An international collaboration by scientists has created a catalogue of signatures of life that astrobiologists could use to hunt for signs of habitation throughout the cosmos.
The signatures all come from simple organisms found on Earth that could have analogues elsewhere in space.
Lisa Kaltenegger from Cornell University’s Institute for Pale Blue Dots said, “This database gives us the first glimpse at what diverse worlds out there could look like. We looked at a broad set of life forms, including some from the most extreme parts of Earth.”
The NASA Ames Research Center was heavily involved in the project, which has been described in a paper entitled “Surface Biosignatures of Exo-Earths: Remote Detection of Extraterrestrial Life.”
If any of the organisms included in the database were dominant on another world, their pigmentations in the atmosphere could be used to identify those worlds as having life, as well as to identify what kind of life it might be.
As it is explained in the paper, “Much of the history of life on Earth has been dominated by microbial life. It is likely that life on exoplanets evolves through single-celled stages prior to multicellular creatures. Here, we present the first database for a diverse range of life — including extremophiles (organisms living in extreme conditions) found in the most inhospitable environments on Earth — for such surface features in preparation for the next generation of telescopes that will search for a wide variety of life on exoplanets.”
The amazing array of life signatures that could be remote-detected on exoplanets spans 137 cellular organisms and can be found here: http://biosignatures.astro.cornell.edu
It is hoped that the catalogue of organisms, which includes extremophiles from some of Earth’s harshest environments, could be useful in the search for extraterrestrial life, and that it could help to answer the question that has been with humanity since we first gazed at the stars and wondered, “Are we alone?” Image credit and original press release: https://cornell.box.com/exoearths
