A storm on Saturn

This beautiful image of Saturn taken by NASA’s Cassini probe shows us the magnificent planet and its latest and biggest storm:

From The Daily Galaxy:

Kunio Sayanagi, a Cassini imaging team associate and planetary scientist at UCLA: "This new storm is a completely different kind of beast compared to anything we saw on Saturn previously with Cassini. The fact that such outbursts are episodic and keep happening on Saturn every 20 to 30 years or so is telling us something about deep inside the planet, but we have yet to figure out what it is."

New images and animated movies from NASA's Cassini spacecraft chronicle the birth and evolution of the colossal storm that ravaged the northern face of Saturn for nearly a year.

These new full-color mosaics and animations show the storm from its emergence as a tiny spot in a single image almost one year ago, on Dec. 5, 2010, through its subsequent growth into a storm so large it completely encircled the planet by late January 2011.

The monster tempest, which extended north-south approximately 9,000 miles (15,000 kilometers), is the largest seen on Saturn in the past two decades and is the largest by far ever observed on the planet from an interplanetary spacecraft. On the same day that Cassini's high-resolution cameras captured the first images of the storm, Cassini's radio and plasma wave instrument detected the storm's electrical activity, revealing it to be a convective thunderstorm. The storm's active convecting phase ended in late June, but the turbulent clouds it created linger in the atmosphere today.

The storm's 200-day active period also makes it the longest-lasting planet-encircling storm ever seen on Saturn. The previous record holder was an outburst sighted in 1903, which lingered for 150 days. The large disturbance imaged 21 years ago by NASA's Hubble Space Telescope and comparable in size to the current storm lasted for only 55 days.

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"The Saturn storm is more like a volcano than a terrestrial weather system," said Andrew Ingersoll, a Cassini imaging team member at the California Institute of Technology in Pasadena. "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."