Table 5.

Surface Biosignatures and Related Information

Biosignature	Visible-NIR band center, μm	Visible-NIR band interval, cm−1	Biogenic source	Abiogenic false positive
Terrestrial vegetation red edge	0.67–0.76 (a sharp slope between visible absorbance and NIR scattering)	14925–13160	Photosynthesis: “red edge” due to sharp lack of absorption in the NIR by chlorophyll a	None on Earth
Carotenoids, retinal and other biological pigments	0.40–0.50, 0.53–0.63, and absorption over other narrow wavelength ranges	Aromatic C-H 3000–3000	Photoprotective, phototrophic, or photoreactive and accessory pigments	Future research
		Schiff base compounds (i.e., R2C = NR′ [R′ ≠ H]) 1620–1700 and others
Chirality or circular polarization	Dependent on pigment	—	Biological cell molecular structure	Future research