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Purple archaea may have played a crucial role in the early life forms on Earth, according to a study from 2018. Scientists suggest that before Earth was filled with oxygen, these bacteria used a molecule called retinal to photosynthesize and potentially thrive on the planet’s surface. The lead author of this paper was Shiladitya DesSarma, a molecular biologist at the University of Maryland.
Recent research has expanded our understanding of potential life forms that could have existed on Earth in its early days. By collecting spectral data on 20 species of purple bacteria from various environments such as marshes and deep-sea hydrothermal vents, scientists have created a collection of light signatures. These patterns can be used to model how reflected light might appear on a distant planet, providing valuable information for other researchers to use in their projects. This database is now publicly available for others to access and utilize in their own studies.
Astronomers use biosignatures such as the color of a planet’s surface to search for signs of life on other planets. Reflected light spectroscopy is often used for this purpose, but current telescopes are limited in their capabilities. For example, the James Webb Space Telescope can only detect biosignatures in an exoplanet’s atmosphere and cannot measure reflected light from the planet’s surface. Edward Schwieterman, an astronomer at the University of California Riverside, emphasizes this limitation when discussing the importance of future space telescopes that can detect reflected light from planets’ surfaces.
