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NASA is getting ready to launch a spacecraft to Europa, an icy moon of Jupiter. It's considered to be one of the best places in the solar system to look for life. NPR's Nell Greenfieldboyce reports.
NELL GREENFIELDBOYCE, BYLINE: Europa was discovered in 1610 by the famous astronomer Galileo. Hundreds of years later, a NASA spacecraft named after him flew by this moon and revealed that beneath its icy crust, it seemed to have an ocean of liquid water.
BONNIE BURATTI: We're pretty certain that the ingredients for life exist on Europa, but we have to go there to find out.
GREENFIELDBOYCE: Bonnie Buratti is the deputy project scientist for this NASA mission, called Europa Clipper. She says the moon's surface is crisscrossed with mysterious dark streaks and a so-called chaos terrain of jumbled ridges and cracks.
BURATTI: That may give evidence for interactions with the global ocean down below.
GREENFIELDBOYCE: Way down below. The moon's crust of ice could be over 10 miles thick. The ocean below that could be more than 60 miles deep. If there's any life on Europa, it's likely hidden beneath all of that. That's why Buratti and her colleagues don't expect to actually find life.
BURATTI: We're looking for chemicals on the surface - organic chemicals that are the precursors to life.
GREENFIELDBOYCE: During a press briefing, NASA officials said everything is on track to launch Europa Clipper on Oct. 10. The trip to Jupiter is about 1.8 billion miles, a voyage that will take more than five years. Project manager Jordan Evans says once it gets there, the spacecraft will fly by Europa dozens of times.
JORDAN EVANS: And to be clear, we're not landing on Europa. We do get as close as 25 kilometers above the surface. That's about 16 miles.
GREENFIELDBOYCE: The radiation there is intense. He says during each flyby...
EVANS: The surface of the spacecraft is exposed to the equivalent of a few million chest X-rays. And yet the Europa Clipper instruments have to be sensitive enough to gather the critical information that scientists need to learn about the moon.
GREENFIELDBOYCE: The spacecraft also needs to cope with the lack of sunlight so far out. Its twin solar panels are each over 45 feet long and nearly 15 feet high, making this the biggest interplanetary spacecraft that NASA has ever built. Once its mission is over, it will crash-land on another Jupiter moon, Ganymede.
Nell Greenfieldboyce, NPR News.
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