NASA Finds New Evidence of Habitability on Jupiter’s Moon Europa

As scientists continually search space for signs of life, Europa, Jupiter's moon, is one of the top candidates. New modeling shows that the moon's oceans on the subsurface can support life.

NASA has calculated how either heat from tidal forces or radioactive decay has turned ice into liquid water even though surface temperatures reach up to -225 degrees Fahrenheit. Enceladus, one of Saturn's moons, might also have subsurface liquid oceans beneath the thick surface ice. Scientists have detected water vapor spurting out of the surface of both moons.

This spark hopes that someday, these moons may be habitable with striving hydrothermal vent ecosystems similar to Earth's. Humans will be able to harness energy from the depths of the moon's ocean, where volcanic vents generate heat into the surrounding waters. This chemical energy, called chemosynthesis, can be used to produce food in a similar way that solar energy is being used today.

Preparing for Europa Clipper Mission

By 2024, NASA is planning to launch a mission to Jupiter's moon, the Europa Clipper. For now, they continue to make models of where and how to find these signs of life on the moon. Planetary scientists Mohit Melwani Daswani and Steven Vance take the lead on this new study.

Their main focus is figuring out the original source of the moon's water. Their current data suggests that perhaps water-bearing minerals had been heated and broken down by radioactive decay over time. Another theory is that it's a result of tidal force as it orbited Jupiter or a combination of both theories.

The team created a model of the physical properties and composition of Europa's core, silicate layer, and ocean. Daswani explained, 'We find that different minerals lose water and volatiles at different depths and temperatures. We added up these volatiles that are estimated to have been lost from the interior, and found that they are consistent with the current ocean's predicted mass, meaning that they are probably present in the ocean.'

How the Ocean Formed

NASA's Hubble Space Telescope has been able to detect a salt-like substance on the moon's surface, and plenty of it, additional proof of a salty ocean beneath the surface. Their simulation also shows how the ocean may have transformed over time. It most likely had mildly acidic origins, similar to Earth, containing carbon dioxide, sulfate, and calcium.

'Indeed it was thought that this ocean could still be rather sulphuric, but our simulations, coupled with data from the Hubble Space Telescope, showing chloride on Europa's surface, suggest that the water most likely became chloride rich,' Daswani said. This means that the ocean composition is quite similar to Earth's oceans, making the waters suitable for life to be built around it.

Next, the NASA team will be assessing if other conditions for habitability are present on Europa. The surface has indicated that it is geologically active due to venting plumes of vapor. This is a result of tidal force with Jupiter and the planet's other moons Io and Ganymede, which may be responsible for the liquid ocean.

Daswani shared 'Our models lead us to think that the oceans in other moons, such as Europa's neighbor Ganymede, and Saturn's moon Titan, may also have formed by similar processes. We still need to understand several points though, such as how fluids migrate through Europa's rocky interior.'