NASA's Cosmicopia -- Sun -- Earth's Magnetosphere

In spite of its low density, the solar wind, and its accompanying magnet field, is strong enough to interact with the planets and their magnetic fields to shape magnetospheres. A magnetosphere is the region surrounding a planet where the planet's magnetic field dominates. Because the ions in the solar plasma are charged, they interact with these magnetic fields, and solar wind particles are swept around planetary magnetospheres. Life on Earth has developed under the protection of this magnetosphere.

The shape of the Earth's magnetosphere is the direct result of being blasted by solar wind. Solar wind compresses its sunward side to a distance of only 6 to 10 times the radius of the Earth. A supersonic shock wave is created sunward of Earth somewhat like a sonic boom. This shock wave is called the bow shock. Most of the solar wind particles are heated and slowed at the bow shock and detour around the Earth. Solar wind drags out the night-side magnetosphere to possibly 1000 times Earth's radius; its exact length is not known. This extension of the magnetosphere is known as the magnetotail. Many other planets in our solar system have magnetospheres of similar, solar wind-influenced shapes.

More about the magnetosphere...

Still more about the magnetosphere...

Dynamic modeling of the Earth's bow shock and magnetopause -- Real time data from the ACE spacecraft are used to predict the shape and location of these boundaries at the present time and into the near future. -- from Polar/PIXIE

QuickTime movie of the effects of space weather on the magnetosphere -- UCLA

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Earth's Magnetosphere in the News:

January 8, 2009: Magnetic fields could reveal exoplanets -- Physics World
January 7, 2009: "Warm plasma cloak" discovered enveloping Earth -- National Geographic
December 16, 2008: Sun often "tears out a wall" in Earth's solar storm shield -- NASA THEMIS
December 15, 2008: A giant breach in Earth's magnetic field -- Science@NASA
October 30, 2008: Magnetic portals connect Sun and Earth -- Science@NASA
September 25, 2008: Lava flows reveal clues to magnetic field reversals -- University of Wisconsin - Madison
August 28, 2008: Cluster watches Earth's leaky atmosphere -- ESA
July 19, 2008: Asteroid switched Mars' magnetic field on and off -- New Scientist
July 10, 2008: Enhanced color Caloris -- APOD
June 30, 2008: Earth's core, magnetic field changing fast, study says -- National Geographic
June 23, 2008: XMM-Newton watches lazy pulsar being jazzed up by companion -- ESA
June 4, 2008: Iron snow behind Mercury's magnetism -- Scientific American
June 2, 2008: Building a baby Earth to test its magnetic field -- NPR
May 8, 2008: Iron 'snow' helps maintain Mercury's magnetic field -- Astronomy.com
April 30, 2008: Team of researchers explain how birds navigate -- ASU
April 30, 2008: 'Chemical compass' created -- Nature
April 28, 2008: 'Broken heart' image the last for NASA's long-lived Polar mission -- NASA GSFC
April 17, 2008: The moon and the magnetotail -- Science@NASA
March 13, 2008: Japanese satellite first to use magnetic memory -- Scientific American
March 9, 2008: New discovery at Jupiter could help protect Earth-orbit satellites -- Eurekalert
February 25, 2008: Killer electrons surf celestial tsunamis -- NASA GSFC
February 1, 2008: The first Explorer -- APOD
January 31, 2008: New discovery on magnetic reconnection to impact future space missions -- Science Daily
January 30, 2008: Mercury's magnetosphere fends off the solar wind -- Eurekalert
December 31, 2007: Titan's plasma wake (see #16) -- Eurekalert
December 20, 2007: News from Earth's magnetic field -- Eurekalert
December 13, 2007: Earth's protective magnetic field -- Astronomy.com
December 13, 2007: Earth's magnetosphere: On the ropes -- Sky & Telescope
December 11, 2007: Earth's magnetic field could help protect astronauts working on the moon -- Eurekalert
November 28, 2007: UNH scientists report first findings on key astrophysics problem -- Eurekalert
October 3, 2007: Comet Encke's tail ripped off -- APOD
September 12, 2007: Cluster and Double Star uncover more on bright aurorae -- Science Daily
August 22, 2007: What makes Mars magnetic? -- Spaceflight Now
August 1, 2007: Mmmm, space chips -- Popular Science
June 1, 2007: Pioneering 3D view of near-Earth magnetic 'dance' -- Science Daily
April 13, 2007: Cluster sees tsunamis in space -- SpaceDaily
March 29, 2007: Magnetic fields get reconnected in turbulent plasma too, Cluster reveals -- SpaceDaily
March 12, 2007: Cluster opens a new window on 'magnetic reconnection' in the near-Earth space -- EurekAlert!
February 20, 2007: Lockheed Martin scientists determine magnetic reconnection locations at Earth's magnetopause -- SpaceDaily
February 9, 2007: Cluster - new insights into the electric circuits of polar lights -- European Space Agency
January 24, 2007: Storm hunt: spacecraft quintet to track down magnetic field tempests -- Space.com

Earth's magnetosphere news from 2006 and earlier

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The Earth's Magnetosphere

Earth's Magnetosphere in the News: