Neptune's Seasons
Springtime is blooming on Neptune! This might sound like an oxymoron because Neptune is the farthest and coldest of the major planets. But observations by NASA's Hubble Space Telescope reveal an increase in Neptune's brightness in the southern hemisphere. Astronomers consider this increase a harbinger of seasonal change. The observations, made over six years, show a distinct increase in the amount and brightness of the clouds encircling the planet's southern hemisphere.