Every eleven years, the sun's magnetic field flips. Sunspots—dark, cooler regions on the sun's surface that mark intense ...

Helioseismic data traces the solar dynamo to the tachocline about 200,000 km down.

When he wasn't designing warships, John Ericsson was dreaming up solar technology. The Swedish American inventor, credited with the screw propeller and the first ironclad vessel in the U.S. Navy, ...