Feb. 3 (UPI) -- A new mosaic provided by ESA's Mars Express probe has offered a comprehensive view of Mars' unique polar ice cap. As revealed by the new composite image, the permanent fixture of ice on Mars' north pole is marked by a swirl of deep troughs and canyons.
The mosaic is an amalgamation of 32 image surveys executed by Mars Express between 2004 and 2010. The surveys imaged a total of approximately 380,000 square miles.
The ice and troughs are carved by winds that blow from the polar apex outwards. The winds twist into a cyclone-like pattern by the Coriolis force, the same rotational force that explains the shape of hurricanes on Earth.
Scientists at the European Space Agency believe some of the cap's swirling trenches are older than the ice itself. Over time, they've become more dramatic as ice is pushed against their edges.
One of the polar canyons, Chasma Boreale -- perhaps the oldest in the region -- stretches 300 miles and bottoms out at a depth of 1.2 miles. The gutter nearly cuts the ice cap in half.
Mars Express was also to peer beneath the caps surface using radar, revealing historic layers of ice and dust as deep as 1.2 miles. Researchers say the subsurface images will help them reconstruct the history of Mars' shifting climate and axis tilt.