Tuesday, September 2, 1997

Io Show Off!

I have been working long hours lately, and have not had much time to even step out the back door to observe. Last night I was out at 10:45 and 11:30, but the sky was soft and unsteady, so looking at the best backyard object (Jupiter) was not very satisfying.

I decided to leave the scope out back, as incentive to take a peek tonight. So, about 9:20 I went out, put in the 7.5mm and pointed the 10" at Jupiter.

Detail was coming and going, and of course, my eyes had not acclimated yet. I went inside to turn out some lights and see how Daniel was doing with his homework, when I noticed a present my parents had brought him years ago... a little Tasco refractor with the designation 30 x 30 on it. I was up for laugh. Outside I went, and held it like a pirates spyglass. After a while, I found Jupiter... a small cream colored dot in the midst of a reddish glow. What garbage! I sat the toy down, and took another peek in the 10"....

Suddenly the sky steadied and Jupiter was showing a very distinct shadow transit past the meridian right in the middle of the equatorial zone. Which of the three visible moons was it???? I would glance around, noting what I take to be the GRS on the southern belt, just in from the trailing edge. Around it, popping in and out of view, were three or four white ovals. Below (to the north) of the shadow transit, was a very, very dark line in the northern equatorial belt. It was a literal feast for the eyes!

As I sat enjoying the view, it suddenly dawned on me there was another distinct white oval... on the leading limb, well, almost on the limb, but it was not oval....

In a moment of clarity, there sat Io, just beginning to peek over the limb of the planet, its shadow following it across. I watched as the GRS, the shadow and Io all moved across. Soon, Io was a definite bump on the limb, then, just as quickly, it was breaking away from the Jovian background, revealing itself against the black of space. The shadow was now all that remained of the dual transit.

What a sight! It all took about 20 minutes, and satisfied my craving for some telescope time after a very busy day of work.

I watched for a bit more, enjoying the subtle color variations of the many zones on Jupiter's face. The GRS now was approaching the meridian,perhaps in another 30 minutes or so, along with the white ovals shepherding it. The shadow moved a bit more. The distance between Io and the planet increased.

The clouds began to approach, and I went in to write to you all. Maybe we'll have a good night at Montebello. My appetite has been whet.

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