Tracking The Biggest Storm in Our Solar System

In 1665, Italian astronomer Giovanni Cassini peered through a telescope at Jupiter. It's our solar system's largest planet. He noticed its surface seemed speckled with swirling spots. He took notes about them. For centuries, experts assumed that the gas giant’s signature storm was among those observed by Cassini. It's the spot that appears like an unblinking, brick-red eye on the planet. New research, though, has raised questions about whether the storm existed when Cassini was alive.  

“We deduced that it is highly unlikely that the current Great Red Spot was the ‘Permanent Spot’ observed by Cassini,” lead study author Agustín Sánchez-Lavega said in a statement. He's a professor of physics at the University of the Basque Country in Spain. He noted that they arrived at that conclusion "from the measurements of sizes and movements."

According to NASA, Jupiter’s Great Red Spot is one of many cyclonic storms dotting its surface. The Great Red Spot is made up of ammonia, ice, sulfur, and phosphorus. It's 10,159 miles wide. That makes it equal in diameter to Earth. And it's more than 200 miles tall. It's also the largest storm on any planet in the solar system. With no land beneath it to slow it down, the storm whips along. Winds in the storm reach 280 miles per hour. 

The Great Red Spot is old by human standards. But Sánchez-Lavega’s research suggests it’s been around for a mere 190 years. It formed well after Cassini first glimpsed Jupiter almost 400 years ago. Sánchez-Lavega noted that the Spot is changing along a similar timeline to other storms on the planet. He has used supercomputers to study its shape and movement. The storm is shrinking. It's also rounding off and growing taller as it does so.      

Sánchez-Lavega believes it will disappear once it reaches a certain size, much as Cassini’s spots did hundreds of years ago.    

Reflect: What do you think are the most exciting aspects of exploring and studying other planets in our solar system?

Gif of Jupiter from GIPHY.