Monday, December 20, 2010

SWARM of Satellites to Protect Earth from Radiation

December 16, 2010

ESA's SWARM constellation will give scientists a 3-D view of Earth's magnetic field to help shield us from high-energy particles which threaten living creatures and electronics.

Thursday, December 9, 2010

Sunday, December 5, 2010

Dark Jupiter May Haunt Edge of Solar System

The layout of the solar system, including the Oort Cloud, on a logarithmic scale. Credit: NASA

By Lisa Grossman
November 29, 2010

A century of comet data suggests a dark, Jupiter-sized object is lurking at the solar system’s outer edge and hurling chunks of ice and dust toward Earth.

“We’ve accumulated 10 years’ more data, double the comets we viewed to test this hypothesis,” said planetary scientist John Matese of the University of Louisiana at Lafayette. “Only now should we be able to falsify or verify that you could have a Jupiter-mass object out there.”

In 1999, Matese and colleague Daniel Whitmire suggested the sun has a hidden companion that boots icy bodies from the Oort Cloud, a spherical haze of comets at the solar system’s fringes, into the inner solar system where we can see them.

In a new analysis of observations dating back to 1898, Matese and Whitmire confirm their original idea: About 20 percent of the comets visible from Earth were sent by a dark, distant planet.

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Giant Stealth Planet May Explain Rain of Comets from Solar System's Edge

Diagram showing the position of the Oort Cloud. Credit: Southwest Research Institute

By Charles Q. Choi
December 1, 2010

Our sun may have a companion that disturbs comets from the edge of the solar system — a giant planet with up to four times the mass of Jupiter, researchers suggest.

A NASA space telescope launched last year may soon detect such a stealth companion to our sun, if it actually exists, in the distant icy realm of the comet-birthing Oort cloud, which surrounds our solar system with billions of icy objects.

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