NASA Lets Us Watch the Sun Spin For 3 Years In 4 Minute Video 34
An anonymous reader writes "Back in February 2010 NASA launched the Solar Dynamics Observatory–a 3-axis stabilized satellite and fully redundant spacecraft. The aim of the SDO is to monitor solar activity and see how that impacts space weather. As part of its observations, the SDO captures an image of the Sun every 12 seconds using the onboard Atmospheric Imaging Assembly, but varies those shots across 10 different wavelengths. NASA has now collected three years worth of image data from the SDO and has put together a video letting us see the Sun spin in all its glory."
If you watch closely, you can see individual frames containing the Moon and Venus.
FOSS Onboard SDO (Score:5, Informative)
The RTEMS Project (http://www.rtems.org) is very proud to be part of this successful mission. For details see http://rtemsramblings.blogspot.com/2010/02/nasa-solar-dynamic-observatory-launched.html [blogspot.com]
Re:Do they know why? (Score:5, Informative)
due to the sun's rotation, material at the equator weighs less than material at the poles. this drives a macro-level dual toroidal current from the poles to the equator internally, and from the equator to the poles externally. Just like on Earth, the flow of these currents are subject to Coriolis forces, resulting in lots of activity. As for the 11-year cycle, someone else will have to answer that.
Re:Do they know why? (Score:4, Informative)
The cause of the solar cycles is still under debate. One theory is tidal forces from Jupiter and to a lesser extent Saturn causes it, another is solar jet stream oscillations (which I think other replier below read about), another is the "solar inertial motion" of the Sun about the center of mass of the solar system.