English: These Hubble Space Telescope images reveal an increase in Neptune's brightness in the southern hemisphere, indicating a seasonal change.

Observations of Neptune made over six years -- in 1996, 1998, and 2002 -- by a group of scientists from the University of Wisconsin-Madison and NASA's Jet Propulsion Laboratory (JPL) show a distinct increase in the amount and brightness of the banded cloud features located mostly in the planet's southern hemisphere.

Neptune, the eighth planet from the Sun, is known for its weird and violent weather. It has massive storm systems and ferocious winds that sometimes gust to 900 miles per hour, but these Hubble observations were the first to suggest that the planet undergoes a change of seasons.

Like Earth, Neptune would have four seasons. Unlike Earth, however, the seasons of Neptune last for decades, not months.

For more information, visit: hubblesite.org/news_release/news/2003-17

Credit: NASA, L. Sromovsky, and P. Fry (University of Wisconsin-Madison)