Observing Spotlight – Dropping In On Jupiter…


“Now that she’s back in the atmosphere, with drops of Jupiter in her hair…” Oh! Hey, there! Come on over and have a seat. Yeah, I really like that “Train” song, too. While the Moon is putting the brakes on deep sky observing, why don’t you take a look though the magnificent eye of the 9″ TMB refractor of Dietmar Hager and we world-wide friends can spend a little quality time together with Jupiter.

Here… You look through the eyepiece of a little telescope for awhile and I’ll tell you some of the things we know about this giant planet.

What’s that you say? Yes. Jupiter is big… Big enough to hold the mass of 1,000 Earths and about 1/10 the size of our Sun. Its a heavy-weight, too… But, believe it or not, Jupiter’s density is only about 1/4 of that of Earth’s. Scientists think this means the giant planet consists mostly of hydrogen and helium around a core of heavy elements. That means Jupiter more closely resembles a sun instead of a planet! Yeah… It’s hot there, too. As a matter of fact, Jupiter is putting out twice as much heat as it receives from Sol. Near the core temperature may be about 43,000 degrees F (24,000 degrees C)… Even hotter than the surface of the Sun. Hot enough to get a burn? Darn right. Those subtle tones of red and brown are chemical reactions much like what happens when we humans get a sunburn.

I see you smiling in the dark. Are you starting to notice details Jupiter’s cloud bands? Even a small telescope shows these areas called “zones”. This is where chemicals have formed colorful layers of clouds at different heights. The white belts are made of crystals of frozen ammonia and they are positioned much higher than the dark belts. Of course, you know all about the “Great Red Spot”, but sometimes it’s pretty hard to see unless you know when to look. Jupiter makes a complete rotation in about 10 hours, so even if you can’t see something right now – you can wait awhile and it will come around.

Speaking of coming around, did you notice how close one of Jupiter’s moon is getting to the edge of the planet? Then keep watching because we’re about to see a transit happen. Jupiter has at least 60 moons, but 4 of them are bright and very easy to see even in binoculars. They were discovered by Galileo, and that’s why you’ll sometimes hear them called the “galiean moons”. When they zip around behind Jupiter in their orbit, it’s called a occultation – but when they go in front of the planet from our point of view, it’s called a tranist. The really fun part is that you can not only see the little moon going across the surface, but a few minutes later? You can see the shadow, too! Here’s a little bit of magic from another friend of ours named Sander Klieverik.

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Isn’t that just the coolest? You’re going to be hearing a lot about Sander’s work here in the near future. And there’s going to be a great Jupiter event he wants to make sure you know about!

“On October 31, 2010 Europa and Ganymede will simultaneously cross the cloud tops of Jupiter from 02:26 till 03:21 UT as do their shadows from 04:17 UT till 07:00 UT. Timing of entrance of the first moon, Ganymede will be around 00.20 UT, following by Europe at 02:26 UT. The first shadow will appear 04:09, quickly followed by Europe’s shadow at 04:16. Two shadows in very close proximity should be a very beautiful view! Circumstances are favourable as Jupiter has a visual diameter of around 48 arc seconds, being a month after opposition in which Jupiter reached almost 50 arc seconds (minimum 33″). For the non-astronomers, when a planet is in opposition it is roughly closest to the Earth at this point of its orbit, making it appear bigger and brighter. At that moment it is visible almost all night, rising around sunset, culminating around midnight and setting around sunrise.”

In the meantime, why don’t you keep practicing timing galiean events and seeing them? Here’s a handy Jupiter Moon Tool, and Sander has also prepared a Jupiter Almanac as well!

“But tell me, did the wind sweep you off your feet? Did you finally get the chance to dance along the light of day… And head back to the Milky Way? And tell me, did Venus blow your mind? Was it everything you wanted to find? And did you miss me 1hile you were looking for yourself out there?”

Now, quit bogarting that eyepiece… It’s my turn!

Many thanks to the one and only Dietmar Hager, Jupiter Video courtesy of Northern Galactic and the up and coming Sander Klieverik’s “AstronomyLive”. Song lyrics – “Drops of Jupiter” are from the artists “Train”. Let’s keep on rockin’ the night!

5 Replies to “Observing Spotlight – Dropping In On Jupiter…”

  1. Funny, I couldn’t figure out what was that huuuge star under Pisces’ head. Now I know it’s Jupiter.

  2. OK, you know how this goes. You start to mention drops in her hair and quality time, and all I can think of when I see that first image is “wow, you present such a huge pair”. Bloody testosterone reaction!

    But yes, Jupiter is still “a little miniature solar system” and a couple of extra traits thrown in as well. It may be that the internal structure and high pressure materials is a lot more inspiring than the sun, who learned us about spectroscopy, fusion and neutrino masses. Star Trek had its dilithium, but what will we have? But it’s well worth a look anyway!

  3. Always a favorite! During my recent viewing of the Perseids a car stopped by my roadside spot with a couple fellers in it. They saw my telescope(s) and asked, “Hey, whatcha looking at?” I asked if they wanted to park and take a look and/or watch the meteors, they declined, saying they were headed into town on a ‘brew run’ and couldn’t afford the time? (Too bad) Then the driver asked me what that “bright star” over there was? I told him it was actually Jupiter.. he was amazed. “So that’s Jupiter, eh? It’s SO bright!” Well.. Jupiter convinced them that they DID have the time, so they parked and took a look. They ended up staying for an hour or so.. forgetting all about their ‘mission’! LOL!

    Moral: Some people go to bars.. and some people look at the stars!

  4. Usually, in my 4″ Schmidt Cassegrain, I can see the four brightest moons of Jupiter. BUT have on occasion, during nights of ‘good seeing’ at my 1,500 foot elevation astronomy spot, been able to see seven of the moons! This means that ‘seeing’ is everything as far as Jupiter’s moons go. Spending time at the eyepiece is key here as there will be moments of ‘good to excellent seeing’, that is when the atmosphere cooperates and suddenly becomes very transparent. Using ‘averted vision’ helps too. That’s when you don’t look directly at the object you are viewing but look slightly ‘off center’. This uses the rods and cones in your eye that you don’t normally use and which aren’t quite as ‘worn out’… Try it and you will ‘see’ what I mean!

    Tammy… I don’t mean to intrude into your good works but included the above tips anyway after reading of Jack Horkheimer’s passing. He was always full of tips and suggestions for improving one’s star gazing. The above is my humble attempt at carrying on those good works! [email protected]; )

  5. aqua? you go right ahead and give observing tips! when i get reactions and comments like this, it really is like having your friends around you in the dark enjoying the cosmos. when i write a article, it comes from inspiration and amazing coincidence. in this case it was the work of a well-loved and talented friend… and the train stopped and let off a very unique UT reader who gave me back hope and a mission. what happens when they combine is that i’ll start to write…. and not know when to quit! fraser never limits the amount of words i use, but i imagine you readers might like me to get to the point in something a little less lengthy to read than “War and Peace”, eh? giggle…

    the 3D image was totally amazing to me, because (even as much as i have worked with them) i didn’t realize what it was at first. i had the image up on my laptop screen and looked away. when i came back to it, there was that split second when my eyes were refocusing and jupiter just slammed out of the screen! 3D is also an effect when you view the galieans, too. if you go “eye easy” when studying, it’s very easy to see which moons are towards you and which are behind the planet. even cooler is when you have an opportunity to use a really BIG telescope and can perceive limb darkening on the satellites. and yes! a 4″ SCT is an awesome planetary observing tool and i have no doubt that you’ve probably seen even more that 7! (wasn’t it e.e. barnard, as an amateur, who discovered the next 3 with a relatively small telescope?)

    see? i’m babbling again.


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