The terrestrial vegetation observed in the Earthshine spectrum: a test for the detectability of vegetation on extrasolar planets

The search for life on extrasolar planets can focus on atmospheric biomarkers. However, the detection of vegetation spectrum, and specially the Vegetation Red Edge constitues another approach. We focus on a test of the detectability of vegetation on Earth seen as a single dot: the detection of vegetation in the spectrum of the global Earth on the lunar surface, or Earthshine. We review the first results obtained by different groups, new ongoing observations and future plans.