
Behold the volcano-blanketed moon, Io.
After swooping by Jupiter's tortured moon on Feb. 3, NASA's Juno spacecraft beamed back some of the closest-ever images of this unique world. The agency's deep space probe came within just 930 miles (1,500 kilometers) of Io, following a similar pass just over a month ago. Planetary scientists hope these much-anticipated flybys will answer fundamental questions


