The '
solar cycle' reflects magnetic
changes in our star, seen in the change of position as well as magnetic
polarity of sunspots. It was discovered and first described by German
astronomer
Samuel Heinrich Schwabe in 1843. This cycle waxes and
wanes every 11 (earth) years. The last solar cycle (cycle 23, by human count)
peaked in 2000-2002 then decayed to its low in 2008. A new cycle (solar cycle
24) began in that year. The 'solar maximum' is expected to occur sometime in 2012
(2013?).
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Samuel Heinrich Schwabe |
A '
solar maximum' implies increased solar magnetic activity
- more sunspot changes, more solar flares and possibly a '
solar storm'. To what
degree a solar storm affects our planet depends on the severity of the storm
itself as well as whether the storm on the sun takes place on an area that
directly faces the earth or at an angle, either resulting in a 'direct hit' of
our planet or simply a glancing blow.
In early 2012, a mild solar storm hit
our planet resulting in brilliant auroras at both poles - electromagnetic
radiation of a benign nature that showed us once again the beauty of nature
(see post:
Fire in the Sky).
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Solar Flares ('Storms') |
Solar storms launch energy into space in
three pulses: 1. electromagnetic radiation (much like an atmospheric nuclear
blast) that results in effects on the earth's magnetosphere causing remarkable
auroras and, in more extreme cases, warping or thinning of our protective
shield. 2. proton (ionizing) radiation from deeper inside the sun. Space-bound
astronauts, unprotected by our atmosphere may be at risk of exposure to these
'deadly rays'. 3. '
Coronal Mass Ejection' (CME) - expulsion of the sun's plasma
that strikes our planet.
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'Coronal Mass Ejection' (CME) |
These pulses can travel at speeds of up to 4 million miles
per hour. With the earth only 93 million miles from its star, that gives us
less than 25 minutes once a first pulse is launched!
In the year 2012, our planet was hit by severe
solar storms. During the week of March 5, 2012, the earth was witness to
increased solar 'rage'. But a big one? Has our lonely blue planet ever been
struck by a large CME? A direct hit? What happened?
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