeter to observe our Earth as an exoplanet.

14 pages, 3 figures, submitted in special Issue of Planetary and Space Science on Scientific Preparations for Lunar Exploration

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Cited by in corpus (8)

• Back to the Moon: The Scientific Rationale for Resuming Lunar Surface Exploration
• Blue, white, and red ocean planets - Simulations of orbital variations in flux and polarization colors
• Spectral and Temporal Variability of Earth Observed in Polarization
• Colors of an Earth-like exoplanet -- Temporal flux and polarization signals of the Earth
• LOUPE: Observing Earth from the Moon to prepare for detecting life on Earth-like exoplanets
• Effect of multiple scattering on the Transmission spectra and the Polarization phase curves for Earth-like Exoplanets
• A snapshot full-Stokes spectropolarimeter for detecting life on Earth
• Ocean signatures in the total flux and polarization spectra of Earth-like exoplanets