Saturday, November 13, 2010

Catching Jupiter Live


Jupiter and some of its moons, roughly as viewable through my telescope at higher magnification (9mm) last night. This pic is part of a screenshot from my Starry Night software.


Labels for the moons as given in Starry Night. Thebe was too faint for us to make out last night through my telescope.

I have a 150mm Newtonian telescope made by Celestron that I haul out rather infrequently to check out various astronomical delights first hand. Last night I set it up for Jennifer's parents, my daughter and her boyfriend. It was the first time most of them had seen Jupiter and several of its moons live. My daughter and her boyfriend thought it was, just perhaps, cool. Jennifer and her parents showed a bit more interest.

I have wandered through the night skies often since my teens. The thrill of seeing far away objects in our universe is something special to me (especially spotting them for the first time). I recall, for example, the first time I ever saw Jupiter's moons, many years ago, in the cheap Meade refractor scope I owned at the time. I saw Andromeda for this first time with that scope. It was only a faint "puff" of light in the small refractor but it was mind-blowing none the same.

After admiring the wonder of the planet last night, I trained the scope over to our Moon to check our the craters and such. The moon is still in its first phase, not quite half-full yet. It is often a better view when its dark side is more evident and you can catch a bit of shadow along the lighted edge giving everything the impression of greater depth.

For initial viewing with my Celestron I usually make use of my 40mm eyepiece. Then I switch over to a stronger magnification, 9mm or 7mm, for a closer look. Last night we were able to detect a mountain range whose peaks shown in the sunlight but were actually a bit beyond the boundary of the dark side, extended into the darkness. Just a small sliver of detectable light separated perhaps 100 miles or so from the light side of the moon, yet still tall enough to reach up a grab the sun before the curvature of the moon pulled all peaks beyond the reach of light.

Of Jupiter we were only able to see one of the dark bands on its surface last night. It was not as clear as the pics I have posted above which, of course, are not from my telescope but from my Starry Night program. The pics are, however, fairly representative of the size of Jupiter as seen through my 9mm eyepiece at precisely the time I was outside watching the planet.

One reason I don't get my telescope out very often is the ease and convenience of seeing everything through Starry Night. I know that sounds fairly lazy and I suppose I am a bit of a lazy astronomy geek. There is really no substitute for seeing the real thing live.

But Starry Night allows me the check out any part of the sky at any time regardless of cloud cover or wind conditions or temperature. One of my favorite uses of the software is to view the sky maybe a couple of hours ahead in time, spot various satellites that will pass overhead, then go out later at the appointed time with my binoculars or just my naked eye and watch for these human-made objects as they pass my way while circling the earth. I don't that rather often, actually, in winter.

Starry Night informed me last night that Jupiter was about 4.34 AU distance from us. An Astronomical Unit (AU) is the basic unit of measurement for near-objects like the planets. Jupiter was roughly 403,000,000 miles away from us as we saw its bright, distinctly round surface last night. An amazing distance when you consider how clearly it could be seen, even if its own brightness washed out much of the detail of its gigantic, stormy surface bands. At that distance, the light from Jupiter takes over 30 minutes to reach the Earth. So, we were seeing at our Solar System's largest planet not in the Now, technically, but only as it was a half hour ago.

If I had been more enterprising I could have used some of my filters to manipulate the visible light so that we could have seen another band or two on the surface but, like I said, I'm a rather lazy astronomer. I could see it clear enough in Starry Night for my satisfaction. And my fellow stargazers last night were impressed enough with what they were able to see. Most of them were chilled and ready to go back inside after about 15-20 minutes.

I like my Celestron telescope, but I made a mistake in trading for it. I bought my first reflector scope back in 1994, my first winter on my property. It was a standard Meade 10-inch cardboard tubed reflector. (This telescope is no longer made. It has since been replaced by a very attractive looking alternative that uses light-weight rods instead of a cardboard tube.) It was great fun star-hopping with that Meade. I could see details within star clusters and nebula that the 6-inch aperture of the Celestron simply doesn't pull in. It is the physics of optics. But, the Celestron is much easier on my back in terms of setting it up and its optics are technically better than the Meade's. The problem, though, is the aperture. Size does matter regardless of the quality of the mirrors, the precise adjustment controls, the fine craftsmanship.

That Meade scope and I connected with the live sky a lot back then. I have rather sophisticated deep-sky charts and 10-inches brings in considerable light if the sky is, ironically, dark enough. No city background light. I traversed many of the of what Messier catalogued. Seeing these distant space objects, light -years away, whose light I was seeing as it was before I was born, was and remains and sense of wonder to me.

But, it was fun last night standing in the chilled early evening watching Jupiter through my Celestron and counting what moons we could see. It was a true explorer moment. The inspiration that is inherently astronomy.

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