Jupiter moon Europa could have oceans of life

18 May 2016

NASA scientists think the icy, salty oceans on Europa have the potential to be just like Earth’s bodies of water, with hydrogen and oxidants all around.

NASA is prioritising a mission to Mars. We all know this. We’re all in favour of this. It’s the next landmark, crewed stage in space exploration.

However, beyond the Red Planet, there are a few places that might be worth a closer look. Two of the places in particular orbit Jupiter, with Europa and Io the home of hugely important discoveries in recent years.

Heat on Io, water on Europa

The latter is the most volcanically active body in the solar system, due to the fact that Jupiter’s massive gravitational pull is continually putting pressure on Io’s core.

The former, though, has oceans. NASA estimates it has subsurface bodies of water up to 25km deep, over double the volume of Earth’s entire oceanic network.

Locked below a surface of ice, scientists believe it’s salty enough to be fluid and that, over the billions of years since it was formed, cracks in the seabed have released wave after wave of nutrients, which could help form life.

Notably, hydrogen and oxygen, a new paper claims, is produced at the same rate as on Earth – the latter found at 10 times the rate of the former.

Europa Earth seafloor

A submersible rests on the seafloor above a region of active serpentinisation near the Lost City hydrothermal vent field in the mid-Atlantic Ocean. Carbonate minerals visible in the foreground are created by this geochemical process, which can produce hydrogen as a byproduct, via Kevin Peter Hand

More studying to do

“We’re studying an alien ocean using methods developed to understand the movement of energy and nutrients in Earth’s own systems,” said Steve Vance, a planetary scientist at JPL and lead author of the study

“The cycling of oxygen and hydrogen in Europa’s ocean will be a major driver for Europa’s ocean chemistry and any life there, just as it is on Earth.”

Vance and his colleagues don’t know much about carbon, nitrogen, phosphorus and sulfur in Europa’s oceans, but hydrogen is thought to be released as the water interacts with cracks formed in the rocky frame of the water.

From above, oxidants are spread from radiation off Jupiter. If these are absorbed into the water below the surface, they could react with hydrogen to form life.

“The oxidants from the ice are like the positive terminal of a battery, and the chemicals from the seafloor, called reductants, are like the negative terminal,” said Kevin Hand, a planetary scientist at JPL who co-authored the study.

“Whether or not life and biological processes complete the circuit is part of what motivates our exploration of Europa.”

Europa image via Shutterstock

Gordon Hunt was a journalist with Silicon Republic