For as long as humans have gazed into the night sky, we have wondered about life beyond the Earth. Scientists now know that several places in our solar system might have conditions suitable for life. One of these is Jupiter’s moon Europa, a fascinating world with a salty, subsurface ocean of liquid water—possibly twice as much as in all of Earth’s oceans combined. However, scientists had not confirmed if Europa’s ocean contained biologically essential chemicals, particularly carbon, the universal building block for life as we know it. Now, using the James Webb Space Telescope, astronomers have found carbon on Europa’s surface, which likely originated in this ocean. The discovery signals a potentially habitable environment in the ocean of Europa.