Callisto – one of Jupiter’s moons – was discovered in 1610 by Galileo Galilei and is the third-largest moon in the Solar System and the second largest in the Jovian system. Submitted by Mike Salway, the following animation shows Callisto transiting across the face of Jupiter:

Accompanying the eighteen frame animation – covering over 3 hours of rotation – Mike Salway notes:

Finally got around to processing all of the data from last Saturday morning, 30th May UT. Seeing was variable (mostly just above average) but for about 30 minutes it really steadied and I was able to capture probably my best image for the year so far.

Callisto is shown transiting across the face of Jupiter – it’s very very dark!

Captured with 12″ newt, DMK 21AU04. Processed in Registax v5 (beta).

Awesome work Mike! Keep it up!