The Northwest Passage, one that eluded famous explorers, may become a shipping lane because so much ice is melting in the Arctic. And now there's a race to see who will get rights to the melting area, where a U.S. study has suggested as much as 25 percent of the world's undiscovered oil and gas could be hidden.

Ice is now at its lowest level no record according to new satellite images and scientific research. The European Space Agency says nearly 200 satellite photos this month taken together showed an ice-free passage along northern Canada, Alaska and Greenland, and ice retreating to its lowest level since such images were first taken in 1978.

The waters are exposing unexplored resources, and vessels could trim thousands of miles from Europe to Asia by bypassing the Panama Canal. The seasonal ebb and flow of ice levels has already opened up a slim summer window for ships.

Leif Toudal Pedersen, of the Danish National Space Center, says Arctic ice has shrunk to some 1 million square miles. The previous low was 1.5 million square miles, in 2005.

"The strong reduction in just one year certainly raises flags that the ice (in summer) may disappear much sooner than expected," Pedersen said.

A U.N. panel on climate change has predicted that polar regions could be virtually free of ice by the summer of 2070 because of rising temperatures and sea ice decline, ESA noted.

Russia, Norway, Denmark, Canada and the United States are among countries in a race to secure rights to the Arctic that heated up last month when Russia sent two small submarines to plant its national flag under the North Pole.

Environmentalists fear increased maritime traffic and efforts to tap natural resources in the area could one day lead to oil spills and harm regional wildlife.