Full Disk View:
Image sequences taken April 8-9, 2007 by the EUVI telescopes on the two STEREO spacecraft (STEREO-B, left eye; STEREO-A, right eye). At this time the spacecraft were about 3.7 degrees apart. These images show the Sun in extreme ultraviolet light at a wavelength of 171 Ångströms, highlighting parts of the Sun's atmosphere (the corona) at about one million degrees C. Note the bright active regions near the Sun's equator and the dark "coronal holes" at the north and south poles. These are features of the Sun's magnetic field. Coronal holes are areas where the magnetic field opens out to allow material to flow out into the solar system, while active regions are made up of strong, closed fields which bottle up hot plasma (ionized gas) close to the surface. This image was taken near the minimum in solar activity, so there are few active regions.
Closeup View: Image sequences taken April 8-9, 2007 by the EUVI telescopes in the SECCHI imaging suites on the two STEREO spacecraft (STEREO-B, left eye; STEREO-A, right eye). At this time the spacecraft were about 3.7 degrees apart. Here we see a close up of solar magnetic active regions, flickering as they rotate out of sight around the sun. These are areas where the Sun's strong magnetic field bottles up million degree C plasma (ionized gas) low in the corona (the Sun's outer atmosphere). These images are taken at a wavelength of 171 Ångströms (0.00000171 cm) in the extreme ultraviolet.
Note for Large Displays: These movies are produced using images from STEREO where the angle between the spacecraft is getting larger than the optimum angle for stereo separation. While they work well on small displays, large-screens and projection systems can introduce significant distortions in the stereo effect which the audience may find uncomfortable. When doing large-screen projection, you may need to adjust the left-right image alignment for optimum viewing. However, this does not guarantee a distortion-free result.