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Blobrana


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40 year old Mariner 5 solar wind problem finds answer - turbulence doesnt go with the flow

Research led by astrophysicists at the University of Warwick has resolved a 40 year old problem with observations of turbulence in the solar wind first made by the probe Mariner Five. The research resolves an issue with what is by far the largest and most interesting natural turbulence lab accessible to researchers today.
Our current understanding tells us that turbulence in the solar wind should not be affected by the speed and direction of travel of that solar wind. However when the first space probes attempted to measure that turbulence they found their observations didn't quite match that physical law. The first such data to be analysed from Mariner 5 in 1971 found a small but nonetheless irritatingly clear pattern in the turbulence perpendicular to both the direction of the travel and the magnetic field the solar wind was travelling through.
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Blobrana


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Solar storms could create $2tn 'global Katrina', warns chief scientist

The threat of solar storms that could wreak havoc on the world's electronic systems must be taken more seriously, the UK government's chief scientist has warned. A severe solar storm could damage satellites and power grids around the world, he said, leading to a "global Katrina" costing the world's economies as much as $2tn (£1.2tn).
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Blobrana


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Bastille Day Flare
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The Bastille Day Flare or Bastille Day Event was a powerful solar flare on July 14, 2000 occurring near the peak of the solar maximum.  Active region 9077 produced an X5-class flare, which caused an S3 radiation storm on Earth fifteen minutes later as energetic protons bombarded the ionosphere

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Blobrana


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Solar research at RAL



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Blobrana


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Man-made aurora to help predict space weather

For more than twenty five years our understanding of terrestrial space weather has been partly based on incorrect assumptions about how nitrogen, the most abundant gas in our atmosphere, reacts when it collides with electrons produced by energetic ultraviolet sunlight and 'solar wind'.
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Blobrana


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Solar storms
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Spacecraft Reveals Small Solar Events Have Large Scale Effects

NASA's Solar Dynamics Observatory, or SDO, has allowed scientists for the first time to comprehensively view the dynamic nature of storms on the sun. Solar storms have been recognised as a cause of technological problems on Earth since the invention of the telegraph in the 19th century.
The Atmospheric Imaging Assembly (AIA), one of three instruments aboard SDO, allowed scientists to discover that even minor solar events are never truly small scale. Shortly after AIA opened its doors on March 30, scientists observed a large eruptive prominence on the sun's edge, followed by a filament eruption a third of the way across the star's disk from the eruption.
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Blobrana


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Shocking recipe for making killer electrons

Take a bunch of fast-moving electrons, place them in orbit and then hit them with the shock waves from a solar storm. What do you get? Killer electrons. That's the shocking recipe revealed by ESA's Cluster mission.
Killer electrons are highly energetic particles trapped in Earth's outer radiation belt, which extends from 12 000 km to 64 000 km above the planet's surface. During solar storms their number grows at least ten times and they can be dislodged, posing a threat to satellites. As the name suggests, killer electrons are energetic enough to penetrate satellite shielding and cause microscopic lightning strikes. If these electrical discharges take place in vital components, the satellite can be damaged or even rendered inoperable.
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Blobrana


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Coronal mass ejections
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New research has suggested that scientists can get warnings of impending ionised gas bursts, which are a potential threat to satellites and power grids, through clouds of plasma in space.
Till now, the arrival of burps of hot ionised gas from the Sun, has been hard to predict, but the first images of an earthbound burst captured by two satellites simultaneously have shown that plasma clouds can give warnings 24 hours in advance that trouble is heading our way.

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Blobrana


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Solar wind
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Solar flares are the most powerful explosions in the solar system. Packing a punch equal to a hundred million hydrogen bombs, they obliterate everything in their immediate vicinity. Not a single atom should remain intact.
At least thats how its supposed to work.

"Weve detected a stream of perfectly intact hydrogen atoms shooting out of an X-class solar flare. What a surprise! If we can understand how these atoms were produced, we'll be that much closer to understanding solar flares" - Richard Mewaldt of the California Institute of Technology.

The event occurred on Dec. 5, 2006. A large sunspot rounded the suns eastern limb and with little warning it exploded. On the "Richter scale" of flares, which ranks X1 as a big event, the blast registered X9, making it one of the strongest flares of the past 30 years.

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-- Edited by Blobrana at 20:34, 2008-12-15

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Blobrana


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Images from NASA-funded telescopes aboard a Japanese satellite have shed new light about the sun's magnetic field and the origins of solar wind, which disrupts power grids, satellites and communications on Earth.
Data from the Hinode satellite shows that magnetic waves play a critical role in driving the solar wind into space. The solar wind is a stream of electrically charged gas that is propelled away from the sun in all directions at speeds of almost 1 million miles per hour. Better understanding of the solar wind may lead to more accurate prediction of damaging radiation waves before they reach satellites. Findings by American-led international teams of researchers appear in the Dec. 7 issue of the journal Science.
How the solar wind is formed and powered has been the subject of debate for decades. Powerful magnetic Alfvén waves in the electrically charged gas near the sun have always been a leading candidate as a force in the formation of solar wind since Alfvén waves in principle can transfer energy from the sun's surface up through its atmosphere, or corona, into the solar wind.
In the solar atmosphere, Alfvén waves are created when convective motions and sound waves push magnetic fields around, or when dynamic processes create electrical currents that allow the magnetic fields to change shape or reconnect.

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