The Opportunities From Machine Learning Applications in Astrobiology – NASA-DARES 2025

Caleb Scharf, NASA Ames Research Center

The search for life represents a unique data challenge within modern science. Machine learning, as it is now and may be in the future, offers many new opportunities for addressing this challenge. Astrobiology should systematically investigate and evaluate those opportunities or risk diminished scientific returns.

At its core the search for life is a search for life’s imprints in the world, reflected in the features in data; meaning the measurable properties, variables or attributes in data associated with those imprints. To try to determine whether life exists, or has existed, elsewhere in the universe, evidence of the nature of those features is accumulated through measurement and experimentation. But the necessary measurements or experiments needed to verify and characterize life vary according to circumstances.

One extreme example would be if extant extraterrestrial organisms were acquired in sufficient abundance so that a definitive claim could be made for the presence of life that is directly and uniquely assignable to its native surroundings. At the other extreme is the accumulation of many correlated pieces of evidence – both contextual and direct – that individually do not fully confirm or reject biogenicity but together lead to a probabilistic estimate of the existence of life (e.g., [1-3]). Such evidence might require the mapping and monitoring an entire planetary object (or even an entire planetary system) across heterogeneous spatial conditions and varied temporal scales.

In any given case, including these extremes, proof of discovery will be less significant without the construction of a plausible history and characterization of the lifestyle of any living systems. For example, the discovery of an abundant, high complexity organic molecular species in an environment (with complexity gauged by an approach such as assembly theory [4]) would be very strong evidence of biogenicity. But if there were no robust hypothesis for the origin of such molecules (e.g., if there was no match to any known biochemical function or byproduct, or if these molecules existed in surprising conditions), it would be hard to see this as full confirmation of biogenicity – although it would clearly prompt much further investigation.

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Astrobiology