NASA Science News for March 2, 2011 -- The Sun's Great Conveyor Belt

  NASA Science News for March 2, 2011

When solar activity recently plunged into a century-class minimum, many
experts were puzzled. Now a group of researchers say they have cracked
the mystery of the missing sunspots.

FULL STORY at

http://science.nasa.gov/science-news/science-at-nasa/2011/02mar_spotlesssun/

Now they know. An answer is being published in the March 3rd edition of
Nature.


One thing is clear: During long minima, strange things happen. In
2008-2009, the sun’s global magnetic field weakened and the solar wind
subsided.  Cosmic rays normally held at bay by the sun’s windy magnetism
surged into the inner solar system.  During the deepest solar minimum in
a century, ironically, space became a more dangerous place to travel.
At the same time, the heating action of UV rays normally provided by
sunspots was absent, so Earth’s upper atmosphere began to cool and
collapse.  Space junk stopped decaying as rapidly as usual and started
accumulating in Earth orbit.  And so on….