We’re One Step Closer to Understanding a Moon That Could Be Home to Alien Life

This week we are one step closer to understanding a world in our solar system that I believe has the best chance of supporting life beyond our own planet. NASA has just announced details about what instruments a space probe to Jupiter’s moon Europa will carry when it makes multiple flybys in the next decade.

I couldn’t be more excited to be the project scientist of this mission. I first learned of Europa as a kid who made planets out of tennis balls covered in construction paper and masking tape and hung them from my bedroom ceiling on Long Island. In 1979, the twin Voyager 1 and Voyager 2 spacecraft flew past Jupiter and its moons. Though not the largest moon of Jupiter, Europa was the most enigmatic: Voyager’s pictures showed a maze of dark lines marking the bright icy surface, like a cracked eggshell.

From Zócalo Public Square

Seeing the first Voyager 2 photos of Europa inspired the famous Carl Sagan to wonder whether the dark bands were mountain-like ridges or valley-like troughs. What do they say about the history of this world? I was fortunate to take Sagan’s seminar course at Cornell University in 1985 and was fascinated by the possibility of a watery ocean within Jupiter’s moon Europa. It was uncertain whether such an ocean would have frozen solid over time or could persist today.

To learn more, NASA sent the Galileo spacecraft past Europa a dozen times while orbiting Jupiter between 1996 and 2002. Galileo images showed Europa’s surface to be crisscrossed by both mountain-like ridges and valley-like troughs. The patterns of the ridges and cracks suggest an ocean below that permits the ice shell to flex and break. Giant bulls-eye-like scars tell of large comets that collided with —> Read More