Io Transit

[RobCos]

Jupiter and Io were the stars of the show tonight.........

Jupiter was located less than 10 degrees from the full moon. The effect was as is expected. A complete loss of contrast-at least in the wider field eyepieces such as my two inch 30mm and my favorite eyepiece that never disappoints-except tonight---my UO 25mm Super Erfle.

Tonight was a good night to try out my new Baader Moon and Skyglow filter. I stacked this filter with my Fringe Killer and the effect was remarkable. Contrast was vastly improved on the gas giant.

Three of Jupiters moons were lined up on the right. A fourth was missing. I would find out later that it was Io.

Popping in the UO 9mm, North and South Equatorial bands were nice and sharp. Contrast was improved once again despite the moons glare. I was getting somewhere.

Lo and behold, there was a sharp, black dot on the Northern belt just past center heading West. I was in a for a good night. Io was transitting tonight!

I popped in the 5mm and the planet was a tad softer-but the equatorial banding still stood out wonderfully. I could see a hint of the Northern Temperate band but nothing in the South.

Io was quite prominent as it made it's way across the Northern band. It's truly awesome sight to see the solar system "in action".

Could I bring out more detail with a color filter? Yes and no:

Yellow/Green 11: Wow. I had wondered if color filters were overrated but at least on a night like tonight they can come in handy. The sky was blacker just a tad with this filter and the planet was now standing out like a sore thumb. Even better the bands and Io were now twice as prominent in the eyepiece. Very nice.

Light blue 82A: Not a whole lot of improvement.

Orange 21:too dark for my little 80mm on this night. Just wasn't cutting it.

On to the transit:

I was speechless. Seeing Io's shadow reach the limb of Jupiter and then disappear--only to see the bright light of the actual moon appearing a few seconds later was an awesome sight. I could see Io's light barely touching the limb of the planet as it "pulled away" from where it's shadow had just disappeared only moments earlier.

Again, I highly recommend anyone who hasn't taken the time to watch a Jovian transit to it's completion to find the time and do it-you won't be disappointed! Patience is the key here as it takes time for the moon to cross. I only saw the latter half of the transit and I was out there for at least an hour and half(I think). Well worth the wait!

Rob C.