Wednesday, September 24, 2008
Weaker Solar Wind Won't Slow Global Warming, May Threaten Astronauts
From Popular Mechanics:
If a spacecraft keeps chugging along for long enough, eventually it may find something startling.
Ulysses, a satellite operated by NASA and the European Space Agency, has been observing solar wind—charged particles ejected by the sun's upper atmosphere—since its launch in 1990. It's been around long enough to see two solar minimums, when the sun's radiation reaches the lowest point in an 11-year cycle, and a solar maximum, when the sun spouts sunspots and spews its highest level of radiation. But what Ulysses found during the most recent solar minimum has surprised astrophysicists: The solar wind was 20 to 25 percent weaker than during the last minimum, NASA and ESA announced at a press conference on Tuesday, and the weakest since they began measuring it at the dawn of the space age a half-century ago.
It's an exciting find for scientists studying the stars—a new weather condition adds a new variable in terms of research. But what does a weak solar wind really mean?
Read more ....