Like Io, Europa orbits near Jupiter and has sizable moons orbiting past it. The ensuing gravitational results additionally soften Europa’s subsurface layer, however as a result of this moon consists largely of water ice, its melted layer is a large ocean of liquid water.
Information collected by NASA’s Voyager and Galileo missions recommend that beneath about 30 kilometers (19 miles) of ice, Europa could also be holding an ocean 70-100 kilometers (43-62 miles) deep. Regardless that Europa is smaller than Earth’s moon, its oceans are thought to comprise twice as a lot liquid water as all of Earth’s oceans and lakes mixed.
This might make Europa an particularly promising place to search for life, as a result of liquid water is essential for all times as we all know it. Europa’s subsurface oceans might produce other life-friendly qualities as nicely, together with safety from radiation. Europa’s oceans additionally seem like salty, which could imply that they might be in direct contact with a rocky seafloor under. Earth’s oceans get most of their salt from hydrothermal vents within the seafloor, and these vents are among the many most definitely locations the place life first emerged on Earth. The essential elements for making life appear to be water, natural compounds, and an power supply, and the warmth popping out of hydrothermal vents might have offered the power wanted to show non-living elements into life.
For all these causes, Europa is a vital goal within the seek for life past Earth. To raised perceive this world and its doable habitability, two missions are going to review Europa within the coming years: the European House Company’s Jupiter Icy Moons Explorer (Juice), which launched in April 2023, and NASA’s Europa Clipper, which is about to launch in 2024.
Ganymede
Persevering with our trajectory out from Jupiter, the following Galilean moon we come to is Ganymede. It’s the largest moon within the Photo voltaic System, even greater than the planet Mercury. It’s additionally the one moon within the Photo voltaic System that has its personal magnetic discipline.
