Friday, November 12, 2004

An Interesting Few Weeks in Astronomy

Wow, what an interesting few weeks it has been for those of us who look to the sky for photos. At the end of October we had the total lunar eclipse (which we won't see again for 2.5 approximately years). I posted my collage of shots from that night a few weeks ago. That in itself seemed like an interesting event, and made me wish I had something with a bit more magnification power, or maybe even a telescope with a camera mount. But the fun didn't end there.

Last week we saw the conjunction of Venus and Jupiter, when the earth and those planets are aligned, causing them to appear very close together in the morning sky. Not any sort of grand event that you would notice unless you knew what you were looking at, but it seemed interesting to me none the less. Unfortunately, I did exactly that...I didn't notice it until I read about it after the fact. The closest day of the conjunction was Friday morning, but I didn't hear about it until Friday night. However, the planets move quite slowly, and by Saturday morning they would still be relatively close together. So with that, I got up early (5:30AM) and got to shooting. Shot through a 300mm zoom (on my Digital Rebel, that's a 480mm equivalent), you could just start to make out several of Jupiter's 4 largest moons. I thought that was quite fascinating. But again, just like the lunar eclipse, it only made me wish I had some more magnification power. Anyway, here are the results I got:

Just like shooting the moon, shooting stars is difficult, especially when trying to resolve the dimmer, tiny objects like the moons of Jupiter's. You need to get a lot more light onto the sensor, but long shutter speeds cause problems because of how fast objects move through the sky. More than a few seconds and you start to see star trails instead of stars. The above shot was done at f/5.6 at ISO 800 for only 2 seconds, and you can already begin to see the object are elongated.

Not to let the fun end there, the following week (actually, just 2 days later) we got to experience the strongest Aurora Borealis in...I don't know how long. Quite a while, from what I heard, but I wouldn't know since I've never seen them before. Of course, once again I found out about it just a little too late. The strongest occurrence was on Sunday night, and I read about it Monday morning (and kicked myself). I looked for it on Monday night, but no such luck. However, another flare on Tuesday caused the aurora to strengthen. I wasn't able to get out of the bright lights of the city, so I missed some spectacular sights, however I was able to see a faint glow in the sky. It took me several minutes of staring at it to realize I was in fact looking at my first aurora ever. I grabbed the camera for a long exposure to be certain, and this is what I got:

In retrospect, I shouldn't have taken such a long exposure. While the time lapse exposure does give a nice effect in showing a giant green blur in the sky, the aurora is constantly changing, so you lose all the detail. In that picture, you can just barely see the vertical stripes coming out of it, but in person, they were quite apparent. I should have opened up the aperture more (I could have gone 1 and 2/3 stops more) to get a faster shutter speed, and maybe even bumped the ISO up to 400 or 800. That would have given me an exposure around 2 to 5 seconds, and probably would have looked much better.

So, it was an interesting 3 weeks to photograph the sky. It makes me really want to get some better equipment, like an auto-tracking telescope. It also makes me wonder what will be waiting in the sky to be photographed next week?

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