Here is one way to demonstrate concretely that STEREO is watching the Sun seven days a week, 24 hours a day. We have put together an entire week's (April 22- 28, 2007) worth of frames into a movie of the Sun in extreme ultraviolet light (304 Angstroms). The frames do not show off any major solar events. The devil, as they say, is in the details and what lovely details are revealed. The Sun's edge can be seen busily erupting with little spicules (vertical spikes), sliding plasma, small prominences loops, and fringe effects. These kinds of finely scaled events were much harder to pick out with SOHO. Why? Because SOHO's frames are only half as big and, thus, provide less resolution. And as for smooth motion, STEREO takes images in several wavelengths every 10 minutes, something that SOHO usually did in another wavelength, rarely in this one. So this is a visual treat that we can expect to see more and more of. Credit: NASA/STEREO/Naval Research Laboratory
