Some 25 or so years ago, during Jupiter opposition I observed one of its moons partially occult its own shadow, making it into a crescent shape. I'm not sure which moon it was, but it was easily seen with a C11 stopped down to 5 inches. This type of event will only occur within a day or two of opposition.
On Aug 19 this year, from about 10PM EDT to midnight, Io will transit and occult approx half its shadow. The non-occulted part of the shadow should be visible as a crescent shape.
I have attached a pdf of the view as simulated using Guide 9.1.
Clear skies, please!
Io transit and shadow occultation Aug 19 2021.pdf 302.79KB 44 downloads