Enlarge / This processed image of Io was captured by Juno’s JunoCam instrument July 30. (credit: NASA/JPL-Caltech/SwRI/MSSS/Thomas Thomopoulos)

The last time a spacecraft got this close to Jupiter’s moon Io was more than 20 years ago, a blink of an eye on a typical geological timescale. Most planetary bodies in our Solar System wouldn’t exhibit so much change in a couple of decades.

But Io is different, with volcanic eruptions regularly remaking parts of the moon’s crust. That means there’s a good chance something on Io has changed since NASA’s Galileo orbiter last encountered it in 2002.

NASA’s robotic Juno spacecraft is delivering the fresh data on Io with a series of flybys, each getting closer to Jupiter’s volcanic moon until a pair of close-up encounters at a range of less than 1,000 miles (about 1,500 kilometers) in December and February.

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