... Tonight's Sky . ... SUN MOON MERCURY VENUS MARS, JUPITER SATURN . ... Video recaps Solar Dynamics Observatory's year four . ... Massive solar flares, graceful eruptions of solar material, and an enormous sunspot make up some of the imagery captured by NASA's Solar Dynamics Observatory during its fourth year in orbit. ... SDO's fourth year in orbit was no exception: NASA is releasing a movie of some of SDO's best sightings of the year, including massive solar explosions and giant sunspot shows. ...