Jupiter’s Great Red Spot is one of the most well-known features of the gas giant. At almost one and a half times the size of Earth, the storm has been known to exist since at least the 17th century when it was discovered by telescope.
Alas, time could be running out for Jupiter’s most distinctive feature. The storm has been decreasing in size for quite some time now; when Voyager I and II passed by in 1979, the Great Red Spot was twice the size of Earth. According to a NASA Jet Propulsion Laboratory report, the storm was measured to be shrinking at a rate of 930 kilometres per year in 2012.
The disappearing storm has recently gained media attention as there has been a potential 10 to 20-year timeline put on the storm’s further lifespan by Glenn Orton, planetary scientist at NASA Jet Propulsion Laboratory and Juno team member. The storm, which has outlasted many generations of life here on Earth, may be nearing its end.
Storms on Jupiter last a lot longer than storms here on Earth. On Earth, the longest lasting recorded storm was Hurricane John, lasting 31 days in total. The thicker atmosphere of Jupiter and its lack of solid land along with the planet’s faster spin and larger size allow storms to outlast those on Earth.
However, not all storms on Jupiter last as long as Jupiter’s Great Red Spot. In an article written by Business Insider, Ortin describes what makes the Great Red Spot Unique. “Think of the GRS [Great Red Spot] as a spinning wheel that keeps on spinning because it’s caught between two conveyor belts that are moving in opposite directions. The GRS is stable and long-lived because it’s ‘wedged’ between two jet streams that are moving in opposite directions.”
We currently have a close-up look at the storm as Juno, NASA’s space probe is orbiting Jupiter. The spacecraft was launched in 2011 and recently completed its tenth science flyby in early February 2018. The spacecraft has captured and sent back images as it works on its mission objectives which include studies of Jupiter’s magnetic field, gravitational field and determining water presence.
We will continue to have a front-row view of the storm until the Juno spacecraft is deorbited into Jupiter. Despite the storms currently shrinking size, nobody is really quite sure what lies ahead, including Ortin himself. What we do know is that the Great Red Spot is changing and here on Earth, scientists are watching intently, hoping to learn more about our Solar System’s largest planet.