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오늘의 이미지
James Montgomery Flagg used the familiar figure of "Uncle Sam" and thus created the most famous recruiting poster by the U.S. Army. From April 1917 to autumn of 1918 more than four million pieces of it were printed. Still utilized in more recent times, this print was probably made in 1975. Today is Veterans Day in the United States.
오늘의 미디어
Video of a solar filament of a coronal mass ejection being launched. Filaments are thread-like dense, somewhat cooler, clouds of material that are suspended above the solar surface by loops of magnetic field. Filaments can erupt fully or partially and these erupted material can be observed in form of coronal mass ejections which can collide with Earth's magnetosphere, where they can cause geomagnetic storms, aurorae, and in rare cases damage to electrical power grids.
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