NASA has awarded nearly USD seven million to an effort aimed at developing a new kind of extraterrestrial life detection system that could be used on Mars, scientists say. The interdisciplinary project, called the Laboratory for Agnostic Biosignatures, will develop a new class of life detection approaches for use on planetary missions -- from the subsurface of the Mars to the farthest reaches of our solar system.
"Time and again, we have been bowled over by the indescribable foreignness of other worlds," said Sarah Stewart Johnson from Georgetown University in the US. "Yet the search for extraterrestrial life often defaults to assumptions that arise from experiences with life detection on Earth," said Johnson, the project's principal investigator.
NASA's Astrobiology Program awarded the USD seven million grant to the effort explicitly aimed at throwing out the assumption that life out in space will be like life here at home. "Detecting life in an agnostic fashion means not using characteristics particular to Earth life," said deputy principal investigator Heather Graham of NASA Goddard Space Flight Center.
For example, the team will consider states of disequilibrium with the surrounding environment, such as evidence of conspicuous chemical complexity or unexpected accumulations of chemical elements, Graham said. They will also look for patterns of energy transfer in the hope that such aberrations could tip off the researchers to the existence of life. The key for the project is to identify indicators that are not biased towards the specific type of biochemistry found on Earth.
The life detection methods must also be suitable for eventual implementation on flight missions. "Our goal is to go beyond what we currently understand and devise ways to find forms of life we can scarcely imagine," Johnson said.
The project will also explore ways to think about the discovery of life in terms of probabilities and thresholds, as opposed to seeking a simple "yes" or "no" as to whether life has been discovered. "When you are looking for extraterrestrial life, results may be messier than just 'yes we found life' or 'no we didn't,'" Johnson said.
"To do that, we'll need to think less about whether life fits our preconceptions of what life is, and more about how to quantify the difference between what we see and what we might expect from an abiotic environment," she said.
Researchers said the project will support computational efforts to develop probabilistic and theoretical models, some of which will depend on advanced algorithmic and machine learning techniques. It will also oversee the analysis of a wide array of organic and inorganic substrates, including abiotic extracts from meteorites, which will be used to develop and refine these tools and algorithms, they said.
