Earth’s magnetosphere tagged posts

The ERG spacecraft observed chorus waves and scattered electrons in the magnetosphere, the origin of pulsation auroras. The scattered electrons precipitated into the atmosphere resulting in auroral illumination. Intermittent occurrence of chorus waves and associated electron scattering lead to auroral pulsation. Credit: 2018 ERG science team.

For the first time, a satellite has directly observed the shower of electrons bouncing across Earth’s magnetosphere, allowing scientists to figure out what causes a rare form of Northern Lights known as pulsating auroras. Typically, the Aurora Borealis is caused by charged particles released from the upper atmosphere of the Sun...

In this simulation, a reconnection even pushes a blob of plasma toward Earth. The jet blown in the opposite direction wobbles due to the unstable conditions. Credit: NASA’s Goddard Space Flight Center/Yi-Hsin Liu/Joy Ng, producer

Every day, invisible magnetic explosions are happening around Earth, on the surface of the sun and across the universe. These explosions, known as magnetic reconnection, occur when magnetic field lines cross, releasing stored magnetic energy. Such explosions are a key way that clouds of charged particles – plasmas – are accelerated throughout the universe. In Earth’s magnetosphere – the giant magnetic bubble surrounding our planet — these magnetic reconnections can fling charged particles toward Earth, triggering auroras.

Magnetic reconnection, in addition to push...

The red ellipses show the MMS orbit paths during the first and second phases of the mission. Each spacecraft uses GPS signals – which come from satellites situated along the green circle shown surrounding Earth — from the far side of Earth to track its position. Credits: NASA/MMS

NASA’s Magnetospheric Multiscale mission, or MMS, is breaking records. MMS now holds the Guinness World Record for highest altitude fix of a GPS signal. Operating in a highly elliptical orbit around Earth, the MMS satellites set the record at 43,500 miles above the surface. The four MMS spacecraft incorporate GPS measurements into their precise tracking systems, which require extremely sensitive position and orbit calculations to guide tight flying formations.

Earlier this year, MMS achieved the closest flying s...

An illustration to explain the dynamics of the ultra-relativistic third Van Allen radiation belt, by Andy Kale. Credit: Andy Kale

Like a protective shield, the Earth’s magnetosphere absorbs and deflects plasma from the solar wind which originates from the Sun. When conditions are right, beautiful dancing auroral displays are generated. But when the solar wind is most violent, extreme space weather storms can create intense radiation in the Van Allen belts and drive electrical currents which can damage terrestrial electrical power grids. Earth could then be at risk for up to trillions of dollars of damage.

A new discovery shows for the first time how the puzzling third Van Allen radiation belt is created by a “space tsunami...