This storm shows no inclination of blowing itself out. Jupiter
's Great Red Spot was first observed by the Italian astronomer Giovanni Cassini in 1665; while observations were sporadic in the 18th and early 19th centuries, many astronomers think the storm has been roaring for the 345 years since it was first seen. The immense storm is the size of three Earths, and the winds reach speeds topping 400 miles per hour.
How has it kept churning through the centuries? Baker and Ratcliff explain that its energy comes from Jupiter's interior and smaller vortices. "Remarkably, Jupiter's interior supplies 70 percent more energy to the cloud tops than the planet receives from the Sun," they write. "Like a giant air compressor, gravitational contraction generates intense pressures and heat deep inside the planet. Powerful thunderstorms in Jupiter's atmosphere channel much of this heat to the cloud tops." Smaller storms are devoured by the Great Red Spot, which allows it to roar on.