From ocean moons in our solar system to Earth-sized exoplanets around distant stars — explore every serious candidate where life might exist, and why science thinks so.
Moon of Saturn · 1.2 billion km (average)
Enceladus shoots jets of ocean water directly into space, allowing spacecraft to sample its subsurface sea without landing. Those samples contain hydrogen, organic molecules, and silica nanoparticles — fingerprints of active hydrothermal vents on the ocean floor.
Moon of Jupiter · 628 million km (average)
Europa conceals a global liquid water ocean twice the volume of all Earth's oceans beneath a cracked ice shell, with evidence of hydrothermal activity — making it one of the most promising places to search for life in the solar system.
Exoplanet · 39.5 light-years
One of seven rocky planets orbiting the ultra-cool red dwarf TRAPPIST-1, planet e sits squarely in the habitable zone and is considered the most likely of the system's worlds to support liquid water — it receives almost exactly the same amount of energy from its star as Earth does from the Sun.
Each candidate has its own page covering the science, evidence, challenges, and active missions.
Try the Drake Equation, Habitable Zone calculator, and Travel Time estimator with adjustable sliders.
Every page covers the real missions — Europa Clipper, Dragonfly, JWST, Perseverance — actively searching for answers.