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第一篇:Small But Wise
On December 14,NASA1 blasted a small but mighty telescope into space. The telescope is called WISE and is about as wide around as a trashcan. Dontlet its small size fool you:WISE has a powerful digital camera, and it will be taking pictures of some the wildest objects2 in the known universe,including asteroids,faint stars,blazing galaxies3 and giant clouds of dust where planets and stars are born. Im very excited because were going to be seeing parts of the universe that we havent seen before,said Ned Wright, a scientist who directs the WISE project.
Since arriving in space,the WISE telescope has beencircling the Earth,held by gravity in apolar orbit4(this means it crosses close to the north andsouth poles with each lap5).Its camera ispointed outward,away from the Earth,and WISE will snap a picture of a different part of the sky every 11 minutes. After six months it will have taken pictures across the entire sky.
The pictures taken by WISE wont be like everyday digital photographs,however. WISE Wide-field stands forWide-field Infrared Survey Explorer.As its name suggests,the WISE camera takes pictures of features that give off infrared radiation6.
Radiation is energy that travels as a wave. Visible light, including the familiar spectrum of light7 that becomes visible in a rainbow,is an example of radiation. When an ordinary digital camera takes a picture of a tree,for example,it receives the waves of visible light that are reflected off the tree. When these waves enter the camera through the lens,theyre processed by the camera,which then puts the image together.Waves of infrared radiation are longer than waves of visible light, so ordinary digital cameras dont see them,and neither do the eyes of human beings.
Although invisible to the eye,longer infrared radiation can be detected as warmth by the skin.
Thats a key idea to why WISE will be able to see things other telescopes cant. Not everything in the universe shows up in visible ligh
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