Artic Sea Ice Retreats

This map shows the extent of sea ice on September 17, 2008, measured by the Advanced Microwave Scanning Radiometer (AMSR-E) on NASA’s Aqua satellite.

The extent on September 17 was clearly much smaller than normal. Although this is not the first year the Northwest Passage has been navigable, it is the first year on record that both the Northwest Passage and the Northern Sea Route, on the opposite side of the Arctic, were both open.

For more information, go to NASA's Earth Observatory.