Seeing The Space Station

How to See the Space Station
by South Jersey New Online
Sunday September 21, 2008, 8:10 AM

Keith Johnson

The International Space Station is a large satellite, currently carrying a crew of three human beings, circling the Earth a little over 200 miles up. And you can easily see it in the sky this week.
Keith JohnsonIt doesn't appear in the same place at the same time every night. Some nights we don't see it at all. But starting this week, we'll have some good evening opportunities. The best thing about ISS passes is that you don't need a powerful telescope or 20-20 vision to do the observations: you just need a pair of eyes that work reasonably well.
The ISS looks like a bright star, often much brighter than any true star, drifting across the sky. It appears somewhere in the west, and moves toward some point on the eastern horizon, taking up to five minutes to traverse the sky. Yes, it moves in a direction opposite to the (much slower) motion of the Sun and stars from east to west. That's true of many satellites.

To see the Station, check the schedule below for the starting point of the pass, then for the ending point. Then notice how high up (in degrees above the horizon: remember your plastic protractors?) it will be at its maximum altitude, usually midway between the starting and ending points. This will give you a rough idea of its path across the sky.
Face the initial direction, and imagine how the dot will be moving. It will start out quite faint, because then we're looking mostly at the dark, unilluminated side, so you may not catch it right away. Sweep your eyes back and forth along the expected path until you can pick it out.
It will brighten dramatically as it progresses across the sky, until by the middle of the pass you can't miss it, for these bright events anyway. It will fade out slowly as it continues down toward the predicted ending point, but if you have an unobstructed horizon, you can follow it for a surprising distance.
Here's the schedule for the next few nights for South Jersey. I'm only including the easiest, brightest passes here. If you want to look for the more challenging events, I'll tell you how in a few moments. (See below for explanations of the terms marked with "*").
Sunday, September 21 (tonight!), 7:17-7:23 p.m. The ISS rises in the southwest (SW), moving up and to the left. It will reach its highest position in the sky (its maximum altitude*) a little more than halfway up (53 degrees above the horizon) in the southeast (SE). Finally, it will fade out in the horizon murk in the east-northeast (ENE), as it heads out over the Atlantic. This is quite a bright pass; an astronomer would assign it a magnitude* of -2.1 (yes, less than zero), brighter than any star.
Monday, September 22, 7:44-7:49 p.m. Rises in WSW, moving up and to the right this time; peaks at 40 degrees altitude in NNW; sets NE. Magnitude down to -1.1, which is significantly fainter (yes, fainter: the magnitude scale is upside-down*) than yesterday's pass, but still brighter than any visible star.
Wednesday, September 24, 7:02-7:07. Rises W; peaks a bit lower (36 degrees up) in NNW; sets NE. Magnitude only -0.8: still bright, but nothing like Sunday's appearance.
*Altitude: the apparent angular distance in degrees above the horizon, NOT the distance above the Earth's surface in miles. 0 is at the horizon; 45 degrees is halfway up; 90 is straight overhead, at the zenith.
*Magnitude: a scale of brightness that developed from a system invented centuries ago in ancient Greece. It's a bit different from the scales most of us are used to. For one thing, the smaller the number, the brighter the object. The brightest summer star is at 0 (zero); Jupiter has a magnitude of -2.4; Venus stands at -4. The faintest stars you can see with the unaided eye are at +6. One word of warning: the predictions listed here are usually underestimates, in the sense that the ISS is usually quite a bit brighter than the numbers indicate.
The ISS looks like just a bright dot. But it's actually a multi-room laboratory connected with passages, and sports multiple large solar panels that supply electrical power for life support and experiments. You can find more information about the ISS at www.nasa.gov/station.
The Station has been growing over the years. As a result, it's also been getting brighter, since it shines by reflected sunlight. This sometimes leads to an interesting event. Once in a while, the ISS will pass into the Earth's shadow while it's still some distance above the horizon. It then fades from view over a period of a few seconds. That doesn't happen for the passes listed here, but if you continue watching the station in future passes, you'll undoubtedly witness such a happening.
If you would like to see future predictions, or predictions for other satellites, go to www.heavens-above.com. Heavens Above is a marvelous Web site that will predict the ISS appearances, and many other satellites as well. When a Space Shuttle is in orbit, you can find out where to look for it at Heavens Above. You'll first have to choose your home town--satellite passes differ for different locations--but every city I've ever looked for is in the list, no matter how small. Once you've gotten to the proper page for your location, you can bookmark it in your Web browser.
There are dozens of satellites passing over every night. Most of them are faint enough that they're only visible from a dark location, so the next time you're vacationing in the Poconos or the Pine Barrens, bring along a printout from Heavens Above.
Being able to predict satellite passes offers you the opportunity to impress your friends. A few years ago I was leading a star party in a state park. I knew that, by chance, at a certain time that night, a particular satellite was going to reflect so much light to the ground, right where we'd be standing at the time, that it would momentarily become several times brighter than Venus. These are called Iridium satellites. They're quite spectacular, and you can find out details of their appearances at Heavens Above, too.
A few moments before the event was due to happen, I told my audience that I happened to know there was a UFO mother ship overhead, and that it was due to send a laser beam message down to secret alien agents on Earth. When the Iridium satellite flared up brilliantly for a few seconds, my reputation was made for the evening. (I did eventually explain to everyone what really happened).
State ethics codes force me to remind you that such shenanigans are NOT SUPPORTED by the university at which I'm employed, and your humble writer is not responsible for what might happen if you try this gag yourself. But seeing human-created machines flying overhead, at least one of them with people on board, is impressive and enjoyable, even if you don't use them for reprehensible purposes. Go out the next clear night when the ISS is going over and give it a try!
Astronomy is something anyone can do, to one extent or another. But it's easier to do with a little help. Now showing at the Edelman Planetarium is "The Rowan Universe," a multimedia portrayal of all the different facets of the astronomy program at Rowan University. In this public planetarium show you'll delve into some of the fascinating mysteries of the cosmos being investigated by Rowan astronomers. You'll accompany a class of school children on a dangerous trip into Jupiter's atmosphere. You'll find out why astronomy is one of the most popular science classes at the university.
"The Rowan Universe" plays on Saturdays at 7 p.m. through November 22. Admission fees are $5 for adults, $3 for children under 13, $3 for seniors over 60, and $3 for Rowan students. This show is most enjoyable for children over eight years of age. Come do some astronomy with us!
Also playing at the planetarium is the classic laser show "Laser Floyd: Dark Side of the Moon," on Saturday nights at 8:30 through November 22. Tickets for both shows go on sale at 6:45 p.m. Saturday nights. We do not sell advance tickets or take reservations.
The planetarium is located in the Science Hall on the main Rowan campus, on the north side of Route 322. Campus maps can be found at www.rowan.edu/maps/. More information about the planetarium is available at www.rowan.edu/planetarium/.
Keith Johnson is the director of the Edelman Planetarium at Rowan University. Questions about the night sky and astronomy in general are welcome, as are questions about the planetarium. Call (856) 256-4389, or email him at johnsonk@rowan.edu.
Source: New Jersey Local News