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NASA Celebrates 2012 Earth Day with Spectacular Satellite Images
The Lena River, some 2,800 miles long, is the easternmost of the three great Siberian rivers that flow into the Arctic Ocean and is one of the largest rivers in the world. The Lena Delta Wildlife Reserve, a protected wilderness area, provides an important refuge and breeding ground for many species of Siberian wildlife, and is also an important fish spawning site. NASA

On the occasion of the 42nd anniversary of Earth Day, NASA has compiled and released some of the most stunning and captivating images of earth.

From a glimpse of the Nile River Delta at night to a scenic view of the Northwest Greenland Canyons, the images showcase the earth in all its majesty.

NASA also is staging a series of activities and exhibits at the National Mall in Washington to mark the 2012 Earth Day. Additional activities are scheduled at nearby Nasa Goddard Space Flight Center in Greenbelt, Md.

At the National Mall, the "NASA Village" includes special exhibits and activities in three tents that highlight the use of the space agency's science and technology to advance knowledge and awareness of our home planet. Special activities include the weather versus climate game, a "Go Green" environment challenge, and Earth Science Pursuit.

NASA's Earth Science Division aims to study the earth's response to natural or human-induced changes, and to improve prediction of climate, weather, and natural hazards.

The theme for the current Earth Day celebrations is "Mobilize the Earth" wherein organisations and individuals across the globe will take part in activities to "demand" the protection of earth.

According to the Earth Day Network blog, an Earth Day Network partner in Taiwan, HIMA Foundation, is mobilizing through a massive tree planting event around New Taipei City. Bolivia is hosting a photography contest for Earth Day wherein, amateur photographers throughout the country will be encouraged to submit photographs of wildlife, biodiversity, and natural areas in need of conservation and protection.

In India, an Earth Day Network partner, Janhit Foundation, joined the campaign by organizing an inter-school debate competition across Meerut. Here, students will debate issues like water conservation and natural resource depletion and how they apply to India.

Start the slideshow to catch a glimpse of the spectacular earth images released by Nasa:

NASA India