Envisat helps Polar Challenge racers on way to Magnetic North Pole   Team Polar Eyes, one of 16 teams racing in the Scott Dunn Polar Challenge to reach the Magnetic North Pole. Envisat ice maps are helping to ensure event safety.   This Envisat Advanced Synthetic Aperture Radar (ASAR) image was acquired in Alternating Polarisation mode where the bright areas represent smoother (younger) ice and the darker areas represent rougher (mainly multi-year) ice.   The Polar Challenge route covers 514 kilometres. Competitors begin with a four-day training expedition in which they ski from Resolute to Polaris Mine - the Polar Challenge starting point. The race itself runs from Polaris to Issachen Mine through three checkpoints. The first two checkpoints are resupply points where competitors rest for 12 to 24 hours and take on new food and fuel supplies, and the third is the 1996 position of the Magnetic North Pole. It is difficult for planes to land here so the finish line is 40 km after this point, near a disused airstrip.   Twin Otter aircraft and helicopters overfly the Scott Dunn Polar Challenge route in case of any problem - safety is the priority. Envisat-derived ice maps can help plan for emergency landing sites.   Envisat is a truly advanced Earth Observation satellite with a unique combination of sensors to vastly improve the range and accuracy of scientific measurements of the atmosphere, oceans, land surface and ice. Its total range of capabilities far exceeds those of any previous or planned Earth Observation satellite. Release date: 1 March 2012