No, the space-based Solar Dynamics Observatory isn’t on the fritz—it was actually instructed to make this flip while snapping pics of the Sun. It might sound like NASA took this thing out for a joy ride, but there’s a very good reason for the evasive manoeuvre.
Since 2010, the SDO has been dutifully studying the sun, sending back some of the most stunning pictures we’ve ever seen of this flaming orb. Twice each year, NASA has the SDO perform a complete 360, and it does this to the help the probe’s Helioseismic and Magnetic Imager (HMI) instrument take precise measurements of the outer edge of the sun, known as the “solar limb,” as seen by the SDO.
Credits: NASA’s Goddard Space Flight Center/SDO/Joy Ng
Taking measurements with the HMI instrument is not without its challenges. The sun, with all its flares and stellar perturbations, is not a totally spherical object. This makes it tough for HMI to detect the sun’s outer perimeter when it’s perfectly still. The probe’s biannual spin allows each part of the camera to peer at the entire outer rim, allowing it to map the sun’s shape with greater accuracy.
The video shown above was taken in extreme ultraviolet wavelengths, a spectrum of light our eyes cannot detect. NASA colourised these wavelengths in gold, allowing us puny humans to view it. As the SDO performed its seven-hour manoeuvre, it took a photo once every 12 seconds. The resulting video makes it look the sun suddenly decided to perform a rather dramatic summersault. [NASA]