Close to the globe, Earth's magnetic field wraps around the planet like a gigantic spherical web, curving in to touch Earth at the poles. But this isn't true as you get further from the planet. As you move to the high altitudes where satellites fly, nothing about that field is so simple. Instead, the large region enclosed by Earth's magnetic field, known as the magnetosphere, looks like a long, sideways jellyfish with its round bulb facing the sun and a long tail extending away from the sun.
In the center of that magnetic tail lies the plasma sheet. Here, strange things can happen. Magnetic field lines pull apart and come back together, creating explosions when they release energy. Disconnected bits of the tail called "plasmoids" get ejected into space at two million miles per hour. And legions of charged particles flow back toward Earth.
Such space weather events cause auroras and, when very strong, can produce radiation events that could cause our satellites to fail. But until now no one has been able to take pictures of these fascinating processes in the plasma sheet.
"Earth’s magnetic tail and its charged particles are invisible to conventional cameras that detect light,” says Jim Slavin, a magnetotail researcher who is the Director of the Heliophysics Division at NASA's Goddard Space Flight Center in Greenbelt, Md. "Events going on there have only been inferred based on other kinds of measurements."
Now, special cameras aboard the Interstellar Boundary Explorer, or IBEX, spacecraft have snapped the first shots of this complex space environment. Instead of recording light, these two large single-pixel cameras detect energetic neutral atoms. Such fast-moving atoms are formed whenever atoms in the furthest reaches of Earth's atmosphere collide with charged particles and get sent speeding off in a new direction. Called Energetic Neutral Atom or ENA imaging, the technique captured unprecedented images of the plasma sheet.
"The image alone is remarkable and would have made a great paper in and of itself because it's the first time we’ve imaged these important regions of the magnetosphere," says Dr. David McComas, principal investigator of the IBEX mission and assistant vice president of the Space Science and Engineering Division at Southwest Research Institute in San Antonio, Texas. The results appeared online in the Journal of Geophysical Research on Feb. 16, 2011.
But when they looked closely, the group realized they didn't only have a picture of a quiescent plasma sheet. The various images appear to show a piece of the plasma sheet being bitten off and ejected down the tail. They think they've caught a plasmoid in the moment it was being formed. If they're correct, this would be the first time such an event was directly seen.
"Imagine the magnetosphere as one of those balloons that people make animals out of. If you take your hands and squeeze the balloon, the pressure forces the air into another segment of the balloon," says McComas. "Similarly, the solar wind at times increases the pressure around the magnetosphere, resulting in a portion of the plasma sheet being pinched away from a larger mass and forced down the magnetotail."
Because researchers believe this phenomenon generally occurs deeper in the magnetotail, the IBEX team is considering other explanations for the event, as well. One possibility is that the plasma sheet is being squeezed by the solar wind.
While not specifically designed to observe the magnetosphere, IBEX's vantage point in space provides twice-yearly (spring and fall) seasons for viewing from outside the magnetosphere. Since its October 2008 launch, the IBEX science mission has flourished into multiple other research studies as well. In addition to supporting magnetospheric science, the spacecraft has also directly collected hydrogen and oxygen from the interstellar medium for the first time and produced the first ENA images of the outer edges of the bubble surrounding the Sun, called the heliosphere.
"Based upon the IBEX mission and its revolutionary ENA camera technology," says Slavin, "future NASA science missions may be able to make high definition videos of the development of space weather systems around the Earth to advance our scientific understanding of these phenomena and, eventually, enable space weather prediction like Earth weather prediction."
IBEX is the latest in NASA's series of low-cost, rapidly developed Small Explorers spacecraft. The Southwest Research Institute developed the IBEX mission with a team of national and international partners. Goddard manages the Explorers Program for the Science Mission Directorate in Washington.
For more information visit http://www.nasa.gov/mission_pages/ibex/news/spaceweather.html
- Fermi Telescope Caps First Year With Glimpse of Space-Time - November 8th, 2009 [November 8th, 2009]
- Antarctic Airborne Science Mission Nears Mid-Point - November 8th, 2009 [November 8th, 2009]
- NASA Awards Education Research Grants to Minority Universities - November 8th, 2009 [November 8th, 2009]
- New Celestial Map Gives Directions for GPS - November 8th, 2009 [November 8th, 2009]
- NASA Invites Reporters to Tranquility Node Ceremony at Kennedy - November 8th, 2009 [November 8th, 2009]
- Happy Halloween - November 8th, 2009 [November 8th, 2009]
- NASA's Fermi Telescope Detects Gamma-Ray From "Star Factories" in Other Galaxies - November 8th, 2009 [November 8th, 2009]
- NASA Announces Advisory Council Chairs and Committee Structure - November 8th, 2009 [November 8th, 2009]
- NASA and X Prize Announce Winners of Lunar Lander Challenge - November 8th, 2009 [November 8th, 2009]
- MESSENGER Spacecraft Reveals More Hidden Territory on Mercury - November 8th, 2009 [November 8th, 2009]
- Successful Flight Through Enceladus Plume - November 8th, 2009 [November 8th, 2009]
- Education Secretary Hosts DC Students for Talk with Space Station - November 8th, 2009 [November 8th, 2009]
- Operation Ice Bridge Studies Antarctic Sea Ice - November 8th, 2009 [November 8th, 2009]
- NASA West Point Welcomes Home One of Their Heroes - November 8th, 2009 [November 8th, 2009]
- NASA Spitzer Observes a Chaotic Planetary System - November 8th, 2009 [November 8th, 2009]
- X-38 Crew Return Vehicle Finds New Home - November 8th, 2009 [November 8th, 2009]
- Frost-Covered Phoenix Lander Seen in Winter Images - November 8th, 2009 [November 8th, 2009]
- Have some faith He is doing his best - November 8th, 2009 [November 8th, 2009]
- The Cross - November 8th, 2009 [November 8th, 2009]
- Spring Bloom in New Zealand Waters - November 8th, 2009 [November 8th, 2009]
- NASA Hubble image showcases star birth in M83, the Southern Pinwheel - November 8th, 2009 [November 8th, 2009]
- Take Me Out to the Ballpark - On Mars! - November 8th, 2009 [November 8th, 2009]
- Poisk Poised for Live NASA TV Space Station Docking - November 8th, 2009 [November 8th, 2009]
- Ceremony Reset for ESA Handover of Tranquility to NASA - November 8th, 2009 [November 8th, 2009]
- NASA Reproduces a Building Block of Life in Laboratory - November 8th, 2009 [November 8th, 2009]
- Now Online: Aeronautics Goes E-Book - December 12th, 2009 [December 12th, 2009]
- Water on the Moon, Drought on Earth: NASA Experts Available for Radio And Podcast Interviews During Major Science Meeting - December 12th, 2009 [December 12th, 2009]
- Launch of NASA's Wise Spacecraft Delayed Until Dec. 14 - December 12th, 2009 [December 12th, 2009]
- Connecticut Students Set for Cosmic Conversation with Space Station Commander - December 12th, 2009 [December 12th, 2009]
- Magnetic Dance of Titan and Saturn To Be Main Attraction during Flyby - December 12th, 2009 [December 12th, 2009]
- Hubble's Deepest View of Universe Unveils Never-Before-Seen Galaxies - December 13th, 2009 [December 13th, 2009]
- Earth's Moon - December 13th, 2009 [December 13th, 2009]
- How do you Make a Helicopter Safer to Fly? You Crash One. - December 13th, 2009 [December 13th, 2009]
- Physicist Earns Title as Kennedy's Best - December 13th, 2009 [December 13th, 2009]
- Hubble Unveils Never-Before-Seen Galaxies - December 13th, 2009 [December 13th, 2009]
- Saturn's Mysterious Hexagon Emerges from Winter Darkness - December 13th, 2009 [December 13th, 2009]
- Fermi Sees Brightest-Ever Blazar Flare - December 13th, 2009 [December 13th, 2009]
- Magnetic Power Revealed in Gamma-Ray Burst Jet - December 13th, 2009 [December 13th, 2009]
- Just 5 Questions: Aerosols - December 13th, 2009 [December 13th, 2009]
- Hometown Heroes 2009: Astronaut & Terrible Towel Return to Pittsburgh - December 13th, 2009 [December 13th, 2009]
- Garver Honors Four for Saving the Life of a Fifth at NASA Langley - December 13th, 2009 [December 13th, 2009]
- Administrator Bolden Speaks at AAIA-WIA Luncheon - December 13th, 2009 [December 13th, 2009]
- Best (Meteor) Shower of 2009 - No Towel Required - December 13th, 2009 [December 13th, 2009]
- NASA Making Government More Accessible With Cutting-Edge Use Of New Media - December 13th, 2009 [December 13th, 2009]
- Scarce Water, Our Quiet Sun and Space Rocks Among NASA News Highlights at American Geophysical Union Meeting - December 13th, 2009 [December 13th, 2009]
- Press Credentials Deadlines Set for Next Space Shuttle Flight - December 13th, 2009 [December 13th, 2009]
- Reddish Dust and Ice Migration Darken Saturn's Moon Iapetus - December 13th, 2009 [December 13th, 2009]
- Galaxy Collision Switches on Black Hole - December 13th, 2009 [December 13th, 2009]
- I’m watching the launch of NASA’s WISE spacecraft - December 13th, 2009 [December 13th, 2009]
- SOFIA Aloft - December 13th, 2009 [December 13th, 2009]
- Guide to the International Space Station Laboratory Racks Interactive - December 14th, 2009 [December 14th, 2009]
- Freezing WISE's Hydrogen - December 14th, 2009 [December 14th, 2009]
- Local High School Wins Invention Challenge - December 14th, 2009 [December 14th, 2009]
- WISE Ready to Soar Into Space - December 14th, 2009 [December 14th, 2009]
- NASA Data Reveal Major Groundwater Loss in California's Heartland - December 15th, 2009 [December 15th, 2009]
- NASA Looks for Safer Icing Forecast For Pilots - December 15th, 2009 [December 15th, 2009]
- Challenges of Living and Working Aboard the Space Station: NASA Astronaut Nicole Stott Available for TV Interviews - December 15th, 2009 [December 15th, 2009]
- NASA Astronaut, Food Scientist Available for Interviews about Holiday Feasts in Space - December 15th, 2009 [December 15th, 2009]
- NASA Launches Web Site for Teenagers That Want More Class - December 15th, 2009 [December 15th, 2009]
- A Unique Geography -- and Soot and Dust -- Conspire Against Himalayan Glaciers - December 15th, 2009 [December 15th, 2009]
- New Study Turns Up the Heat on Soot's Role in Himalayan Warming - December 15th, 2009 [December 15th, 2009]
- NASA's WISE Eye on the Universe Begins All-Sky Survey Mission - December 15th, 2009 [December 15th, 2009]
- NASA Offers Sound Clips for Radio, Online Newscasters - December 17th, 2009 [December 17th, 2009]
- NASA Gets Up-Close Look at Far Corner of the Globe - December 17th, 2009 [December 17th, 2009]
- Orion Launch Abort System Attitude Control Motor Test-fired - December 17th, 2009 [December 17th, 2009]
- Hubble Finds Smallest Kuiper Belt Object Ever Seen - December 17th, 2009 [December 17th, 2009]
- The Dark Side of Carbon - December 17th, 2009 [December 17th, 2009]
- R97UYEA6HD8W - December 17th, 2009 [December 17th, 2009]
- NASA's AIM Satellite and Models are Unlocking the Secrets of Mysterious "Night-Shining" Clouds - December 17th, 2009 [December 17th, 2009]
- Classroom Learning Takes Off with NASA-Funded Education Projects - December 17th, 2009 [December 17th, 2009]
- NASA Buys Additional Space Shuttle Reusable Solid Rocket Motors - December 17th, 2009 [December 17th, 2009]
- Searching for New Vaccines and Studying Butterflies in Space; NASA Offers TV Interviews about Latest Space Station Science Research - December 17th, 2009 [December 17th, 2009]
- NASA Partners with Saudi Arabia on Moon and Asteroid Research - December 17th, 2009 [December 17th, 2009]
- New Results from a Terra-ific Decade in Orbit - December 17th, 2009 [December 17th, 2009]
- Deposits in Martian Trough Point to Complex Hydrological Past - December 17th, 2009 [December 17th, 2009]
- NASA Outlines Recent Greenhouse Gas Research - December 17th, 2009 [December 17th, 2009]
- Unexpected Wheel-Test Results - December 17th, 2009 [December 17th, 2009]
- Solar Storms and Radiation Exposure on Commercial Flights - December 17th, 2009 [December 17th, 2009]
- Global Digital Elevation Model - December 17th, 2009 [December 17th, 2009]
- Hubble's Festive View of a Grand Star-Forming Region - December 17th, 2009 [December 17th, 2009]