The Great Red Spot has been a fixture of Jupiter 's cloudy visage for centuries and is among the most recognizable features in the solar system. But it won't always be there. In fact, the Great Red Spot is shrinking, and recently, news stories reported that it could vanish within the next 10 or 20 years . From a report: Older observations, from the late 1800s, suggest the storm once spanned more than 30 degrees in longitude and was more of a "Great Red Sausage," says Glenn Orton of NASA's Jet Propulsion Laboratory. But the storm's shape is changing, most significantly in width, and as time marches on it's becoming less oval and more circular. Way back when, the storm stretched more than 25,000 miles across. When the Voyager spacecraft flew by in the 1970s, scientists estimated that the Spot was just 14,500 miles wide. In 2014, a Hubble Space Telescope observation put the Spot at just 10,250 miles across, and by last spring, it spanned just 10,140 miles. So when will it disappear entirely? Truth is, scientists have no idea. But if you measure the rate at which the Great Red Spot has been shrinking, and extrapolate linearly from that, it looks like the spot will vanish completely in about 70 years, says Amy Simon of NASA's Goddard Space Flight Center. Problem is, "we know for certain it doesn't work like that at all," she says.