Europa’s Mysterious Glow

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Strange things could happen when radiation meets the icy surface of one of Jupiter’s moons. Europa is different from the others. According to new research, Europa might glow even on its night side, producing an ethereal glimmer without the help of the sun.

The glow arises from the special nature of Europa’s cosmic home. Jupiter’s magnetic field is the largest of any other planet in the solar system, and the radiation within its boundaries is many millions of times more intense than the radiation near Earth. The high-energy particles constantly bombard Europa, a world slightly smaller than our moon, with a wispy atmosphere. And when those particles strike the moon’s ice-covered surface, a quirk of chemistry could make it glow in the dark.

Hand has searched for signs of fluorescence on Europa using Hubble, the world’s top space telescope, but didn’t find anything. NASA scientists are now hoping that the glowing effect, if it indeed exists, is bright enough for the Clipper to capture it. The camera has yet to be built and tested, so scientists don’t know whether it will be sensitive enough to catch the gleam. But “it’s always exciting to discover something in the lab, and then have the opportunity to see if it translates into the real world,” Curt Niebur, a program scientist for the mission, told. “And we don’t get that opportunity a lot in planetary science.”