Jupiter with the Great Red Spot. The red storm is actually shrinking each year. The black dot you see is the shadow of it's closest moon, IO, transiting across the face of it. Jupiter's day is only 10 hours long, so over the course of the night things change very quickly. By the time I packed it in at 3:00 am, the red spot had already rotated to the night side of the planet! Jupiter is at opposition with us and the sun on the 14th.

Canon 6D
C9.25

1700 frames stacked in autostakkert! and processed in Registax.