Intro music.
In December 2004, NASA and the European Space Agency's SOlar and Heliospheric Observatory,
or SOHO, celebrated nine years of service in monitoring the Sun.
SOHO's studies include the Sun's hot interior, its visible surface, stormy atmosphere
and solar wind.
We study the Sun to better understand this dynamic star, because strong solar storms
can disrupt communications, damage satellites and harm astronauts in space.
Sunspot activity was very high in the fall of 2003, causing massive coronal mass ejections, or CMEs.
During these events, billions of tons of electrically charged particles
exploded from the Sun at speeds of more than 1,200 miles per second.
SOHO was able to transmit advance warning about these electromagnetic storms well ahead of their arrival.
With this information, astronauts orbiting in the International Space Station
were advised to move to a part of the Space Station for protection from possible exposure to electromagnetic radiation.
Originally designed to to observe the Sun's antics for about two years, SOHO has been so successful
that scientists are expecting to receive valuable data from the observatory until 2007.