Spaceship sightings expected for weeks
(CNN) -- Determined night watchers in North America can experience a close encounter of the visual kind in the coming weeks, as a spaceship brighter than any star makes its way across the sky.
The craft will make repeated passes over the United States and Canada between late July and mid-August, at times surpassing in brightness all other nocturnal objects save the moon.
What is the object? The international space station (ISS), which will offer optimal viewing conditions during the late summer season for millions of observers.
During typical cameos in the sky, the multibillion-dollar ship appears as a dim point near the horizon, then quickly brightens as it glides across the heavens for anywhere from three to six minutes.
Veteran sky watcher Jim Young recently trained a small telescope on the modular complex from California.
"I followed the ISS with my 10-inch at home one night, and was quite surprised that I could see the shape and long solar panels quite well," he said.
"The color is vivid; whites, off-whites, and the gold color of the solar panels, switching to copper red as it moves down and away from the observer."
The naked eye cannot distinguish particular structures, but the orbiting outpost's steady glide across the sky delights nonetheless.
"It can vary from yellow-white to coppery-red, even to an observer looking with nothing other than his own two eyes," said amateur astronomer Ulrich Beinert of Germany.
It moves more slowly than shooting meteors, which race the sky in seconds at speeds of around 100,000 mph. The station still moves at a respectable pace, 17,000 mph, lapping Earth once every 90 minutes. Some liken its speed to that of a high-flying airplane.
"It's an experience that is hard to forget," Beinert said. "It barely seems to move when it is close to the horizon, still being more than a thousand kilometers away. And it moves with an incredible speed when it's directly overhead."
Interested? Then you need to know when and where to crane your neck. Three Web sites can calculate upcoming viewing opportunities in your area, just type in your zip code or city. The sites work for readers in other parts of the world as well.
Their predictions are generally accurate to within minutes, but one should double-check closer to actual viewing times for last-minute updates.
That is because the station can go slightly up or down in its orbital path, depending on the natural decay of its orbit or periodic boosts to higher altitudes.
Why does the station vary in brightness? It depends on how much sunlight bounces off of it. The light-colored ship can reflect back up to 90 percent of the light that strikes it, according to NASA.
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