As our knowledge of the resilience of life in extreme conditions on Earth grows, it opens up the possibility for new places to search for life beyond the Solar System. Cataloging the biomarkers of organisms from unique and extreme environments on Earth will likely enhance the ability to identify signs of life on other worlds. The cover of this issue shows an artists' rendition of new work focused on the identification of ice-dwelling bacteria and algae on cold exoplanets and exomoons via their color spectra. The work measured the pigment spectral signatures of 80 different organisms to build a reference catalogue for future characterization of directly observed worlds beyond our Solar System. The depicted hypothetical icy Earth-like exoplanet is covered in the types of strains of cold-loving bacteria that occupy Earth's frozen landscapes. Though we do not expect the spectra of terrestrial psychrophilic strains to provide a perfect spectral match with such hypothetical organisms on other worlds, similarities in the environmental conditions of icy exoplanets—low temperatures, low concentrations of nutrients and carbon sources, enhanced dryness, increased radiation—may have led to a common set of environmentally driven physiological adaptations and pigments of carbon-based life that could be recognized spectrally throughout the Universe.
More info about this work: https://news.cornell.edu/stories/2022/03/tint-life-color-catalog-built-find-frozen-worlds