tirsdag 29. september 2009

'' LOS ANGELES, Sept. 14 (Xinhua) -- U.S. researchers have for the first time discovered that the solar wind, a stream of energized particles that flows out from the sun, varies greatly in how it affects the earth's magnetosphere. As a result of the discovery, spacecraft, power grids and other modern facets of life could be made safer, according to researchers at the University of California in Los Angeles (UCLA). The mystery about how the solar wind interacts with earth's atmosphere had puzzled scientists for half century. The rate at which the solar wind transfers energy to the magnetosphere -- a highly magnetized region which surrounds and protects the Earth -- can vary widely, but what determines the rate of energy transfer was unclear, according to UCLA atmospheric scientists. "We thought it was unknown, but we came up with a major surprise," UCLA professor Larry Lyons said in a press release available here on Monday. Lyons said Heejong Kim, an assistant UCLA researcher and their colleagues analyzed radar data that measure the strength of the interaction by measuring flows in the ionosphere, the part of the Earth's upper atmosphere ionized by solar radiation. The results surprised them. Charged particles carry currents, which cause significant modifications in the Earth's magnetosphere. This region is where communications spacecraft operate and where the energy releases in space known as substorms wreak havoc on satellites, power grids and communication systems.''
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September 29, 2009 11:36:34 UT - Mission Day: 5051 - DOY: 272

20:45 UT: SOHO is in contact.
Current station: Canberra DSS-45 until 01:45 UT.
Next: Canberra DSS-34 at 01:45 until 04:45 UT.