Solar Winds Find Their Way Into Atmosphere
The Van Allen Belt is described by some as a magnetic shield,
standing between Earth and the harm it might be caused by magnetic
storms on the surface of the sun. But the shield is porous and
often, huge amounts of solar wind seep through, causing problems
for astronauts and their vehicles, aircraft on the move and even
powerplants on the ground.
Those findings came from scientists last week in the wake of the
biggest solar storm ever recorded. Published in the journal Nature,
lead researcher Harald Frey of the University of California's
Berkeley campus, says this new information "will help us to make
more accurate space weather predictions."
Another scientist who did not participate in the study, Janet
Kozyra of the University of Michigan, said, "It is critical for us
to understand where, when, and for how long the magnetic shield is
breached and how this energy gets in."
"We think we have solved an old and long-standing controversial
discussion of how this process of crack formation really works,"
said Frey. "Now that we know these cracks do not just open and
close sporadically ... but can stay open for a long and extended
time of several hours ... we can go on and incorporate this
knowledge into our next step of modeling space weather
The cracks in Earth's magnetic shield were first discovered by
the IMAGE satellite -- the Imager for Magnetopause to Aurora Global
Exploration. It tracked solar particles bombarding the Arctic. It
spotted an unusual aurora forming over the North Pole. At the same
time, the four satellites that make up the Cluster constellation
detected a crack in that magnetic shield.
"This aurora, energetic enough to power 75,000 homes, was
different from the visible aurora known as the Northern and
Southern lights," NASA said in a statement. While the aurora was
being recorded by IMAGE, the 4-satellite Cluster constellation flew
far above IMAGE, directly through the crack, and detected solar
wind ions streaming through. Normally, these solar wind ions would
be deflected by Earth's shield, so Cluster's observation showed a
crack was present."
In fact, such cracks are now known to be present all the time,
according to one Boston University researcher. The question now is,
how, with the new information available, will space and flight
operations deal with these cracks?