2001/08/01 by Eric B. Ford, E. B. Ford, Sara Seager +3 · 12 citations
Environmental Science · Physics and Astronomy · #Astro and Planetary Science #Isotope Analysis in Ecology #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1038/35091009
published as Nature, vol. 412, p.885-887, August 30, 2001 · Published in Nature. 9 pages including 3 figures
crossref issued 2001/08/01 · crossref published 2001/08/01 · crossref published-print 2001/08/01 · openalex publication_date 2001/08/01 · arxiv created 2001/09/04 · crossref created 2002/07/26 · arxiv updated 2015/06/24 · crossref deposited 2023/05/17 · openalex created_date 2025/10/10 · crossref indexed 2026/04/17 · openalex updated_date 2026/07/28
The detection of massive planets orbiting nearby stars has become almost routine, but current techniques are as yet unable to detect terrestrial planets with masses comparable to the Earth's. Future space-based observatories to detect Earth-like planets are being planned. Terrestrial planets orbiting in the habitable zones of stars-where planetary surface conditions are compatible with the presence of liquid water-are of enormous interest because they might have global environments similar to Earth's and even harbor life. The light scattered by such a planet will vary in intensity and colour as the planet rotates; the resulting light curve will contain information about the planet's properties. Here we report a model that predicts features that should be discernible in light curves obtained by low-precision photometry. For extrasolar planets similar to Earth we expect daily flux variations up to hundreds of percent, depending sensitively on ice and cloud cover. Qualitative changes in surface or climate generate significant changes in the predicted light curves. This work suggests that the meteorological variability and the rotation period of an Earth-like planet could be derived from photometric observations. Other properties such as the composition of the surface (e.g., ocean versus land fraction), climate indicators (for example ice and cloud cover), and perhaps even signatures of Earth-like plant life could be constrained or possibly, with further study, even uniquely determined.