Look. Up in the sky it鈥檚 a bird, it鈥檚 a plane, it鈥檚 a "supermoon" and it鈥檚 disappearing. That鈥檚 because Sunday evening for the first time in 32 years a "supermoon," a moon that appears larger due to its close orbit to the Earth, and a total lunar eclipse are happening at the same time. But don鈥檛 worry about missing it, says Doug Duncan, a CU-Boulder astrophysicist and director of the Fiske Planetarium on campus.
鈥淎nybody on the night side of the Earth can see that eclipsed moon," Duncan said. "People can see the eclipse of the moon from home - any place that you have a nice clear view of the eastern horizon - watch the beautiful full moon rising and it will rise almost mostly eclipsed."
A lunar eclipse happens when the Earth slides between the moon and the sun. But even as the Earth鈥檚 shadow covers the moon, the moon will appear red or orange, according to Duncan.
鈥淣ow an eclipse of the moon is interesting because the moon looks orange and that kind of surprises people," Duncan said. Why, if the moon is in our shadow, doesn鈥檛 it just look dark? And the answer is kind of fun. A little bit of light from the sun leaks around the edge of the Earth, passes through our atmosphere, it bends a little bit, and still manages to hit the moon.鈥�
And why is the moon orange or red and not blue like our atmosphere, you might ask? There鈥檚 a simple answer to that question, according to Duncan.
"Now everybody knows that the sky is blue although a lot of people don鈥檛 know why. The reason the sky is blue is that when light from the sun, which is white light, a mix of all the different colors, comes through our atmosphere the blue light tends to scatter. So it bounces all around and makes the sky blue but orange and red light can continue."
And the reason it鈥檚 called a 鈥渟upermoon鈥� is because the moon鈥檚 orbit is closest to the Earth than at other times making it appear about 10 percent larger and 30 percent brighter.
"The moon鈥檚 orbit around the Earth is not a perfect circle. It鈥檚 a little bit elliptical or egg shaped and that means sometimes the moon is closer or farther away," Duncan said. "And it doesn鈥檛 vary by too much 鈥� about 10 percent. But that is something that you would notice. And so it just so happens that the moon is on the close side and it looks a little bigger than average and that鈥檚 happening at the time of the eclipse."
Duncan says the eclipse will begin just as the moon crests the horizon 鈥� around 7 p.m. - but won鈥檛 be fully eclipsed for another hour. But unlike a solar eclipse you won鈥檛 need special glasses or gear to view it so feel free to stare directly at the moon 鈥� although binoculars or a telescope would improve the view.
"The eclipse of the moon is beautiful. It鈥檚 not intense. It can鈥檛 hurt you. You just find a nice place out on the lawn and you watch," Duncan said.听
While a "supermoon" or lunar eclipse is not unusual, having them happen at the same time is uncommon. According to NASA, there have been just five such events since 1900. In 1910, 1928, 1946, 1964 and 1982.
This is the last total lunar eclipse visible anywhere on Earth until 2018, according to Sky and Telescope. Americans will actually see a total solar eclipse in August 2017 before the next total lunar eclipse.
