Scientists have found a Europe-sized cyclone lasting more than five years on Saturn, making it the longest-lasting cyclone detected to date on any of the giant planets of the Solar System.

Researchers from the University of the Basque Country, who started to track the cyclone in 2004, have been able to confirm its persistence until 2009. The cyclone is similar in size to the European continent.

Our observations make this cyclone the longest-lasting one ever seen on the giant planets of the Solar System, Jupiter and Saturn, said Teresa del Río-Gaztelurrutia, lead author of the study. We still know very little about these kinds of structures.

Another reason why it attracted our attention was its visual appearance, which is very reminiscent of the Great Dark Spot on Neptune, which – like the Great Red Spot on Jupiter – is an anticyclone, said Río-Gaztelurrutia.

The whirlwind is moving at 245 kilometers (153 miles) per hour, dragged by a strong jet stream, while the maximum speed of the winds around its edge is 72 kilometers per hour.

The scientists are waiting for the data from 2010 to find out how the disturbance has evolved over the past year. The latest data available are for 2009.