Europa might be most habitable after Earth

Nicole Sanseverino

Europa, one of Jupiter’s at least 63 moons, is about 500 million miles away from earth, but comes closer to resembling our planet and providing potential for life than anything else in the solar system, researchers said.

UT researchers discovered what they said appears to be a body of liquid water the volume of the North American Great Lakes locked inside the icy shell of Europa.

The “lake” holds potential as a habitat for life, and there may be many more such lakes throughout the shallower regions of Europa’s shell, said lead author Britney Scmhidt, postdoctoral fellow at the Institute for Geophysics, in the article.

The idea of liquid water beneath Europa’s surface is nothing new, said Robert Pappalardo, senior research scientist for NASA.

“For a while now, since the first Galileo pictures in the mid-90s, there has been mounting evidence that there is a liquid water ocean under the icy shell of Europa,” Pappalardo said. “Although how far down has been a topic of debate.”

Researchers focused on images from Galileo, the first satellite to orbit Jupiter, which showed two roughly circular, bumpy features on Europa’s surface called “chaos terrains.”

The chaos terrains look like an ice-covered puddle all broken up and full of little ice pieces, said Don Blankenship, co-author and senior research scientist at the Institute for Geophysics.
Pappalardo said according to Blankenship and Schmidt’s model, these chaos terrains are formed by blobs of warm ice, which are heated as Europa orbits Jupiter.

“[Europa] is squeezed,” Pappalardo said. “It flexes in and out, and that creates heat like bending a paper clip back and forth.”

The squeezed blobs of warm ice, like a lava lamp, float to the surface, pushing the surface up, Pappalardo said.

As the ice melts, the water takes up less room causing the surface to cave in, forming fractures near the surface.

The lake of water, which exists beneath the sinking ice shelf, may provide a mechanism for transferring nutrients and energy between the surface and the vast ocean which is thought to exist beneath, according to their research.

Interaction between the surface and the ocean beneath could make Europa and its ocean more habitable, Schmidt said.

Pappalardo said the model is a step forward in understanding the potentially habitable moon, but that further exploration is necessary. Pappalardo and his team of scientists are planning a six-year space mission, which he estimates will start in 2020.

The federal government cut nearly $240 million to NASA’s 2011 budget, consequently cutting funds to many of NASA’s programs. However, Pappalardo said Washington continues to see the value in the space mission and have called Europa a top-priority.

Pappalardo said sending a satellite to Europa would cost around $1.5 to $2 billion, “a large amount,” but a worthwhile one, he said.

“It comes out to a dollar a person, kind of a candy bar or a can of soda per person per year to fund a planetary mission like this,” Pappalardo said. “That is not too bad to understand whether there are habitable regions elsewhere in the solar system.”