On October 14, 2024, NASA’s Europa Clipper launched from Kennedy Space Center on a Falcon Heavy rocket, beginning a journey to one of the most scientifically interesting objects in the solar system. The spacecraft will reach Jupiter in 2030 and spend four years performing 49 close flybys of Europa, Jupiter’s fourth-largest moon.
The goal is to determine whether Europa’s subsurface ocean could support life.
Why Europa
Jupiter has 95 known moons. Europa is special because of what lies beneath its icy crust: a liquid water ocean estimated to contain twice as much water as all of Earth’s oceans combined, kept liquid by tidal heating from Jupiter’s immense gravitational field.
Water, by itself, is not enough for life. But Europa’s ocean is thought to be in contact with a rocky seafloor, which means the same kind of hydrothermal chemistry that sustains life in Earth’s deep ocean vents could potentially be occurring there. Tidal heating drives fracturing in the ice above, which may allow material from the surface to cycle down into the ocean and vice versa, providing a pathway for chemical gradients that life could exploit.
The conditions are not guaranteed. The radiation environment at Europa, driven by Jupiter’s magnetic field, is intense enough to sterilize the surface. But the ocean below the ice is shielded. If anything lives there, it would have to live in the deep water, not the surface.
What the spacecraft will do
Europa Clipper carries nine science instruments, including ice-penetrating radar, a thermal emission imager to find regions of warmer ice, a mass spectrometer to analyze the composition of material ejected from the surface, and cameras capable of resolving features smaller than a meter.
The mission will not land on Europa, and it will not drill through the ice. It is a reconnaissance mission, designed to characterize the moon’s habitability, identify the most promising landing sites, and provide the foundation for a future lander mission.
The planned 49 flybys will collectively cover most of Europa’s surface at close range, building a picture of what the ice is made of, where the ocean is closest to the surface, and whether any plumes are actively venting material from the ocean into space, as some Hubble observations have suggested.
The arrival at Jupiter is six years away. The data collection will take another four years after that. The results, whatever they are, will be among the most significant in the history of planetary science.