Life on Mars and Elsewhere in the Solar System: NASA's Search

Perseverance is collecting and caching rock and surface samples at Jezero Crater for eventual return to Earth, and NASA is preparing missions to study icy moons such as Europa, Enceladus and Titan.

NASA is continuing a focused search for signs of past life in the solar system, with the Perseverance rover collecting samples at Jezero Crater. Earlier missions and studies produced intriguing but inconclusive results that shaped current methods. Rovers and orbiters have documented environments on ancient Mars that were once wet and potentially habitable. The agency also plans to study icy moons that may hide oceans beneath their surfaces. Key developments: - The Perseverance rover is exploring Jezero Crater and caching rock and surface samples in metal tubes for eventual return to Earth. - Viking landers (1976) and the 1996 analysis of the Allan Hills meteorite produced early, inconclusive life-detection findings that influenced later approaches. - Spirit, Opportunity and Curiosity provided geological evidence that early Mars had flowing water, organic molecules and habitable environments. - NASA's Cassini mission detected plumes of salty water and organic molecules on Enceladus, suggesting a subsurface ocean as a possible habitable environment. - Missions in development include Europa Clipper, described as being assembled for a possible launch in October 2024, and Dragonfly, planned for the mid-2030s to explore Titan. Summary: NASA's current strategy favors comprehensive, context-rich investigations on Mars that pair in situ measurements with samples that can be analyzed on Earth. Lessons from Viking and the Allan Hills meteorite led to more careful interpretation and the emphasis on environmental context. Parallel efforts continue to study icy moons with planned missions that could sample or analyze plume and surface material in the years ahead.