The Cassini spacecraft orbiting Saturn has sent high-resolution images, which includes those of a 'monstrous-giant storm,' which stayed alive for 200 days on the northern part of Saturn.

According to Space.com, the storm started out as small last year but had grown to encircle the entire planet by January 2011.

A Cassini imaging team member said that compared to Jupiter, which is known as a 'stormy planet', the giant storm seen on Saturn is unusual and has made them puzzled.

“This new storm is a completely different kind of beast compared to anything we saw on Saturn previously with Cassini, said Kunio Sayanagi, a space researcher, as he likened the Saturn storm to a volcano.

The fact that such outbursts are episodic and keep happening on Saturn every 20 to 30 years or so is telling us something deep about inside the planet, but we are yet to figure out what it is.”

Agrees Andrew Ingersoll, a Cassini imaging team member. The pressure builds up for many years before the storm erupts. The mystery is that there's no rock to resist the pressure - to delay the eruption for so many years.

The team hopes that as they extend the Saturn mission through to 2017, their puzzling questions would be answered.

Presently, the American National Aeronautics and Space Administration (NASA), the European Space Agency (ESA) and the Italian Space Agency (ASI) are working together on the Cassini-Huygens mission.

Check out Saturn's weather snapped by the unmanned Cassini spacecraft!