Hubble captures rare triple moon transit of Jupiter
Above, is one of the beautiful images that Hubble took. Rarely do we get a chance to see three moons transit, or cross in front of, Jupiter simultaneously. In fact, a triple-transit like this will not happen again until December 2032. There are four Galilean satellites — named after the 17th century scientist Galileo Galilei who discovered them. They complete orbits around Jupiter ranging from two to seventeen days in duration. The moons can commonly be seen transiting the face of Jupiter and casting shadows onto its layers of cloud. However, seeing three of them transiting the face of Jupiter at the same time is rare, occurring only once or twice a decade.
The images were taken with Hubble’s Wide Field Camera 3 in visible light on 23 January 2015. Whilst Hubble captures these moons in great clarity they can also be seen with a small telescope or even a decent pair of binoculars.
Image credit: NASA, ESA, Hubble Heritage Team
There’s even an amazing video of the entire transit: