August 8th, 2011
04:12 PM ET

Coronal Mass Ejections

A coronal mass ejection, or CME, is a burst of solar winds, plasma and magnetic fields released into space. CMEs are sometimes associated with solar flares and other activity. If a CME reaches Earth, it's referred to as an interplanetary CME. On Earth, such activity can interrupt radio communications and damage satellites and electrical transmission lines.

CMEs reaching Earth can also produce strong auroras around Earth's magnetic poles, known as the Northern and Southern Lights.

Read more on coronal mass ejections.

Filed under: Glossary
soundoff (5 Responses)
  1. Hanane

    First-ever movie of comet's death plunge into sunEarthSkyNew sun-grazing cotmes appear every few days to scientists with the right equipment to see them. But – until recently – these same scientists said they'd never seen a comet's final moments just before plunging into the sun. Then on July 6, 2011, Comet Seen Vaporizing in Sun's Atmosphere—A FirstNational GeographicComet's fiery plunge may tell us how planets formChristian Science MonitorComet Hits Sun, Captured In Space Video For First Time (VIDEO)Huffington PostDaily Mail -Zee News -ABC Onlineall 109 news articles // 2012 Malaysia st_ro_start(27949, "", "", ""); Powered by RackTheme

    October 10, 2012 at 7:40 am |
  2. ajd041

    @Andrew you are correct its a rare event and steps can be taken but a cme can reach earth in as little as a day this isn't that much time to react and those who can shut off the power will most likely not do it due to legal obligations which then creates the disastrous event I mentioned above but what made me mad is that CNN didn't elaborate more on what these things have the potential to do

    August 11, 2011 at 11:59 pm |
  3. Andrew

    CMEs tend to be more significant if the leading edge magnetic field is southward and they're moving fast so that the leading edge magnetic field is amplified. These conditions open up the Earth's magnetic envelope (the "magnetosphere") so that energy can flow in. Even then most of these CMEs just create nice light shows in the arctic and antarctic skies.

    Very rare CMEs can damage power plant output transformers, and there don't tend to be many spares of those transformers. However, the chances of large numbers of power plants being damaged at once is very low. We can detect Earthward CME launches from the Sun, and there are steps that can be taken to protect the electrical grid when a CME is inbound.

    My qualifications? This is closely related to my doctoral dissertation topic.

    August 10, 2011 at 10:15 pm |
  4. Solar Demon

    I have a feeling the sun might be a terrorist tryin 2 steal our freedom

    August 9, 2011 at 4:06 pm |
  5. ajd041

    Is that it? no reference to an event on earth? No mention of the fact that if a powerful one of these things struck earth that it could result in a global blackout leaving the entire earth without power for decades until more transformers are built no wonder I'm the only one to comment

    August 9, 2011 at 12:01 am |


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