Jupiter's moon Europa has long been considered one of the places most likely to host life outside of Earth, and new evidence significantly increases the chances that such life exists.
Beneath Europa's icy surface lies a deep ocean of water. NASA's Galileo mission has even indicated that the water has a salty quality similar to Earth's oceans. Now new evidence suggests that water from Europa's ocean is making its way to the surface. The study comes from Mike Brown of the California Institute of Technology in Pasadena and Kevin Hand of NASA's Jet Propulsion Laboratory.
"We now have evidence that Europa's ocean is not isolated - that the ocean and the surface talk to each other and exchange chemicals," Brown says. "That means that energy might be going into the ocean, which is important in terms of the possibilities for life there. "
The discovery also means that it may be possible to study Europa's water without digging through miles of ice.
"If you'd like to know what's in the ocean, you can just go to the surface and scrape some off," Brown adds.
It also suggests a chemical exchange between the surface and the ocean, implying that Europa's ocean may be chemically richer than previously believed.
Brown and Hand conducted their study by mapping water and ice distribution on Europa's surface. They did so using Hawaii's Keck II telescope. As a result they identified considerable amounts of magnesium sulfate. This is partly derived from magnesium chloride salt, which originates in Europa's ocean.
Europa is roughly the same size as our moon and has a diameter of about 1,940 miles. Its surface features few craters, meaning that it is a young moon whose surface is frequently being reformed by erosion, most likely from shifting ice floes.
Though the thought of alien life on Europa may not be something new, this new discovery makes the possibility even greater.
"If we've learned anything about life on Earth, it's that where there's liquid water, there's generally life," Hand says. "And of course our ocean is a nice salty ocean. Perhaps Europa's salty ocean is also a wonderful place for life."
