... SUN MOON MERCURY VENUS MARS, JUPITER SATURN . ... News . ... solar system . ... Sun experiences seasonal changes, new research finds . ... The Sun undergoes a type of seasonal variability with its activity waxing and waning over the course of nearly two years, according to a new study by a team of researchers led by the National Center for Atmospheric Research (NCAR). ... The quasi-annual variations appear to be driven by changes in the bands of strong magnetic fields in each solar hemisphere. ...