Sun probe finds weaker solar wind
From Times Staff and Wire Reports
The solar wind -- a stream of charged particles ejected from the sun’s upper atmosphere at 1 million mph -- is significantly weaker, cooler and less dense than it has been in 50 years, according to new data from the solar probe Ulysses.
The cause seems to be a change in its magnetic flux, said Dave McComas of the Southwest Research Institute. Why it’s happening is a mystery, but it has fluctuated like this in the past.
Normally the sun goes through an 11-year cycle of more, then fewer, sunspots and a similar solar wind cycle.
But scientists said Tuesday that the sun is in “a very prolonged minimum.” Typically a solar minimum lasts about a year, but this low point began in the summer of 2006.
