![Earth biosignatures through time and their reflected light spectra. The left subplot shows estimates of Earth’s bulk atmospheric composition through time (advancing from top to bottom), and the figures on the right show the corresponding reflected light spectra considered in this study. Key absorption features for biosignature gases (O3, O2, CH4) and suggested long- and short-wavelength cutoffs are highlighted (as discussed further in Sections 3 and 4). Adapted from National Academies of Sciences, Engineering, and Medicine (2021) and LUVOIR and HabEx Final Reports (LUVOIR Team, 2019; Gaudi et al., 2020). -- [Astrobiology (Journal)]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/08/Wavelength.png?resize=1200%2C719&ssl=1)
[Astrobiology (Journal)] Searching for signs of life is a primary goal of the Habitable Worlds Observatory (HWO). However, merely detecting oxygen, methane, or other widely discussed biosignatures is insufficient evidence […]
Astrobiology (Journal)
Posted inNASA Astrobiology Program
Astrobiology: Fifty Years After Viking: New Special Collection Available Now
Guest edited by Dr. Scott M. Perl (LA-NHM) and Dr. Mary Beth Wilhelm (NASA Ames) To mark the 50th anniversary of NASA’s Viking landings, the journal Astrobiology has published a […]
Posted inMars
The Search for Life and Biosignatures on Mars: A Mars System Science Approach (Atmosphere, Hydrosphere, Cryosphere, Lithosphere, Geologic History)
[Astrobiology (Journal)] The most important quest in Mars exploration is the search for biosignatures. We adopt a Mars System Science approach, calling on information from the atmosphere, hydrosphere, cryosphere, lithosphere, […]
Posted inMars
Biological Validation and Agnostic Experiments For Extant And Extinct Microbial Life Within The Martian Subsurface
[Astrobiology (Journal)] Over the last several decades, investigations of Earth’s subsurface and other extremely low-biomass systems have refined our understanding of the environmental limits of life, driven by methodological advances […]