The Jupiter Icy Moons Explorer mission, JUICE (Artist impression).
The Jupiter Icy Moons Explorer mission, JUICE (Artist impression). (Courtesy Photo by ESA/AOES)

LA CANADA FLINTRIDGE - NASA is sending instruments to three of Jupiter's moons in 2030, part of a European mission to explore potentially habitable, water-filled worlds that many astronomers consider the likeliest location in the solar system for microbial life.

Jet Propulsion Laboratory scientists will direct the U.S. portion of the Jupiter Icy Moon Explorer mission, or JUICE, contributing a radar instrument similar to the one used to probe Mars' polar ice caps.

The European Space Agency is leading the entire mission, while the radar exploration is led by the University of Trento in Italy.

"This spacecraft is going to have a really capable set of instruments, and we believe we can do some great science," said Jeffrey Plaut, JPL's lead investigator on the JUICE mission.

Set to launch in 2022 and arrive eight years later, JUICE will fly by two of Jupiter's icy moons, Europa and Callisto, before settling into orbit around a third moon, Ganymede.

All three moons have vast underground oceans below their icy surfaces.

Using the radar sounder, scientists expect to get a detailed picture of what the terrain looks like up to 5 miles underground.

The overall mission is to map the moons' surface, structure and atmosphere, potentially paving the way for future manned missions.

Conditions on Europa are considered the most favorable for life, though JUICE will only fly by that moon twice.

That could be enough to settle scientific debate about how deep Europa's underground ocean is, Plaut said.


Some say it starts at 10 kilometers underground, while others believe it could be 30 kilometers below the surface.

The radar technology is also similar to aerial research above Antarctica, where scientists recently announced the discovery of bacterial life.

"That kind of evidence gets us thinking there could be environments for life on these moons," Plaut said. "The ocean of Europa has a lot of the ingredients that we think life needs, but we don't know if it's a place where life evolved."

JUICE will carry 11 instruments, built by teams from the U.S., Japan and 15 European countries.

NASA is also contributing a particle environment instrument to measure the effects of Jupiter's hot magnetosphere and an ultraviolet spectrometer to study the atmospheres of the three moons and how they interact with Jupiter.

The Southwest Research Institute in Arizona is developing the ultraviolet spectrometer.

The JUICE spacecraft will also work in coordination with NASA's Juno mission, which is currently traveling to Jupiter and will orbit around the planet's polar caps beginning in 2016.