Are we alone in the Universe

Are We Alone in the Universe?

Does life exist on other planets, and if so, how do we know what to look for? Identifying and understanding the necessary ingredients for a planet to support life is one of NASA’s greatest science goals. By studying ways that a planet responds to its surrounding environment, SEEC researchers are pioneering methods to detect life on other worlds. For example, life on Earth has evolved with the planet’s environment, producing changes in the atmosphere called "biosignatures," telltale signs that the planet supports life. Oxygen produced through photosynthesis is considered modern Earth’s primary biosignature. Different planets may have different types of dominant biosignatures, such as biogenic methane and organic haze. In tandem with considerations of possible biosignatures, it is also critical to consider biosignature “false positive” biosignatures generated by abiotic processes to determine how to distinguish them from true signs of life.

Studies of biosignatures must consider how life both acts on and is impacted by its environment. Thanks to a diverse set of scientific expertise and cutting-edge modeling tools, SEEC research can tackle these problems from an interdisciplinary perspective, examining how possible biosignatures can be affected by a planet’s atmospheric, oceanic, climatic, stellar, geological, and biological systems. For example, biosignatures can be impacted by the star a planet orbits. Stars with different ultraviolet radiation levels will cause different chemical makeups of planets’ atmospheres, and different colors of stars could drive the evolution of different vegetation pigments on a planet’s surface.

Related Researchers

Vladimir Airapetian, Giada Arney, Shawn Domagal-Goldman, Nancy Kiang, Ravi Kopparapu, Avi Mandell, Elisa Quintana, Tom Barclay, Melissa Trainer, Geronimo Villanueva

Related SEEC Projects

  1. Arney et al. - "Atmos: Studies of Exoplanet Atmospheres Enabled by a Versatile 1-D Photochemical-Climate Model"
  2. Kiang et al. - "Land Planets: Foundations for Understanding the Distribution of Surface Habitability and Life Inside the Habitable Zone"
  3. Kopparapu et al. - "Determining the Atmospheric Composition and Rotation Rates of Habitable Zone M-dwarfs Planets with Thermal Phase Curves and Transit Spectra"
  4. Quintana et al. - "Where to Search for Habitable Worlds"
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