Jupiter's Great Red Spot (GRS) is continuously shrinking as evidenced by images captured by the Hubble Space Telescope of the National Aeronautics and Space Administration (NASA). Experts said that the superstorm has deceased into its smallest size ever measured.
Amy Simon from the Goddard Space Flight Center in Maryland said that the images of the spot are now about 10,250 miles across, which is less than 50 percent of its historical size.
Experts have been observing the change in sizes of the spot since the 1930s. In 1800s, the storm was initially identified to have a size of approximately 25,500 miles across its long axis. In 1979, NASA Jupiter flybys, Voyager 1 and 2, observed another decrease in size as the spot measured only 14,500 miles across at that time. Through a Hubble capture, astronomers found yet another size downgrade in 1995, with the storm measuring about 13,020 miles across. Before the most recent observation, the spot was determined to have a measurement of 11,130 miles across in 2009.
Amateur monitoring starting in 2012 found that there is an apparent rise in the rate at which the storm is becoming smaller. As per estimates, the rate of decrease is about 580 miles per year. With this, the oval spot has also changed its shape to circle.
The largest planet in our solar system is mainly composed of gases, majority of which is hydrogen. Some helium and smaller levels of other gases, which project the makings of an early solar nebula, leading to a pleasant weather, may also be observed.
The clouds of Jupiter is one of the most spectacular sights of observation because it is composed of wide variety of colors such as red for ammonia, white for ammonium hydrosulphide and some blue and brown courtesy of water ice. The cloud systems rotate counterclockwise in belts and zones, moving in the east and west directions at approximately 100 meters per second.
With all the beauty that Jupiter possesses, its most noticeable feature remains to be the GRS. The spot twirls around the southern hemisphere of the planet and wrapping a massive 10 degrees of latitude.
GRS has been observed for about 350 years, with the first ever observation reported by Robert Hooke and Gian-Dominique Cassini between 1664 to1665.
Clearly, GRS is undergoing significant changes but the reason as to why this is happening remains to be a big question.
"In our new observations it is apparent very small eddies are feeding into the storm," said Simon. She added that their team thinks that these eddies may be the reasons behind the fast-paced modifications, as it alters the dynamics and energy of the GRS interior. They plan to conduct further investigations to identify if these eddies can feed or stop propulsions penetrating the upwelling vortex, causing the shrinkage.
In July 2016, NASA's Juno spacecraft will be reaching Jupiter and hopefully, this mission could unravel the mystery surrounding the GRS decline.