Washington, Sep 6 (IANS): Using data from NASA's Cassini spacecraft, scientists have spotted a surprising feature emerging at Saturn's northern pole as it nears summertime -- a warming, high-altitude jet stream with a hexagonal shape.

The vortex is akin to the famous hexagon seen deeper down in Saturn's clouds, according to the finding published in the journal Nature Communications.

The results suggest that the lower-altitude hexagon may influence what happens above, and that it could be a towering structure hundreds of miles in height.

"The edges of this newly-found vortex appear to be hexagonal, precisely matching a famous and bizarre hexagonal cloud pattern we see deeper down in Saturn's atmosphere," said lead author of the new study Leigh Fletcher of the University of Leicester in Britain.

When Cassini arrived at the Saturnian system in 2004, the southern hemisphere was enjoying summertime, while the northern was in the midst of winter.

The spacecraft spied a broad, warm high-altitude vortex at Saturn's southern pole but none at the planet's northern pole.

The new study reports the first glimpses of a northern polar vortex forming high in the atmosphere, as Saturn's northern hemisphere approached summertime.

This warm vortex sits hundreds of miles above the Clouds, in the stratosphere, and reveals an unexpected surprise.

"The mystery and extent of the hexagon continue to grow, even after Cassini's 13 years in orbit around Saturn," Cassini project scientist Linda Spilker said.

"I look forward to seeing other new discoveries that remain to be found in the Cassini data," Spilker added.