The "big red spot" is the big red spot(duh!) you can see in the southern hemisphere of Jupiter. It's a sort of a hurricane.
The spot was found in1664 by English scientist Robert Hooke.(you know, the guy who found the Hooke's law-the strain on a solid(e.g.a spring) is proportional to the applied stress) Since that time, it's always been there on Jupiter for more than 300 years. Talk about a bad day on Jupiter!
The vertical length of the spot hasn't changed much since the discovery of it, but in around 1876, the horizontal length of it was about twice that of now.
There was also a time when the color was a bit reddish, but now it has a lighter color.
Look at the size of that thing!it can fit an earth or two in it, I guess.
The spot moves around the planet, too. I had a hard time understanding this because, I thought the spot was unchanging and still. Well, the moment I saw this clip I swore that the spot moves. It's really beautiful. Taken by Voyager on its way to Jupiter.
It completes a whole turn around the planet every 6 days.