By Brendan Loy
If the current mission schedule for the Space Shuttle Atlantis remains unchanged, much of the continental U.S. will have an opportunity to watch the Shuttle and the International Space Station fly overhead Sunday night as two distinct, bright dots, moving briskly across the evening sky in tandem -- two unmistakable beacons of the human presence in space. Just over 12 hours removed from their Sunday-morning undocking, they should be a very cool sight to behold.
Trust me: even if you're not into dorky stuff like Iridium flares, this is well worth a trip outside at the proper time, if the sky is clear. (And you don't need to be in a low-light-pollution location to see them. They're very bright. So long as you're not standing, like, directly under a streetlight or something, you should be able to see them, even from downtown in a major city. Basically, if you can see Venus, you can see the ISS and Shuttle.)
There are two viewing opportunities for the U.S. on Sunday evening: the first between 6:57 and 7:04 PM EST -- visible from much of the eastern half of the country -- and the second from 8:27 to 8:35 PM EST (that's 6:27-6:35 MST) -- visible from most of the Mountain Time Zone, and parts of the Central and Western time zones as well.
To find out if and when the flyovers will be visible from your particular location, go to Heavens-Above and select your location. When you get to the "Main Menu," click on "10 day predictions for: ISS" and look for the "17 Feb" entry (or entries) on the list. Click on it (or them), and you'll get all your local details, including precisely when and where in the sky to look. (The Shuttle will either be just behind the ISS or just ahead of it; I'm not sure which.)
Basically, though, the closer you are to the black lines in these graphics, the better your potential view is, provided it's after local sunset when the flyover occurs:
Don't pay much attention to the red circles; they just show the extent of potential satellite visibility, down to 10 degrees above the horizon, from the central location on each map. The circles would look different from other spots and at other times along the satellite's path. So what you really want to focus on is the black line, and how close you are to it. The closer you are, the brighter and more directly overhead the satellites will be. (Again, the other issue is the timing of sunset; the Pacific coast won't get a good view because the sun will still be up.)
But really, don't bother trying to speculate based on those maps -- seriously, just go to Heavens-Above and get the details for your specific location. :)
Here in Knoxville, we're pretty darn close to the black line for the earlier flyover, and as a result, we get a really great view: the ISS will have a magnitude of -2.1 (lower magnitudes are brighter; -2.1 is brighter than anything in the night sky except Venus and the Moon) and will reach an altitude of 67 degrees at 6:59:54 PM EST. Oh, and it'll pass directly through Orion about 35 seconds later.
(Unfortunately, the weather forecast for Knoxville looks less than promising at the moment. I hope it changes!)
The view is even better from Nashville, which is almost literally right on the center line, so there the ISS will reach an max altitude of 85° -- and a stunning magnitude of -2.5 -- at 5:59:23 PM CST.
A few other potential locations of interest to Irish Trojan readers: Phoenix (magnitude -1.9, altitude 39° in the NE sky at 6:30:38 MST), Denver (magnitude -0.3, altitude 28° in the SW sky at 6:30:37 MST), South Bend (magnitude -0.6, altitude 33° in the SW sky at 6:58:28 EST), Memphis (magnitude -2.1, altitude 46° in the NE sky at 5:59:00 CST), Atlanta (magnitude -2.5, altitude 74°, almost directly overhead -- right near Mars -- at 7:00:14 EST), Indianapolis (magnitude -1.3, altitude 45° in the SW sky at 6:58:49 EST), St. Louis (magnitude -2.5, altitude 88°, directly overhead at 5:58:22 CST, which is 17 minutes after local sunset), Washington, D.C. (a comparatively dim magnitude 0.4, altitude 19 in the SW sky at 7:00:17 EST; Virginia suburbs will be marginally better).
Oh, and in Southern California, although both of the flyovers mentioned here will occur before local sunset, you may be able to catch a glimpse in the southwestern sky (max altitude 19°) of the next flyover, over the Pacific Ocean, at 7:05 PM PST. The magnitude will only be 0.3, though, a little dimmer than Mars, so light pollution could be a problem.
Anyway... all of this is subject to change, particularly the precise schedule details, if the ISS's orbit gets tweaked a bit between now and then. Also, the undocking schedule could change; if it's delayed, and thus the Shuttle is still docked on Sunday night, then it and the ISS will appear as a single bright dot moving across the sky, which, while still pretty cool, is a much more commonplace occurrence.
However, assuming the undocking schedule remains relatively unchanged, I highly encourage everybody in range of this flyover to check it out Sunday night.
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