Last night there was an interesting observation on Jupiter last night 1730 to 1900. Callisto grazed the limb of the planet while orbiting and better yet it grazed the Jovian north pole. Now all the moons have to orbit in the equatorial plane so how can a moon have a grazing pass over the pole? Well it's an optical trick caused by the tilt of Jupiter in relation to our solar system's planed of the ecliptic. Callisto of course was in the usual orbit but because of the tilt it looked like it passed over the pole. I have often seen the moons go in back or in front of the planet but never have I seen one appear to skim the limb very low and not touch it, much less over a pole of the planet. Close observation of Jupiter reveals this axial tilt right now. Assuming that the distance from belt to respective pole is more or less equal (see drawing), the distance should be the same optically. Last night, the distance from the Northern Equatorial Belt (NEB) to the pole was quite a bit greater than the distance of the Southern Equatorial Belt to the south pole due to planet tilt. The red spot arrived on the meridian at the same time as Callisto passed underneath the planet but moving in the opposite direction. A very nice effect.