Just by chance, I stepped outside last night for some fresh air and as I often do, I looked up. And just as I was looking to see what was visible from the backyard, a bright light was moving through the sky. My experience told me it was a satellite and not an airplane. I momentarily thought it might have been an Iridium flare, but the size seemed too large. So my guess changed to the ISS (International Space Station).
Once it had faded and moved into Earth’s shadows, I went back in to visit the Heaven-Above.com website which has transit times for many satellites, and confirmed that it was indeed the ISS and I just happen to catch the 20-30 seconds that it was passing overhead. I also noticed that we’re going to have a number of additional passes for the next 4 or 5 nights. Ann suggested I make this info available to members and the general public. Always interesting to see the ISS pass overhead. And if you have time to prepare, you could try using binoculars to see some structure.
So as a public service, I’m posting some of the upcoming ISS passes for your observing pleasure. Remember that for basic observing of the space station, you don’t need any equipment. It’s bright enough that when the skies are clear, you can see it with just your eyes – it will look like a bright airplane, but without the flashing coloured lights. (Binos and telescopes may allow you to see detail which you can’t do with just your eyes, but it’s harder to track when it moves across the sky).
How to read this info:
Date and Time should be fairly straight forward. The time shown is local for the Hamilton area using the 24 hour clock. The times shown are in the evening.
Mag – (Magnitude) this indicates how bright the ISS will be with larger negative numbers being brighter. Venus (presently in the Western sky after sunset) is currently about -2. So a -3 pass will be brighter than Venus.
Track – this is a rough guide where to start looking for, and the direction that the ISS will take as it crosses the sky. At the designated time, look in the specified direction at about 30 degrees above the horizon which is roughly where you should first spot the ISS. Then follow it’s path when it crosses the sky. Usually the brighter passes will become visible earlier and last longer, but at most a pass will only last a couple of minutes. Usually they are more in the 15-30 sec time frame. Some won’t get very high above the horizon (trees and houses could be a problem). Others will pass nearly overhead. For the “NW to NW” appearances, this indicates that the ISS will only appear briefly in the general NW area of the sky and not very high above the horizon.
Most of the brighter passes will occur this weekend and fortunately the forecast is expected to generally be good.
I’ve tried to simplify the info from the Heavens-Above website, so what’s listed below won’t be exactly as you would find on their site. More details and info can be found at:
Heavens-Above for Hamilton
This info is current as of Thu Aug 26.
Date Time Mag Track Notes Thu Aug 26 20:23 -2.4 SW to E won't get high in sky Thu Aug 26 21:58 -2.3 W to NE Fri Aug 27 20:50 -3.7 SW to NE will pass nearly overhead Fri Aug 27 22:26 -1.1 NW to NW appears just above horizon Sat Aug 28 21:17 -2.0 W to NE Sat Aug 28 22:54 -0.2 NW to NW appears just above horizon Sun Aug 29 20:09 -3.5 SW to NE will pass nearly overhead Sun Aug 29 21:46 -1.1 NW to NE won't get high in sky Mon Aug 30 20:37 -1.8 W to NE Mon Aug 30 22:14 -0.8 NW to N appears just above horizon Tue Aug 31 21:05 -1.1 NW to NE Tue Aug 31 22:41 -0.3 NW to NW appears just above horizon For the following dates, the ISS won't get very high above the horizon. Wed Sep 1 21:33 -0.9 NW to NE Thu Sep 2 20:24 -1.1 NW to NE Thu Sep 2 22:00 -1.1 NW to N Fri Sep 3 20:52 -1.0 NW to NW Fri Sep 3 22:27 -0.5 NW to NW
Hopefully there will be lots of clear evenings and you’ll have a chance to see the ISS. You don’t need a particularly dark location, just a clear view of the path. If you don’t have trees or home in your way, you can see the ISS from the city.
Happy hunting.
