The Great Red Spot of Jupiter SHRINKING ~ A storm that's been raging for over 300 years, it's three times the size of the entire Earth. NASA's recent Hubble Space Telescope observations confirm the Great Red Spot now is approximately 10,250 miles across, less than half the size of some historical measurements. Hubble's images over a span of decades show that the Great Red Spot is SHRINKING. NASA's Juno spacecraft is hurtling toward Jupiter now, due to reach the giant planet in July 2016…
Jupiter's Great Red Spot. The Great Red Spot is a great anti-cyclonic (high pressure) storm akin to a hurricane on Earth, but it is enormous (three Earths would fit within its boundaries) and it has persisted for at least the 400 years that humans have observed it through telescopes. Since it is anti-cyclonic in Jupiter's Southern hemisphere, the rotation is counterclockwise, with a period of about 6 days. (A hurricane in Earth's Southern hemisphere rotates clockwise.)
At about 89,000 miles in diameter, Jupiter could swallow 1,000 Earths. It is the largest planet in the solar system and perhaps the most majestic. Vibrant bands of clouds carried by winds that can exceed 400 mph continuously circle the planet's atmosphere. Such winds sustain spinning anticyclones like the Great Red Spot -- a raging storm three and a half times the size of Earth located in Jupiter’s southern hemisphere.
January 11 2017 : Crescent Jupiter with the Great Red Spot This image of a crescent Jupiter and the iconic Great Red Spot was created by a citizen scientist (Roman Tkachenko) using data from Juno's JunoCam instrument.