I love this graph.
It's from JUPOS, a crowd-sourced astronomy program to track atmospheric features on Jupiter. Specifically it's a graph of the width and center of the Great Red Spot since 2010, taken from observations from hundreds of astronomers. The project was started in 1975 by an East German astronomer. Over time they've collected historical data back to 1785 and built a network of observers using webcams (!) to take pictures of Jupiter. This graph is a quick view of a well known feature, they also track much more detailed numerical data about Jupiter's atmosphere.
  2012-12-30 16:41 Z