Imagine a storm of such size and scope to make the hurricanes of Earth seem tame. For centuries, the Great Red Spot on Jupiter has intrigued astronomers. The storm measures roughly 10,000 miles in width, and has raged for hundreds of years.
On July 10, NASA’s Juno spacecraft moved into position just a few thousand miles above the swirling clouds of the Great Red Spot, capturing stunning images of the counterclockwise circulation. Wind speeds within the storm can reach 400 mph, roughly double the highest hurricane winds here on Earth.
The red appearance of the Great Red Spot has long been a subject of debate. Clouds in the upper atmosphere of Jupiter contain ammonia, ammonium hydrosulfide, and water. But it is unclear if these compounds exist in sufficient quantity (or distribution) to produce such vibrant shades of red.
Such mysteries are being analyzed through the current Juno mission. The spacecraft launched on Aug. 5, 2011, and continues to provide a rich source of information for professional and amateur astronomers alike.