Thursday, September 3, 2009

What a show!

Wow, what a night! That's the kind of thing we amateur astronomers live for.

One of Jupiter's rarest shows was scheduled to begin. I had a choice of two scopes, my prized 200mm Schmidt-Cassegrain catadioptric telescope or my less-used 80mm refractor. I decided to give the refractor a workout this time around and it was well worth it!

Of course there are some, well, not rules so much as guidelines one should follow in basic backyard astronomy and one near the top of the list is don't observe over nearby buildings if you can help it. They radiate heat and that can muddy the view. Sadly, a large strip mall sits to my south and, since I don't have a car, I have to contend with it and that giant sodium lamp. Oh, how I wish I had an air, not that I would condone acts of vandalism. That would be wrong, of course.

Anyway, I got my first look at Jupiter around 10:30 p.m. Three of Jupiter's moons remained in sight. Io was heading towards eclipse behind Jupiter and Europa and Ganymede were paired off and heading on their way to pass in front. Callisto was nowhere in sight. And just a hint of the Great Red Spot, a very difficult thing to make out in a small 'scope.

I settled in for the long haul.

By 11:45, Io began to kiss the edge of Jupiter as I watched it slowly slide in behind...a tiny bud of light that melted into the main body of the planet. That was followed on the other side about 15 minutes later by Europa beginning its incursion in front of Jupiter. It slowly melded its light into the body of the planet, however, I was able to follow it past the merger for several minutes.

That left Jupiter with only one moon visible: Ganymede. Ganymede is further out from Jupiter than Io or Europa so, naturally, it moves a little slower. By 12:45 a.m., it was starting to move in front of Jupiter but it wasn't in a hurry. After getting up and moving around a bit, I went back and watched as the bright dot of Ganymede against the backdrop of space became the dark spot of Ganymede against the white clouds of Jupiter.

However, there was something "odd" about this spot. It seemed...elongated. Of course, as Ganymede began to cross Jupiter's disk, so did Europa's shadow so the two of them moved together in tandem for a while, separating after about an hour or so.

I continued to watch the show, occasionally looking up at the occasional snap or rustle nearby. I kept an open nostril to the air with the possibility of a malodorous visitor in mind. It's amazing how still one can become when one sees that black and white flash nearby. Luckily, such was not the case. But a representative of my vote for the next dominant species did amble across the fence - a racoon. Opposable thumbs make all the difference.

Needless to say, by 2 a.m., I was getting tired. But the show continued. I would occasionally take a look at the moon floating nearby. Talk about your contrasts. The solar systems largest planet a mere spark of light while our own, relatively insignificant moon dominating the night sky. But it's all perspective. After all, the moon has the advantage, being only 300,000 kms away. Jupiter is over 600 million kms.

The 'seeing' was mediocre at best and Jupiter experienced brief moments of clarity between jumping around in the air currents. I've seen astronomy described as being like birdwatching from the bottom of a pool. It's an apt description.

I had my best views at around 91-times magnification. I also experimented with filtering, finding the Wratten 11 still my favourite Jupiter filter. The clouds band details just seem to "pop."

By 2:21 a.m., Io was beginning to re-emerge and Jupiter was about to cease its "moonlessness." Meanwhile, Jupiter was heading for some trees, so I decided it was time to pack it in and go to bed.

As I'm writing this, it's now later in the morning and I'm feeling a bit sleep deprived and waiting for my first cup of tea to kick in. Still, it was an awesome show and I wouldn't have missed it for the world! Or worlds, as the case may be.


  1. In the end fatigue caught up with me too quickly and I had to get up the next morning...ah poopy. I was also battling dew. And the balance of real poor seeing and me creating poor seeing with too high a heat. Need a dew shield.

    Nice report!

  2. Thanks Marc. I was kinda protected from dew, plus I had my home made header going with the Kendrick controller. And, of course, the damn strip mall in front of me. Still, wow! What fun!

  3. Hey Andrew, your write up captures alot of things about astronomy that are really required to enjoy this stuff. Patience, prepartion, persistence, and perserverance with tiredness, weather,faulty equipment etc. But the pay off is awesome like last night! Glad it was fun for you!