Is there life elsewhere in our solar system?

A grand odyssey of exploration is about to begin. Humankind’s next bold mission to the outer solar system. ESA’s Jupiter Icy Moons Explorer (Juice), is poised to explore giant planet Jupiter and its largest moons. After years of preparations, Juice will be launched into space on April 13 from Europe’s Spaceport in French Guiana. The mission, in which TU Delft plays a leading role in the experiment PRIDE, is diving into orbit of a moon other than Earth’s for the first time. Something the Americans, Japanese and Chinese have never succeeded in doing before.

Juice will be heading to Jupiter soon. A childhood’s dream?

Dirkx: “When I was 12 years old, I saw a news report on TV about the launch of the Cassini satellite to Saturn and its moons. I remember very clearly thinking: how great it would be to participate in something like that. Now, 25 years later, that’s exactly what I’m doing.”

Vermeersen: “I consciously experienced the Apollo landings, and remember well that in the 1970s the general scientific opinion was that there was no extraterrestrial life in our solar system. After all, the initial findings for life on Mars were negative, and further into the solar system you got outside the habitable zone, people thought. How different is the situation now. One of Juice’s most important and appealing reasons, is the possibility of existing extraterrestrial in our own solar system.”

So, are we going to find that on Jupiter?

Vermeersen: “Juice is probably not going to answer that directly, but hopefully indirectly. Jupiter’s four major moons are worlds unto themselves. The innermost moon, called Io, is the most volcanically active celestial body in the solar system. The other three major moons, Europa, Ganymede and Callisto, are completely covered in water ice. These ice moons are very interesting because they almost certainly have layers of water inside. And of ice moon Europa we know, from observations of the NASA Galileo mission, that there must even be a saltwater ocean. And not just any ocean This one contains more ocean water than all the oceans on Earth combined. And consider, that the bottom of the Europa ocean must consist of solid, rocky material, with probably active volcanism, and that this Europa ocean has probably existed for billions of years. Then all conditions are present for the emergence and evolution of life. Whether the suitable habitat is actually there, and how large and deep below the ice these oceans are in Jupiter’s icy moons, is one of Juice’s main goals.”

What else do we want to discover?

Vermeersen: “We see tectonic activity on the surface of Europa and Ganymede. Ice sheets moving past each other with peculiar crack formations, which indicate that strong ice moon quakes are occurring. Furthermore, it is unclear why Europa is so active, while Callisto appears to be dead as a doornail. The strong tidal movements of Jupiter, the most massive planet in our solar system, seem to be the cause of this activity. But how all this is related, we do not know. We therefore want to better understand how the overall Jupiter system works.”

JUICE exploring the Jupiter system and its icy moons. Credit: ESA