Jupiter moon Ganymede’s environment unique, says NASA

The magnetic field around Jupiter's moon Ganymede makes it unique in the solar system, according to a new NASA probe.

A newly analysed data from NASA's Galileo spacecraft's first flyby of the moon shows Ganymede as a moon like no other in the solar system owing to its magnetic field.

Ganymede is Jupiter’s largest moon in the Solar System and is the ninth largest object in the Solar System, without a substantial atmosphere. It is about 628.3 million km away from the earth.

NASA’s Galileo spacecraft has been spending eight years orbiting the Jupiter. The mission ended in 2003. The new revelation has been made based on the resurrected data from Galileo's first flyby of Ganymede, detailed in the journal Geophysical Research Letters.

"We are now coming back over 20 years later to take a new look at some of the data that was never published and finish the story," said study lead author Glyn Collinson from NASA's Goddard Space Flight Center in Greenbelt, Maryland.

In 1996, after arriving at Jupiter, Galileo found that Ganymede had its own magnetic field. While most planets in our solar system, including Earth, have magnetic environments -- known as magnetospheres -- no one expected a moon to have one.

Now, "we found there's a whole piece no one knew about," Collinson said. Between 1996 and 2000, Galileo made six targeted flybys of Ganymede, with multiple instruments collecting data on the moon's magnetosphere. The new results show fascinating facts about the magnetosphere's unique structure. 

(With inputs from agencies)