Coronal mass ejection
From Wikipedia, the free encyclopedia
A coronal mass ejection (CME) is an ejection of material from the solar corona, observed with a white-light coronagraph.
The material consists of plasma consisting primarily of electrons and protons (in addition to small quantities of heavier elements such as helium, oxygen, and iron), plus the entrained coronal magnetic field. When the solar cloud reaches the Earth as an ICME (Interplanetary CME), it may disrupt the Earth's magnetosphere, compressing it on the dayside and extending the nightside tail. When the magnetosphere reconnects on the nightside, it creates trillions of watts of power which is directed back towards the Earth's upper atmosphere. This process can cause particularly strong aurora also known as the Northern Lights (in the Northern Hemisphere) and the Southern Lights (in the Southern Hemisphere). CME events, along with solar flares, can disrupt radio transmissions, cause power outages (blackouts), and cause damage to satellites and electrical transmission lines. The largest geomagnetic perturbation, resulting presumably from a "prehistoric" CME, coincided with the first-observed solar flare, in 1859. The flare was observed visually by Richard Christopher Carrington and the geomagnetic storm was observed with the recording magnetograph at Kew Gardens.
In the novel Congo, by Michael Crichton, a CME is what disrupts the transmission from the Congo research team's computers to the satellites and back to Houston.
[edit] Stereo mission
On 25th October 2006, NASA launched the Solar TErrestrial RElations Observatory (STEREO), two near-identical spacecraft which from widely separated points in their orbits will produce the first stereoscopic images of CMEs and other solar activity measurements. The spacecraft will orbit the Sun at distances similar to that of the Earth , with one slightly ahead of Earth and the other trailing. Their separation will gradually increase so that after 4 years they will be almost diametrically opposite each other in orbit.<ref>Spacecraft go to film Sun in 3D BBC news, 2006-10-26</ref>
[edit] See also
[edit] References
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| Image:Sun picture.png |
| Structure: Solar Core - Radiation Zone - Convection Zone |
| Atmosphere - Photosphere - Chromosphere - Transition region - Corona |
| Extended Structure: Termination Shock - Heliosphere - Heliopause - Heliosheath - Bow Shock |
| Solar Phenomena: Sunspots - Faculae - Granules - Supergranulation - Solar Wind - Spicules |
| Solar flares - Solar Prominences - Coronal Mass Ejections |
| Other: Solar System - Solar Variation - Solar Dynamo - Heliospheric Current Sheet - Solar Radiation - Solar Eclipse |
| The Sun is also occasionally referred to by its Latin name: Sol. |
de:Koronaler Massenauswurf fr:Éjection de masse coronale ko:코로나질량방출 pl:Koronalne wyrzuty masy
