NASA spacecraft beams back tantalizing images of volcanic world Io

There's a moon teeming with lava-spewing volcanoes in our solar system, and a NASA spacecraft is getting closer to this intense world.

The pioneering Juno spacecraft, which arrived at Jupiter in 2016 and is now swooping by the planet's intriguing moons, recently snapped images of the Jovian moon Io from some 32,044 miles...