carotenoids Archives - Astrobiology

Left: Reflectance spectra of photosynthetic organisms on rock, mineral, and snow/ice abiotic surfaces with Archean, Proterozoic, and Modern atmospheric compositions (planetary spectra provided by Anna Grace Ulses, Univ. of Washington). The thick angled lines show the pigment ”edge” features in the spectrum. Right: Top: purple anoxygenic phototrophs with bacteriochlorophyll pigments absorbance and reflectance features at 805-880 nm at 15% planet coverage under an Archean atmosphere with 50% cloud cover. Middle: cyanobacterial microbial mat (oxygenic phototroph) with chlorophyll a absorption at 660-680 nm at 15% coverage under a Proterozoic atmosphere with 50% cloud cover. Note that the 3-D structure of the mat is effective at scattering light to create a ”red edge” feature similar to the vegetation red edge (VRE) shown in the bottom panel. Top two spectra provided by N. Parenteau, unpublished data. -- astro-ph.IM

Astronomy & Telescopes, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Icy Worlds, Imaging & Spectroscopy, Microbiology & Virology, Status Report, Water/Hycean Worlds & Oceanography

Habitable Worlds Observatory Living Worlds Working Group: Surface Biosignatures on Potentially Habitable Exoplanets

by Keith CowingJanuary 15, 2026January 15, 2026

The Habitable Worlds Observatory (HWO) is the first NASA Astrophysics flagship mission with a key science goal of searching for signs of life on rocky habitable exoplanets beyond our solar […]

Lake Eyre --NASA

Analog Studies, Atmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Extremeophiles and Extreme Environments, Habitable Zones, Imaging & Spectroscopy, Plant Biology, Press Release, Sample Return, Tricorders & Sensors, Water/Hycean Worlds & Oceanography

Orbital Biosignature Assay: Lake Eyre

by Keith CowingJanuary 7, 2026January 7, 2026

Editor’s note: As we begin to study worlds in our own solar system that might have life we use our home world as a testbed for the various ways to […]

Platinum replica electron microscope image of the inner membrane of a mammalian cell. Source: Justin Taraska, Ph.D., chief of NHLBI’s molecular and cellular imaging laboratory -- NIH.gov

Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Exploration Gear & Tech, Extremeophiles and Extreme Environments, Fossils & Paleontology, Genomics, Proteomics, Bioinformatics, Imaging & Spectroscopy, Microbiology & Virology, Origin & Evolution of Life, Status Report, Tricorders & Sensors

Membrane-Spanning Molecular Lengths as an Agnostic Biosignature

by Keith CowingMay 27, 2025May 27, 2025

We explore a hypothesis in which the detection of classes of lipid-like molecules with similar abundance-averaged lengths would constitute a biosignature for other worlds.