Coronal Mass Ejections

CMEs in the News
CME Activities

Large flares are often associated with huge ejections of mass from the Sun, although the association is not clear. These coronal mass ejections (CMEs) are balloon-shaped bursts of solar wind rising above the solar corona, expanding as they climb. Solar plasma is heated to tens of millions of degrees, and electrons, protons, and heavy nuclei are accelerated to near the speed of light. The super-heated electrons from CMEs move along the magnetic field lines faster than the solar wind can flow. Rearrangement of the magnetic field, and solar flares may result in the formation of a shock that accelerates particles ahead of the CME loop. Each CME releases up to 100 billion kg (220 billion lb) of this material, and the speed of the ejection can reach 1000 km/second (2 million mph) in some flares. Solar flares and CMEs are currently the biggest "explosions" in our solar system, roughly approaching the power in ONE BILLION hydrogen bombs!

Fast CMEs occur more often near the peak of the 11-year solar cycle, and can trigger major disturbances in Earth's magnetosphere, known as space weather.

Click on the image to see a movie of a CME from SOHO/LASCO of an April 7, 1997 halo CME event. A "halo" event is one where the CME is headed in the direction of Earth. The dark disk in the center is not the Sun, but the occulting, or Sun-blocking, disk of the LASCO coronagraph.

MSU Coronal Mass Ejection FAQs


Back to Solar Activity

January 27, 2012: X1.8 solar flare and CME - 01.27.12 -- NASA
November 4, 2011: A 360 degree view of an X-class flare and a CME -- NASA
October 25, 2011: Beautiful red aurora -- NASA
October 5, 2011: Comet and CME on the sun -- APOD
September 20, 2011: Six CMEs in 24 hours -- NASA
July 24, 2011: Solstice flare and CME -- NASA
February 24, 2011: Monster prominence erupts from the sun -- NASA
November 8, 2010: Scientists unlock the secrets of exploding plasma clouds on the sun -- Eurekalert
September 21, 2010: Solar storms can change directions, surprising forecasters -- Science@NASA
August 19, 2010: Warning for solar flares -- Science News
August 4, 2010: Spacecraft observes coronal mass ejection -- NASA
May 26, 2010: NASA probe spots huge plasma ejections -- Physics World
April 18, 2010: Large eruptive prominence imaged by STEREO -- APOD
April 14, 2010: Scientists track solar explosion all the way from the Sun to Earth -- Astronomy
April 12, 2010: Magnetic 'ropes' tie down solar eruptions -- Astronomy
October 26, 2009: MESSENGER gets closest-ever look at solar-flare neutrons -- Astronomy.com
August 26, 2009: Unusually cold material found inside ICMEs -- ACE News
May 19, 2009: Stealth storm erupts from the Sun -- New Scientist
May 15, 2009: STEREO spies first major activity of Solar Cycle 24 -- NASA
April 14, 2009: NASA's STEREO spacecraft reveals the anatomy of solar storms -- NASA
April 14, 2009: The surprising shape of solar storms -- Science@NASA
April 14, 2009: Capturing a solar storm in 3-D -- JHU APL
April 14, 2009: The surprising shape of solar storms -- Science@NASA
April 14, 2009: Photos: Solar explosions revealed by twin spacecraft -- National Geographic
January 26, 2009: Acceleration of multiple seed populations at CME-driven interplanetary shocks near 1 AU -- ACE News
July 29, 2008: Timeline: The 1859 solar superstorm -- Scientific American
May 27, 2008: Cartwheel coronal mass ejection -- Science@NASA
January 21, 2008: Ring around the Sun -- NASA HEAPOW
November 26, 2007: Outburst pulls magnetic slingshot -- Astronomy.com
October 3, 2007: Comet Encke's tail ripped off -- APOD
October 1, 2007: NASA satellite sees solar hurricane tear comet tail off -- NASA GSFC
October 1, 2007: The Sun rips off a comet's tail -- Science@NASA
September 14, 2007: New film opening in Boston gives first 3D look at the Sun -- NASA GSFC
August 31, 2007: Celebrating 10 years of ACE in space -- ACE News
May 30, 2007: Radio 'screams' from the Sun warn of radiation storms -- EurekAlert!
May 30, 2007: News from your favorite star -- Astronomy.com
May 29, 2007: Screaming CMEs warn of radiation storms -- NASA GSFC
March 2, 2007: Space weather in STEREO -- Astronomy.com
February 6, 2007: Sun storm: A coronal mass ejection -- NASA GSFC APOD

CME news from 2006 and earlier

Grades 7 - 9: Anatomy of a CME Storm -- NASA IMAGE
Grades 7 - 9: CME Plotting Activity -- NASA IMAGE
Grades 7 - 9: Solar Activity and Coronal Mass Ejections -- NASA IMAGE