Recent advances in astronomical observations have found a significant number of extrasolar planets that can sustain surface water, and the search for extraterrestrial life on such planets is gaining momentum. A team of astrobiologists has proposed a novel approach for detecting life on ocean planets. By conducting laboratory measurements and satellite remote sensing analyses, they have demonstrated that the reflectance spectrum of floating vegetation could serve as a promising biosignature. Seasonal variations in floating vegetation may provide a particularly effective means for remote detection.
Astronomical surveys have discovered nearly 6,000 exoplanets, including many habitable planets, which may harbor liquid water on their surfaces. The search for life on such planets is one of the most significant scientific endeavors of this century, with direct imaging observation projects currently under development.
On Earth-like planets, the characteristic reflectance spectrum of terrestrial vegetation, known as “vegetation red edge,” is considered as a key biosignature.