During the next couple of weeks, North Americans will have many opportunities to see the International Space Station, due chiefly to a seasonal circumstance. From now through the beginning of July, nights are shortest and the time that a satellite in a low-Earth-orbit (like the space station) can remain illuminated by the Sun can extend throughout the night, a situation that can never be attained during other times of the year. Because the station circles the Earth about every 90 minutes on average, its possible to see it on several consecutive passes in a single night.
Because the space station revolves around the Earth in an orbit that is inclined 51.6 degrees to the equator, there are two types of passes that are visible. In the first case (well call it a "Type I" pass), the station initially appears toward the southwestern part of the sky and then sweeps over toward the northeast. About seven or eight hours later, it becomes possible to see a second type of pass (well call it "Type II"), but this time initially showing up toward the northwestern and sweeping toward the southeast.
During mid-May, because of the shortness of the nights, North Americans will get a chance to see the station in a series of Type I passes after sunset in the evening sky, then see it again the following morning before sunrise, undergoing a series of Type II passes.
From about May 7 through 10, only the Type II morning passes will be available for most North American locations. In some cases, the station might make as many as three such pre-sunrise trips. A good example is New York City, where, on the morning of May 10, the giant shining batch of metal will make three overflights beginning, respectively, at around 2:01 a.m., 3:35 a.m., and 5:10 a.m. Then, from May 11 and (depending on your location) until about May 14, it will be possible to see both Type I passes in the evening and Type II passes the following morning. For some locations, like Chicago on the night of May 13-14, there may be as many as five chances to see the station during a single night! For much of North America, the prime viewing period for both evening and morning passes will be from May 12 through 14. After May 14 or 15, the window of opportunity for the Type II morning passes will close and only Type I evening passes will be possible, and then only for several more days thereafter.
Watching the night sky is a wonderful family activity. Our family loves to watch meteor showers and hunt for constellations. There's nothing better than huddling under a warm blanket with your loved ones and watching the miracles of the night-time sky unfold before your eyes!
For more information, go to:http://www.space.com/news