NASA Image Shows Off Volcanic Moon Io Casting A Shadow On Jupiter

NASA is always sharing cool images of something going on in the solar system, and this shot of Jupiter is no exception. The image shows a round solar eclipse on the surface of Jupiter cast by the shadow of Io as it orbits the giant planet. Io is an interesting satellite and was the first volcanically active object discovered outside of the Earth.

Scientists discovered that Io was volcanically active in 1979 when astronomers noted plumes of volcanic eruptions shooting into space. Io is studied as a window into Earth's distant past. Io also gives scientists a chance to study similar moons that might be found in distant solar systems.

It's interesting to see the small shadow of Io cast on the massive surface of Jupiter. The view is similar to what we would see from a distance during a solar eclipse on Earth. A solar eclipse is when the moon blocks the sun as seen from the planet.

Io shadow advancing across Jupiter. @NASAJuno Perijove 22 pic.twitter.com/XceGxSRHCN

— Brian Swift (@b_swift) September 17, 2019

The image was captured by NASA's Juno spacecraft on September 12 as the spacecraft was making its 22nd close flyby of the massive gas giant. During the flyby that snapped the picture, Juno was as close as about 5,000 miles to the top of the clouds covering Jupiter.

The spacecraft was traveling at 46,000 mph as it made its pass. We don't have much in the way of detail on the image, such as what sort of processing was made, if any, to the picture. Kevin Gill offered it on September 16. Jupiter is a beautiful planet with all the colors swirling around its surface constantly.