On October 14, SpaceX's Falcon Heavy rocket launched from the historic Launch Complex 39-A at Kennedy Space Center. Aboard was NASA's Europa Clipper spacecraft, the result of over a decade of work, aimed at exploring Europa, one of Jupiter's Galilean moons, which is crucial for astrobiology.
Jupiter, the largest planet in our Solar System, has approximately 95 officially recognized moons, four of which were discovered by Galileo Galilei in 1610: Io, Europa, Ganymede, and Callisto. Located about 618 million kilometers away—roughly four times the distance from Earth to the Sun—the mission will utilize gravitational assists from Mars in March 2025 and Earth in December 2026 to efficiently reach its destination.
This meticulously planned journey will last five and a half years. Once in an elliptical orbit around Jupiter in April 2030, Europa Clipper will spend a year fine-tuning its trajectory to approach Europa closely, conducting around 50 flybys at an altitude of just 25 kilometers at its closest point above the surface. Each pass will slightly alter the trajectory, enabling comprehensive scanning of nearly the entire moon.
Previous missions, including Pioneer 10 and 11, Voyager 1 and 2, Galileo, Juno, Cassini-Huygens, and New Horizons, have gathered substantial data indicating a vast ocean of liquid saltwater beneath Europa's icy crust, which is estimated to be between 3 to 30 kilometers thick.
Despite extreme temperatures, the internal water remains liquid, likely due to heat generated by gravitational flexing from Jupiter and its other moons. Europa's overall mass density suggests a primarily rocky interior composed of silicates, potentially with an iron and nickel core. Its surface is the smoothest of any known body in the Solar System, attributed to the movement of surface ice driven by subsurface water.
The Europa Clipper mission aims to understand the nature of the ice shell and the ocean beneath, along with the moon's composition and geology, to determine if there are locations beneath its frozen surface that could support life. The mission's success relies on the spacecraft's equipment, which includes cameras and spectrometers capable of producing high-resolution images and maps of both the surface and the thin atmosphere. Additional instruments include a magnetometer and a radar capable of penetrating ice, as well as devices to measure temperature and locate warmer areas in the ice and possibly recent water eruptions, along with an instrument to analyze small particles in the oxygen-rich atmosphere.
Europa Clipper is NASA's largest spacecraft built for an interplanetary mission to date. Its nine scientific instruments will closely examine the physical conditions of a body that holds promise as an environment potentially capable of supporting life. This mission complements the European Space Agency's JUICE mission, which will study Europa, Callisto, and Ganymede, as both seek to answer the question: are we alone? While JUICE will explore Europa, Clipper will search for signs of life in the ocean beneath Europa's icy surface, where liquid water, energy, and possibly essential chemical elements for life may abound.