There is currently no good evidence of life or fossil life on other worlds in the solar system, let alone on exoplanets in other solar systems. That may change as we continue exploring other worlds in the solar system. Even if no living organisms are found elsewhere, our investigations will shed light on the processes of prebiotic chemistry and primordial geochemistry.²⁵The planet Mars and the moons Europa, Enceladus and Titan all have or had environmental conditions similar to parts of Earth. Future missions such as ExoMars and Europa Clipper — launched late 2024 but not due to arrive at Europa until 2030 — will provide information about processes that are likely to have taken place on the young Earth. A key opportunity for the coming decades will arise with sample-return missions that can bring high-quality samples back to Earth for detailed study.

Future Horizons:

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5-yearhorizon

Mars gives clues to Earth-like prebiotic chemistry

Data from the Perseverance rover on Mars indicates Earth-like prebiotic chemistry billions of years ago.

10-yearhorizon

Solvents for life are better understood

We have good evidence on whether water is the only possible solvent for life. The James Webb Space Telescope has given useful information about the conditions in which terrestrial planets formed and the abundance of specific organics in these conditions.

25-yearhorizon

Mars sample return planned

Examples of life or fossil life on other worlds are found, helping to expand or clarify our definition of life. A plan for a high-quality sample-return mission to Mars is drawn up.

Discovering life beyond the solar system remains a possibility, if a remote one. It is theoretically possible to find indirect evidence of life on an exoplanet, for example by detecting the presence of oxygen in the atmosphere through spectroscopic analysis. However, there are issues with interpreting such detections: on Earth, oxygen is produced by only living organisms, but it is difficult (if not impossible) to rule out abiotic processes being the cause on an exoplanet.²⁶ This problem has already bedevilled researchers who detected methane on Mars and phosphine on Venus, and will be far worse when dealing with extremely distant worlds.²⁷

Exobiology - Anticipation Scores

The Anticipation Potential of a research field is determined by the capacity for impactful action in the present, considering possible future transformative breakthroughs in a field over a 25-year outlook. A field with a high Anticipation Potential, therefore, combines the potential range of future transformative possibilities engendered by a research area with a wide field of opportunities for action in the present. We asked researchers in the field to anticipate:

The uncertainty related to future science breakthroughs in the field
The transformative effect anticipated breakthroughs may have on research and society
The scope for action in the present in relation to anticipated breakthroughs.

This chart represents a summary of their responses to each of these elements, which when combined, provide the Anticipation Potential for the topic. See methodology for more information.