Also found in: Encyclopedia, Wikipedia.


The outer boundary of a celestial body's magnetosphere.


the border between a magnetic field and the surrounding plasma, specifically that between the earth's magnetic field and the sun's plasma


(mægˈni təˌpɔz)

1. the boundary between the earth's magnetosphere and interplanetary space, ab. 40,000 mi. (65,000 km) above the earth.
2. a similar feature of another planet.
References in periodicals archive ?
The products can be used to evaluate the level of geomagnetic activity and the solar wind dynamic pressure, to estimate the magnetopause crossings and shocks, to provide input to the space weather forecasting model, to provide a database for improving knowledge of the magnetosphere and solar-terrestrial interactions, and last, but not least, to process the pitch-angle production after combination with the energetic electron data.
Along a radial cut of the plasma coming inward from the Sun near the dayside sub-solar point, the solar wind and magnetosheath flow is high-beta, the magnetopause and immediate (thin) plasma boundary provides a high to low beta transition, and immediately within the low-latitude boundary layer (within the outer magnetosphere) plasma is low-beta.
The magnetopause is located between 1000 and 2000 km from the planet's surface (on average at 1.
Once it reaches the outer magnetosphere, the author says, the plasma can be lost to the solar wind, either crossing through the magnetopause or being swept down the magnetotail.
The IMF meets up with Earth's magnetic field at the magnetopause, and it's here that a storm's power is determined.
In the study, a NASA satellite called IMAGE (Imager for Magnetopause to Aurora Global Exploration) observed two powerful proton auroras in the arctic portion of Earth's upper atmosphere, or ionosphere.
The magnetosphere's outer boundary is the magnetopause, a tear- shaped bubble marking the boundary between the region of influence of Earth's magnetic field and the region of influence of the Sun's magnetic field.
The researcher's statistical analysis showed that Kelvin-Helmholtz waves occur at the magnetopause about 19% of the time, which is "much more frequently than previously thought," notes Raeder.
Previous discoveries derived from Cluster measurements have shown that the magnetopause is commonly subject to Kelvin-Helmholtz waves.
In half an hour, this high-pressure wave travelled more than a million kilometres (620,000 miles) to the Earth's magnetopause.
They also identified the magnetospheric region that corresponds to these emissions, and by analogy with similar flares on Earth, they determine that the flares are probably related to pulsed reconnections of the magnetic field at the planet's dayside magnetopause (boundary where the planet's magnetic field meets the solar wind of particles flowing from the Sun).