The Great Red Spot is a gigantic cyclone swirling in the atmosphere on Jupiter. Winds whip at several hundred miles per hour inside the storm.
The spot was officially observed and measured in 1831 to be 25,000 miles across, large enough for three planet Earths to fit inside.
In 2014, the spot is only measuring one-third that size with only one Earth able to fit inside.
“What is happening? One possibility is that some unknown activity in the planet’s atmosphere may be draining energy and weakening the storm, causing it to shrink,” Hubble posted on its website.
Astronomers will host a live webcast on May 22 to talk about the shrinking Great Red Spot.