Scientists think six icy moons in our solar system may currently host oceans of liquid water beneath their outer surfaces. Arranged around Earth are images from NASA spacecraft of, clockwise from the top, Saturn's moon Enceladus, Jupiter's moons Callisto and Ganymede, Neptune's moon Triton, Saturn's moon Titan, and Jupiter's moon Europa, the target of NASA's Europa Clipper mission. The worlds here are shown to scale.

The images of the Saturnian moons were taken by NASA's Cassini mission. The images of the Jovian moons were taken by NASA's Galileo mission. The image of Triton was taken by NASA's Voyager 2 mission. The image of Earth was stitched together using months of satellite-based observations, mostly using data from the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Terra satellite. More information about the Earth image can be found here.