In this video from NOVA’s Sun Lab, learn about the Sun’s ever-changing surface and magnetic field. Images and animations illustrate how the Sun’s magnetic field lines are affected by the motion of the Sun’s plasma. Over time, the magnetic field becomes twisted and more complex, which increases solar activity. When magnetic field loops break through the surface, relatively cool regions of plasma form sunspots. The crossing of magnetic field lines creates solar flares and coronal mass ejections. About every 11 years, the north and south magnetic poles exchange places, flipping the magnetic field and creating a regular cycle of high and low solar activity.
This video is available in both English and Spanish audio, along with corresponding closed captions.
The theory of how the Grand Canyon was formed is shown in this animation from NOVA, and features rare footage of a phenomenon known as debris flow.
In this video from NOVA’s Sun Lab, learn about the Sun’s composition and structure. The Sun is a plasma, primarily made of hydrogen with smaller amounts of other elements. Animations and images illustrate the physical and behavioral properties of the Sun’s six regions: the core, radiative zone, conv
In this video from NOVA’s Sun Lab, explore nuclear fusion and the balance of energy in the Sun. Intense heat and pressure in the Sun’s core cause protons to fuse together to form helium atoms, a process that releases large amounts of energy. This nuclear reaction—the same process that takes place in