View Full Version here: : Calsky help? ISS crosses moon in Brisbane Friday evening
16-03-2011, 06:26 PM
I received an email from calsky indicating that the ISS will be visible crossing the moon on Friday night at 6:58pm.
I'm new to using calsky and I'm just wanting some help to make sure I'm reading the alert right.
See the alert and map view below.
Does the map mean that although I'm not on the central path, the path is 11km wide so I'll still be able to view it? (see my little house icon on the map :))
Or is the alert just saying I'm close?
Hope the weather is good and someone gets to view this! :)
16-03-2011, 06:45 PM
Yes Dave, you will be able to see it. You are correct - the path width is 11.31kms wide, so if you are living within 5.65ks or so of the centreline on the map, you're in!
Are you planning to image it or try to watch it? Watching it might be a challenge if the ISS is not visible on approach. The actual transit happens very quickly, so if you can see it coming and follow it in you stand a chance.
Both transits of the Sun that I've captured were hard to pick by eye (on the computer screen). The first was close to the centre of the Sun and I thought I saw it, but the second was closer to the edge and I thought I missed it, but found it later going through my videos frame by frame. I think I've tried to capture 2 lunar transits and been unsuccessful both times.
16-03-2011, 07:28 PM
Sure is hard, believe me, and lunar is simpler as you can see it approaching, whereas daylight means you need accurate timing, well that's how I did it.
16-03-2011, 09:18 PM
That's just it, Gary - you can't always see the ISS approaching the moon either. It just depends on the ISS being out of the Earth's shadow.
16-03-2011, 10:13 PM
Thanks Guys, that sounds great! I plan to image it and I'm hoping I'll be able to see it approaching. But the weather forecast isn't good. I'll be able to shoot at 5 frames per second so if I can see it approach I should catch a few frames of it.
Any idea how fast I should make the shutter speed to eliminate motion blur?
17-03-2011, 06:59 AM
I think I worked out that for my DMK 41 (4.95um pixel) I needed to be faster than 1/225s to stop the ISS through my ED80. The longer your focal length, the faster you'll have to be.
18-03-2011, 06:05 PM
:sadeyes: Nothing but dense clouds.... :(
18-03-2011, 10:28 PM
But thanks for letting us know. It was nice to know I was on the direct path and have a few happy moments working out how best to record the event. I am better prepared because of it.
Next time - Ho Humm...
18-03-2011, 11:06 PM
Yep, me too... next time :) I seem to get an alert for a sun or moon crossing every few months, so its not a super rare event. But this was certainly one of the best ones, moon high in the sky, crossing through the centre, not in daylight etc.
Next time.... next time....
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