People waking up on Christmas morning to find a piece of the sun missing will be relieved to know that Santa didn聮t give it away as a gift. Rather they will be seeing the final solar eclipse of the second millennium.
麻豆视频 40 percent of the sun will be covered at the peak of the partial eclipse, when the moon passing between the Earth and sun will cast a shadow over Colorado, according to experts at the Sommers-Bausch Observatory at the University of Colorado at Boulder.
While the observatory won聮t be open on Christmas day, viewing the eclipse at home is easy, according to Keith Gleason, manager and laboratory coordinator at the Boulder observatory.
"First and foremost, don聮t look at the sun with your naked eyes," he said. "If you want to look at the sun during the eclipse, you need to purchase a pair of aluminized-mylar cardboard eyeglasses made specifically for looking at the sun."
Gleason said such glasses reflect away more than 99.999 percent of the sun聮s visible, infrared and ultraviolet light, dimming it enough for safe viewing. But, he said, make sure the glasses have been tested and determined to be safe for solar viewing. They can be purchased at many museum gift shops, hobby shops or stores that sell telescopes.
Another way to observe the sun during the eclipse is to take two sheets of ordinary paper and punch a hole in the middle of one of them. Once outside, hold the paper with the hole flat toward the sun, while putting the second sheet in the shadow of the first. The sunlight will pass through the hole and form an image of the sun on the second sheet of paper, Gleason said.
The eclipse will last more than two hours, and will begin about 8:30 a.m. MST. Peak coverage will occur at about 9:45 a.m., when the sun will appear to be 40 percent covered by the moon. The eclipse will be completely finished at about 11:05 a.m.
An eclipse of the sun only occurs with a new moon 聳 when the moon passes between the Earth and sun. The eclipse is actually the moon聮s shadow sweeping across the surface of the planet. While a new moon occurs every 29.5 days, a solar eclipse is rather rare because the sun, moon and Earth must line up in essentially a straight line, according to Gleason.
"Scaling it down a bit, think of the Earth as about the size of a standard desk globe and the moon orbiting the Earth 30 feet away as about the size of a softball," Gleason said. "It聮s the shadow cast by the softball that must fall somewhere across the surface of the globe 聳 30 feet away 聳 before an eclipse occurs."
The moon typically passes as much as 5 degrees above or below the sun at new moon, Gleason said, which means its shadow usually misses Earth.
People in the United States (excluding Hawaii and Alaska), Canada, Mexico, Central America and the Caribbean will be able to see the partial eclipse on Christmas morning.
Sommers-Bausch Observatory is located just east of Fiske Planetarium along Regent Drive on the CU-Boulder campus.
For more information about the eclipse visit the observatory聮s Web site at .