Earth's magnetosphere and magnetic field lines, shaped by the solar wind

magnetosphere

(mag-nee -tŏ-sfeer) A region of space surrounding a planet within which charged particles are controlled by the magnetic field of the planet rather than by the Sun's magnetic field, which is carried by the solar wind (see interplanetary medium). The solar wind is the source of most of the charged particles, which form a tenuous gas known as a plasma. The region of a planet's magnetosphere is delimited by a boundary called the magnetopause and includes any radiation belts of the planet, such as the Van Allen belts of the Earth. The Earth's magnetosphere extends to 60 000 km on the sunward side of the planet but is drawn out by the solar wind into an elongated extension called a magnetotail stretching many times this distance on the side away from the Sun (see illustration). Magnetic reconnection of the magnetic field lines of the Sun and Earth occurs across the sunward surface of the magnetopause (at points where two lines are in opposing directions); reconnection allows energy and particles to be transferred to the magnetosphere from the solar wind. Above the magnetopause is a layer of turbulent magnetic field, the magnetosheath, enclosed by a shock wave where the smooth flow of solar-wind particles past the planet is first interrupted. Mercury, Jupiter, Saturn, Uranus, and Neptune are also known to possess magnetospheres. See also geospace.

Collins Dictionary of Astronomy © Market House Books Ltd, 2006

magnetosphere

[mag‚′nēd·ə‚sfir]

(geophysics)

The region of the earth in which the geomagnetic field plays a dominant part in controlling the physical processes that take place; it is usually considered to begin at an altitude of about 60 miles (100 kilometers) and to extend outward to a distant boundary that marks the beginning of interplanetary space.

magnetosphere

The magnetron produces oscillation because of the influence of a magnetic field on motion of electrons.

The upper part of the thermosphere where the earth's magnetic field plays a more important role in controlling the behavior of protons. Also called the protosphere

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References in periodicals archive

Specifically, it will look at the physics behind continuous interaction between particles in the solar wind and Earth's magnetosphere, the magnetic shield that protects the existence of life in our planet.

Airbus brings a SMILE to ESA; European-Chinese satellite will study the interaction between the solar wind and Earth's magnetosphere

They analyzed data from several satellites passing overhead during STEVE events in April 2008 and May 2016 to measure the electric and magnetic fields in Earth's magnetosphere at the time.

What Powers Celestial Phenomenon STEVE

Shiva Kavosi and Joachim "Jimmy" Raeder of the University of New Hampshire studied seven years of in situ data taken during NASA's Time History of Events and Macroscale Interactions during Substorms (THEMIS) mission, a constellation of five satellites launched in 2007 to study the magnetosphere. THEMIS crossed the magnetopause--the boundary between the magnetosphere and surrounding turbulent plasma--more than 1,000 times, supplying a much more useful database than did prior missions in this region of the atmosphere.

Kelvin-Helmholtz wave frequency in magnetosphere uncovered

A wide-field-of view imager in space takes astronomers a step closer towards global solar wind and magnetosphere imaging capabilities.

Lobster-Eye imager detects soft X-rays

At Earth, hot flow anomalies do not make it inside the magnetosphere, but they release so much energy just outside that the solar wind is deflected, and can be forced to move back toward the sun.

Venus being bombarded by planet-sized space weather explosions

Measurements show that the intensity built up right in the heart of the magnetosphere and only later spread to particles farther out.

Radiation belts powered locally

" The magnetosphere, which indicates the presence of a magnetic field, observed is localised in an area near the Gerasimovic crater, but there could be more such minimagnetospheres on the moon's surface," said Dr Anil Bhardwaj, head of planetary science at the Vikram Sarabhai Space Centre, Trivananthapuram, which had jointly conducted the experiment with the Swedish Institute of Space Physics.

Chandrayaan finds moon magnetic field

The attenuation of the solar magnetosphere and/or the Earth's magnetosphere allows more cosmic rays through the atmosphere from outer space with the consequence, according to Danish scientist Henrik Svensmark and his supporters, of producing (seeding) more clouds on Earth, which in turn will lead to a drop in temperature, and hence produce a cooling period, or possibly another Little Ice Age!

It's the sun, stupid! LETTERS

The craft also examined Mercury's magnetosphere, the vast magnetic bubble surrounding both the planet and exosphere.

Messages from Mercury

The energy of the charged particles in the magnetosphere also differs from that of 33 years ago, which could be a sign that the planet is highly sensitive to small changes in the sun's activity, he adds.

Mercury, as never seen before: MESSENGER visits innermost planet