Using +Hubble Space Telescope observations from the past and including recent observations this year, astronomers have measured the diameter of Jupiter’s Great Red Spot at approximately 10,250 miles across, the smallest ever measured.

Astronomers have known that the giant storm feature on Jupiter has been shrinking since the 1930s, and now we have several decades of observations that show just how much and at what rate.

By comparison, the Great Red Spot was 14,500 miles across when NASA’s Voyager 1 and Voyager 2 spacecraft flew by Jupiter in 1979.

Starting in 2012, amateur observations revealed a noticeable increase in the spot’s shrinkage rate. The GRS’s “waistline” is getting smaller by 580 miles per year. The shape of the GRS has changed from an oval to a circle. The cause behind the shrinking has yet to be explained.

These new observations also show that very small eddies are feeding into the storm and my be responsible for the sudden change  by altering the dynamics and energy of the Great Red Spot.

Please join +Tony Darnell and +Carol Christian as they discuss these new observations with Dr. Amy Simon and others and bring your questions and comments.  We look forward to seeing you there!

Here is the link to the press release from last Thursday:
http://hubblesite.org/newscenter/archive/releases/2014/24/