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: http://www.iki.rssi.ru/mirrors/stern/Education/wlopolar.html
Дата изменения: Unknown Дата индексирования: Fri Dec 21 22:04:06 2007 Кодировка: Поисковые слова: внешние рмбоефщ |
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(Files in red–history) Index 26. Polar Caps 26H. Birkeland, 1895 27. Aurora from Space 28. Aurora Origin 28a. Plus and Minus 29. Low Polar Orbit 30. Magnetic Storms 30a. Chicago Aurora 31. Space Weather 32. Magnetic planets 33. Cosmic Rays 34. Energetic Particles |
The space shuttle avoids polar orbits, because flying through the aurora exposes astronauts to radiation and creates other problems. But for studying the aurora, Birkeland currents, polar rain and other phenomena related to the distant magnetosphere, such orbits are very useful. For instance, although the DMSP spacecraft (above) were designed for military needs, scientists have also equipped them with magnetometers, particle detectors and other instruments, which have provided a great amount of scientific information. Different types of satellite orbits have different uses: while the synchronous orbit is best for communication satellites, Lagrangian point orbits help monitor the solar wind before it reaches Earth. A low altitude polar orbit is widely used for monitoring the Earth because each day, as the Earth rotates below it, the entire surface is covered. Typically, a satellite in such an orbit moves in a near-circle about 1000 km (600 miles) above ground (some go lower but don't last as long, because of air friction) and each orbit takes about 100 minutes. |
Next Stop: #30. Magnetic Storms
Author and Curator: Dr. David P. Stern
Mail to Dr.Stern: education("at" symbol)phy6.org
Co-author: Dr. Mauricio Peredo
Spanish translation by J. Méndez