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发表于2024-11-23
Prentice Hall Physical Science pdf epub mobi txt 電子書 下載 2024
In January 1983, the Infrared Astronomical Satellite (IRAS)<br >was launched into space. Its job was to observe the unwerse<br >through infrared sensors. Infrared is a form of light that is invisi-<br >ble to the human eye. Surveying the entire sky, IRAS discov<br >ered five new comets and a new asteroid. It examined galaxies<br >hundreds of times brighter than the Milky Way. It even probed<br >the gas and dust clouds between the stars. While scanning the<br >star Vegs, IRAS made an important discovery. A dusty ring sur-<br >rounds this star. As yet, matter in the ring has not clumped to-<br >gether to form planets. But the existence of the ring is the first<br >clear evidence that stars other than our sun may have planetary<br >systems.<br > Spectacular photographs of a universe never before seen<br >have been radioed back to the earth by IRAS, Scientists exampn-<br >ing the data have confirmed an amazing scientific fact All wsi-<br >ble objects--be they huge galaxies of stars or tiny particles of<br >matter floating in space--are made of the same matter thai is<br >found on the earth. Nowhere in the universe is there matter<br >unlike that which exists "at home." For even the fiery stars are<br >composed of the same basic materials as the air, the rocks, the<br >seas, and you!<br >
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Prentice Hall Physical Science pdf epub mobi txt 電子書 下載 2024