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NARRATOR: Solar flares are unimaginably massive bursts of
white-hot, electrically charged gas fired by the sun thousands of
times a year. The most recent solar flares were among the biggest
ever recorded.
ANDREW COATES (Mullard Space Science Laboratory, England):
The sun itself is a thermonuclear furnace, and this flings off huge
amounts of dangerous material in very large explosions. In some
cases it's about the same mass as Mount Everest actually coming
towards us.
NARRATOR: As shown on PBS's NOVA, an invisible magnetic
shield protects the Earth from these space storms. But that shield
is getting weaker.
JOHN SHAW (Geologist, University of Liverpool, England):
The rate of change is higher over the last 300 years than it has
been for any time in the past 5,000. It's going from a strong field
down to a weak field, and it's doing it very quickly.
NARRATOR: Scientists think this means the magnetic field is
getting ready to reverse direction. When this happens, compasses
will point south instead of north, and animals with internal
compasses for navigation will have some adjusting to do. But while
the field is in transition, it will continue to get weaker, maybe by
as much as 90 percent.
ANDREW COATES (Mullard Space Science Laboratory, England):
This basically opens our defenses so that solar and galactic
radiation can hit the atmosphere directly. And this means that the
radiation at ground level increases as well.
NARRATOR: Leading to a slight increase in cancer deaths
worldwide as well as regular disruption of satellite communications.
At least we probably have a few hundred years to prepare for it, and
a drastically weakened shield does have a bright side. The natural
light shows called auroras, or northern lights, might start to
appear on a nightly basis—even in places they've never been
seen before. I'm Brad Kloza.
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