Neptune Still Springtime After All These Years

Neptune Still Springtime After All These Years



In the 1960s spring came to the southern hemisphere o Neptune,the Solar System's outermost gas giant planet.Of course, since Neptune orbits the Sun once every 16 earth-years,it's still springtime for southern Neptune, wher eachseason lasts over four decades Astronomershave found that in recent yearsNeptune has bee gettingbrighter, as illustrated inthis Hubble Space Telescope image made in 2002.Compare to Hubblepictures taken as early as 1996,the 2002 image shows a dramatic increase in reflectivewhite cloud bands in Neptune's southern hemisphere Neptune'sequator is tilted 29 degrees from the plane of its orbit,about the same as Earth's 23.5 degree tilt, an Neptune's weatherseems to be dramatically responding to thesimilar relative seasonal increase in sunlight -- even thoughsunlight is 900 timesless intense for the distant gas giant than for planet Earth.Meanwhile, summer is really just around thecorner, coming t Neptune's southern hemisphere in 2005.