[dayglored]

Question for you SunkenCiv -- Since from Jupiter's orbit the Sun is much farther away and thus much smaller (angle in the sky), would that mean that the shadows cast on the surface of the planet by the moons would be more sharp-edged than the shadow our Moon casts on the Earth during a solar eclipse? In particular, is there any significant amount of penumbra?

I don't think I've ever seen that discussed... just wondering if you know or have an opinion. Thanks!

[dr_lew]

Yes the shadows would be more sharp edged, and very noticeably so. You can get this effect here on earth if you’re in a glass lined hallway above a parking lot to the south ( in the northern hemisphere, ) and you get a bright windshield reflection from a car. The convex windshield will produce an angularly small sun, and you may even see edge diffraction if you look at a shadow closely.

“The amount of penumbra” is subject to interpretation. In general, an object which “just covers” the sun, as the moon does from earth, will have a similar effect in eclipse from a given viewing point, except that the eclipsed disc will be smaller in appearance.

... Good question! ... and excuse me for butting in.