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NASA's magnetosphere
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NASA's Wind Mission Encounters 'SLAMS' Waves

As Earth moves around the sun, it travels surrounded by a giant bubble created by its own magnetic fields, called the magnetosphere. As the magnetosphere ploughs through space, it sets up a standing bow wave or bow shock, much like that in front of a moving ship. Just in front of this bow wave lies a complex, turbulent system called the foreshock. Conditions in the foreshock change in response to solar particles streaming in from the sun, moving magnetic fields and a host of waves, some fast, some slow, sweeping through the region.
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Earth's magnetosphere behaves like a sieve

ESA's quartet of satellites studying Earth's magnetosphere, Cluster, has discovered that our protective magnetic bubble lets the solar wind in under a wider range of conditions than previously believed.
Earth's magnetic field is our planet's first line of defence against the bombardment of the solar wind. This stream of plasma is launched by the Sun and travels across the Solar System, carrying its own magnetic field with it.

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Origin of particle acceleration in cusps of Earth's magnetosphere uncovered

While flying through one of the cusps in Earth's magnetic field, the four spacecraft of ESA's Cluster mission have sampled the population of highly energetic particles that often fill these 'cavities'. A study of the data shows that particles are accelerated locally, within the cusps, as they cross regions characterised by different electric potential - a configuration that results from magnetic reconnection events. This is an important contribution to the long-standing debate concerning how and where these particles are accelerated.
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Mysterious electron acceleration explained

A mysterious phenomenon detected by space probes has finally been explained, thanks to a massive computer simulation that was able to precisely align with details of spacecraft observations. The finding could not only solve an astrophysical puzzle, but might also lead to a better ability to predict high-energy electron streams in space that could damage satellites.
Jan Egedal, an associate professor of physics at MIT and a researcher at the Plasma Science and Fusion Centre, working with MIT graduate student Ari Le and with William Daughton of the Los Alamos National Laboratory (LANL), report on this solution to the space conundrum in a paper published Feb. 26 in the journal Nature Physics.

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IBEX Spacecraft Finds Discoveries Close to Home

Travelling at a million miles per hour, the solar wind's protons and electrons sense Earth's magnetosphere too late to flow smoothly around it. Instead, they're shocked, heated, and slowed almost to a stop as they pile up along its outer boundary, the magnetopause, before getting diverted sideways.
Space physicists have had a general sense of these dynamic goings-on for decades. But it wasn't until the advent of the Interstellar Boundary Explorer or IBEX, a NASA spacecraft launched in October 2008, that they've been able to see what the human eye cannot: the first-ever images of this electromagnetic crash scene. They can now witness how some of the solar wind's charged particles are being neutralised by gas escaping from Earth's atmosphere.

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High-speed plasma jets: origin uncovered

For more than a decade, mysterious, high-speed plasma jets have been observed in space, downstream of the Earth's bow shock. The underlying formation mechanism for these jets has now been unveiled, thanks to data collected by the four ESA Cluster satellites. This study also suggests that such mechanisms may be relevant to other astrophysical shocks.
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Multiple rifts in Earth's magnetic shield

The Earth's magnetic field protects our planet from most of the permanent flow of particles from the solar wind. Fissures in this magnetic shield are known to occur, enabling the solar wind to penetrate our near-space environment. A study based on data collected by the four ESA Cluster satellites and the CNSA/ESA Double Star TC-1 spacecraft, provides new insight into the location and duration of these ruptures in the Earth's magnetic shield.
This study reports the observation of fissures on the Sun-facing side of the Earth's magnetic shield - the dayside magnetopause. Fortunately, these fissures don't expose Earth's surface to the solar wind; our atmosphere protects us, even when our magnetic field doesn't. However, clear effects have been detected high in the upper atmosphere and in the region of space around Earth where satellites orbit.

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U.S. researchers discover mystery about solar wind
U.S. researchers have for the first time discovered that the solar wind, a stream of energized particles that flows out from the sun, varies greatly in how it affects the earth's magnetosphere.
As a result of the discovery, spacecraft, power grids and other modern facets of life could be made safer, according to researchers at the University of California in Los Angeles (UCLA).


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Scientists have found that extreme solar activity drastically compresses the magnetosphere and modifies the composition of ions in near-Earth space. They are now looking to model how these changes affect orbiting satellites, including the GPS system.
The results were obtained from coordinated in-situ measurements performed by ESAs four Cluster satellites along with the two Chinese/ESA Double Star satellites.
Under normal solar conditions, GPS satellites orbit within the magnetosphere - the protective magnetic bubble carved out by Earths magnetic field. But when solar activity increases, the picture changes significantly: compressed and particles become energized, exposing satellites to higher doses of radiation that can perturb signal reception.

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