Tag Archives: radiation belts

Scientists solve a decades-old mystery in the Earth’s upper atmosphere

New research published in the journal Nature resolves decades of scientific controversy over the origin of the extremely energetic particles known as ultra-relativistic electrons in the Earth’s near-space environment and is likely to influence our understanding of planetary magnetospheres throughout the universe.

Discovering the processes that control the formation and ultimate loss of these electrons in the Van Allen radiation belts — the rings of highly charged particles that encircle the Earth at a range of about 1,000 to 50,000 kilometers above the planet’s surface — is a primary science objective of the recently launched NASA Van Allen Probes mission. Understanding these mechanisms has important practical applications, because the enormous amounts of radiation trapped within the belts can pose a significant hazard to satellites and spacecraft, as well astronauts performing activities outside a craft. (more…)

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UCLA scientists explain the formation of unusual ring of radiation in space

Since the discovery of the Van Allen radiation belts in 1958, space scientists have believed these belts encircling the Earth consist of two doughnut-shaped rings of highly charged particles — an inner ring of high-energy electrons and energetic positive ions and an outer ring of high-energy electrons.

In February of this year, a team of scientists reported the surprising discovery of a previously unknown third radiation ring — a narrow one that briefly appeared between the inner and outer rings in September 2012 and persisted for a month. (more…)

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How did a third radiation belt appear in the Earth’s upper atmosphere?

Since the discovery of the Van Allen radiation belts in in the Earth’s upper atmosphere in 1958, space scientists have believed that these belts consisted of two doughnut-shaped rings of highly charged particles — an inner ring of high-energy electrons and energetic positive ions, and an outer ring of high-energy electrons.

However, in February of this year, a team of scientists reported in the journal Science the surprising discovery of a previously unknown third radiation ring. This narrow ring had briefly circled the Earth between the inner and outer rings in September 2012 and then almost completely disappeared.

How did this temporary radiation belt appear and dissipate? (more…)

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‘Tis the Season — for Plasma Changes at Saturn

Researchers working with data from NASA’s Cassini spacecraft have discovered one way the bubble of charged particles around Saturn — known as the magnetosphere — changes with the planet’s seasons. The finding provides an important clue for solving a riddle about the planet’s naturally occurring radio signal. The results might also help scientists better understand variations in Earth’s magnetosphere and Van Allen radiation belts, which affect a variety of activities at Earth, ranging from space flight safety to satellite and cell phone communications.

The paper, just published in the Journal of Geophysical Research, is led by Tim Kennelly, an undergraduate physics and astronomy major at the University of Iowa, Iowa City, who is working with Cassini’s radio and plasma wave science team. (more…)

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Storm-chasing Spacecraft

A U-led experiment flies on a NASA mission to Earth’s radiation belts

The story goes that when Earth’s Van Allen Radiation Belts were first discovered, scientists were so amazed by the intensity of radiation, they thought they’d stumbled onto a Soviet nuclear test.

But they soon discovered that Earth is girdled by two concentric, doughnut-shaped regions of space, churning with radiation from protons, electrons, and other charged subatomic particles trapped in Earth’s magnetic field. (more…)

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