text: NASAs Europa Clipper probe is designed as a flyby mission to Jupiters smallest Galilean moon, Europa. Set to launch in 2024, this probe will investigate the potential for habitability on Europa. Europa is one of the best candidates for biosignature discovery in the Solar System because of the scientific consensus that it retains a subsurface ocean, with two to three times the volume of water on Earth. Evidence for this subsurface ocean includes:
  *Voyager 1 (1979): The first close-up photos of Europa are taken. Scientists propose that a subsurface ocean could cause the tectonic-like marks on the surface.
  *Galileo (1997): The magnetometer aboard this probe detected a subtle change in the magnetic field near Europa. This was later interpreted as a disruption in the expected magnetic field due to the current induction in a conducting layer on Europa. The composition of this conducting layer is consistent with a salty subsurface ocean.
  *Hubble Space Telescope (2012): An image was taken of Europa which showed evidence for a plume of water vapor coming off the surface.
  The Europa Clipper probe will carry instruments to help confirm the existence and composition of a subsurface ocean and thick icy layer. In addition, it will map the surface to study features that may point to tectonic activity due to a subsurface ocean.