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Summary: Astronomy with High Contrast Imaging
C. Aime and R. Soummer (eds)
EAS Publications Series, 8 (2003) 1724
DETECTING THE TERRESTRIAL VEGETATION WHILE
OBSERVING EARTH AS A SINGLE DOT
L. Arnold1, S. Gillet1, O. Lardi`ere1, P. Riaud2 and J. Schneider3
Abstract. Spectroscopic observations of the Earthshine allowed us to
make a relative measurement of the integrated Earth reflectance spec-
trum in which the terrestrial vegetation signature around = 700 nm
has been detected. Therefore we conclude that the terrestrial vege-
tation, and thus terrestrial life, can be detected remotely when the
Earth is seen as a single dot. We also conclude that vegetation can
be detected on an extrasolar Earth-like planet, if a spectral resolution
around 50 is available.
1 Introduction
When future space missions like ESA Darwin (LŽeger et al. 1996) or NASA TPF
(Angel & Woolf 1997; Beichman et al. 1999) will deliver their first low resolution
spectrum of an Earth-like extrasolar planet, it is possible that we will look for
spectral signatures able to unveil the possible presence of life on this planet.
Spectral biosignatures can be of two kinds. A first type consists of biological
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