The LUCAS experiment: Spectroscopy of Earthshine in Antarctica for detection of life

D. Briot (1) , L. Arnold (2) , S. Jacquemoud (3) , J. Schneider , A. Agabi (4) , E. Aristidi (5) , J. Berthier (6) , E. Bondoux (4) , Z. Challita (7) , D. Petermann , C. Pouzenc (8) , P. Rocher (6)

1 OP - Observatoire de Paris - Site de Paris
2 OHP - Observatoire de Haute-Provence
3 IPGP - Institut de Physique du Globe de Paris
4 LAGRANGE - Joseph Louis LAGRANGE
5 LUAN - Laboratoire Universitaire d'Astrophysique de Nice
6 IMCCE - Institut de Mécanique Céleste et de Calcul des Ephémérides
7 LAM - Laboratoire d'Astrophysique de Marseille
8 Observatoire Sirene

So as to prepare future observations of terrestrial extrasolar planets liable to shelter life, we attempt to detect the life on the Earth seen as a dot. We use the Moon Earthshine, in which any place reflects the totality of the enlightened part of Earth facing the Moon. Observing from OHP and from ESO, we detected terrestrial chlorophyll in the near infrared, the so-called Vegetation Red Edge, and this detection is larger when forests are present than when an ocean is mainly visible from the Moon. Only if observations are made from a high latitude location, and at some moments in the year, Earthshine can be observed during a large part of the day. During these long observing windows, different “landscapes" are facing the Moon. So the Earthshine corresponding to various parts of our Earth could be studied. Preliminary testing observations have been made at Concordia since the first winterover campaign and the LUCAS experiment has been set up.

Domaines: Astrophysique [astro-ph]

D. Briot, L. Arnold, S. Jacquemoud, J. Schneider, A. Agabi, et al.. The LUCAS experiment: Spectroscopy of Earthshine in Antarctica for detection of life. 3rd ARENA Conference: An Astronomical Observatory at CONCORDIA (Dome C, Antarctica), 2009, Frascati, Italy. pp.361-365, ⟨10.1051/eas/1040050⟩. ⟨hal-02481902⟩