Space probe peers into gigantic storm

UNITED STATES: A Nasa spacecraft in orbit around Jupiter has begun transmitting data and images from humanity’s closest brush with the Great Red Spot, a flyby of the colossal crimson storm that has fascinated earthbound observers for hundreds of years.

The Juno space probe logged its close encounter with Jupiter’s most distinctive feature yesterday as it passed about 9000 kilometres above the clouds of the mammoth cyclone.

But it will take days for the readings captured by Juno’s array of cameras and other instruments to be delivered to scientists at the Jet Propulsion Laboratory (JPL) in Pasadena, California, and much longer still for the data to be analysed.

Scientists hope the exercise will help to unlock such mysteries as what forces are driving the storm, how long it has existed, how deeply it penetrates the planet’s lower atmosphere, and why it appears to be gradually dissipating.

Astronomers also believe a greater understanding of the Great Red Spot may yield clues to the structure, mechanics and formation of Jupiter as a whole.

‘‘This is a storm bigger than the entire Earth. It’s been there for hundreds of years. We want to know what makes it tick,’’ said Steve Levin, the lead project scientist for the Juno mission at JPL.

Levin said the storm was believed to be powered by energy oozing from Jupiter’s interior combined with the rotation of the planet, but the precise inner workings were unknown.

The Great Red Spot has been continuously monitored from Earth since about 1830, though observations believed to be of the same feature date back more than 350 years. The churning cyclone measures about 16,000km in diameter, with winds clocked at hundreds of kilometres an hour around its outer edges.

Once wide enough to swallow three Earth-sized planets, the famed weather system has been shrinking for the past 100 years and may eventually disappear. Still, it remains the most prominent characteristic of the solar system’s largest planet, a gargantuan ball of gas 11 times the diameter of Earth, with more than twice as much mass as all the other planets combined.

The encounter with the Great Red Spot was the latest of 12 flyby missions currently scheduled by Nasa for Juno, which is due to make its next close approach to Jupiter’s cloud tops on September 1. – Reuters

This enhanced-colour image of Jupiter’s Great Red Spot was created by citizen scientist Jason Major, using data from the Junocam imager on Nasa’s Juno space probe.