Jupiter's Great Red Spot is a massive storm that has been raging for at least 350 years.

The Great Red Spot is an anticyclonic storm located 22 degrees south of Jupiter's equator. While Giovanni Cassini is often credited with its 1665 discovery, modern astronomers use continuous records dating back to 1830 to track its evolution. Unlike Earth's hurricanes, which lose energy when they hit land, Jupiter lacks a solid surface. This absence of friction allows the storm to persist for centuries without dissipating.The storm is currently about 10,000 miles wide, which is roughly 1.3 times the diameter of Earth. However, historical data from the late 19th century suggests it was once much larger, spanning approximately 25,000 miles. NASA's Juno spacecraft, which arrived at Jupiter in 2016, has provided data showing the storm's roots extend about 200 miles deep into the planet's atmosphere.The Red Spot's crimson color remains a subject of scientific debate. Researchers at NASA's Jet Propulsion Laboratory suggest the hue results from solar UV rays interacting with ammonium hydrosulfide and ammonia in the upper atmosphere. This chemical reaction creates complex organic molecules called chromophores. Despite its longevity, recent observations from the Hubble Space Telescope show the storm is shrinking and becoming more circular over time.