Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
2001 September 24
Explanation: Our Sun is still very active. Last year, our Sun went though Solar Maximum, the time in its 11-year cycle where the most sunspots and explosive activities occur. Sunspots, the Solar Cycle, and solar prominences are all caused by the Sun's changing magnetic field. Pictured above is a solar prominence that erupted on May 15, throwing electrons and ions out into the Solar System. The image was taken in the ultraviolet light emitted by a specific type of ionized helium, a common element on the Sun. Particularly hot areas appear in white, while relatively cool areas appear in red. Our Sun should gradually quiet down until Solar Minimum occurs in 2007.
Authors & editors:
Jerry Bonnell (USRA)
NASA Technical Rep.: Jay Norris. Specific rights apply.
A service of: LHEA at NASA/ GSFC
& Michigan Tech. U.