Now back to those first NASA probes. They observed long lines and dark spots on the moon Europa. Typically moons have cratered surfaces, but these images 12tipped scientists off that there might be an ocean beneath the Europa's icy exterior. In 1996, that theory was confirmed when the Galileo spacecraft reached Europa.
It was the first ocean discovered on another planet. Then in 2012 and 2016, the Hubble Space Telescope showed 13water plumes 14eruptingfrom the warmest parts of Europa. Scientists don't know much about the plumes, but if Europa has water and elements like carbon and hydrogen, it could mean that 15microbial life once formed there, or even still exists.
