Posts Made By: Rod Kaufman

Ron Oehlert said:

A rare triple moon event on Jupiter is underway now. The 1st moon and it's preceding shadow are already on the globe with two more to soon follow. Anyone else observing this event?

Originally Posted by Chuck Burton

Started observing Saturn with a 17.5" f/4.5 reflector at ~2:30 AM MDT. The sky was mostly clear, with some drifting thin clouds occasionally obscuring the view. The atmosphere was fairly turbulent, and as a result, it was difficult to discern Saturn's cloud bands except for fleeting moments of clarity. At about 3:20 MDT, observing at 360X through a Meade 5.5 UWA during one of those moments, the cloud belts snapped into focus and the perfect tiny black dot of Titan's shadow was clearly visible, east of Saturn's meridian.

Later, around 4:15 MDT, I was observing with a 4.5mm Delos at 445X. The air turbulence had subsided a bit, and Titan's shadow had moved very close to the meridian at this point, dancing in and out of view.

As an aside, I had also set up my 152mm f/5.9 refractor, a relatively cheap, fast achromatic scope that I use exclusively for wide field, deep sky observing. The chromatic aberration in this scope makes it entirely unsuitable for doing any lunar or planetary observing.  In between "squinting sessions," trying to see Titan's shadow in the 17.5", I would take a few breaks to look through the refractor at deep sky objects. I thought I would compare some 2" O-III filters that I have acquired over the years, made by various manufacturers. It was an interesting exercise. Maybe I'll do a review on that later.

Anyway, just for grins, I turned the refractor towards Saturn and dropped in the 4.5 Delos (200X in this scope). I was stunned by the sharpness, contrast, and clarity of Saturn in this scope. There was barely any perceptible CA, perhaps because Saturn is dimmer and slightly yellow? In any case, I think if this had been a better night, I might have been able to see Titan's shadow in this scope. I also think it might still produce a good image at 250X or even 300X. So, before the next Shadow Transit, I'll have to scramble to find a TeleVue PowerMate to test my theory.

I've been observing with telescopes for over 50 years, since the days of my childhood. I've observed many shadow transits of the Jovian moons. This was the first time I ever attempted to view a shadow transit of Titan. I was surprised by how much smaller Titan's shadow disc was, passing across the face of the planet. It was a thrill to actually see it!