Spectrum of a Habitable World: Earthshine in the Near‐Infrared

• DOI: 10.1086/503322
• Publication Date: 2006-06-12T16:46:59Z
• Authors: Margaret C. Turnbull; Wesley A. Traub; Kenneth W. Jucks; Neville J. Woolf; Michael R. Meyer; Nadya Gorlova; Michael F. Skrutskie; John C. Wilson
• Keywords: Cirrus; Jupiter (rocket family)

To characterize the spectrum of Earth viewed as an extrasolar planet, we observed spatially integrated near-infrared (0.7-2.4 μm) reflection via dark side Moon (earthshine). After contributions from Sun, Moon, and local atmosphere were removed, resulting was fitted with a simple model reflectivity Earth. The best fit is dominated by above medium-altitude water clouds, lesser high-altitude ice clouds ground. spectral features seen are H2O (six strong band structures 0.7 to 2.0 μm), CO2 moderate-strength 1.4 2.1 O2 (two at 0.76 1.26 several weak CH4 features. Interpreted would confidently conclude that this habitable based on presence bands. Furthermore, simultaneous oxygen methane indicator biological activity. We might also planet geologically active, CO2, water, dynamic (inferred cirrus cumulus clear-air fractions in our fit). This suggests it be valuable for Terrestrial Planet Finder-Coronagraph (TPF-C) mission include spectroscopy capability. On basis present work, suggest future long-term monitoring earthshine allow us discern how globally changes rotation, cloud cover, seasons.