1 of 16 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 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 High above the African continent, tall, dense cumulonimbus clouds, meaning 'column rain' in Latin, are the result of atmospheric instability. The clouds can form alone, in clusters, or along a cold front in a squall line. The high energy of these storms is associated with heavy precipitation, lightning, high wind speeds and tornadoes. NASA This other worldly landscape is actually Dagze Co, one of many inland lakes in Tibet. In glacial times, the region was considerably wetter, and lakes were correspondingly much larger, as evidenced by the numerous fossil shorelines that circle the lake and attest to the presence of a previously larger, deeper lake. Over millennia changes in climate have resulted in greater aridity of the Tibetan Plateau. NASA/GSFC/METI/ERSDAC/JAROS, a As the shuttle and the space station began their post-undocking relative separation, Expedition 23 flight engineer Soichi Noguchi photographed the underside of the shuttle over the south end of Isla de Providencia, about 150 miles off the coast of Nicaragua. Undocking of the two spacecraft occurred on April 17, 2010, ending the shuttle's 10-day stay. The visit included three spacewalks and delivery of more than seven tons of equipment and supplies to the station. NASA Cloudless skies allowed a clear view of dust and hydrogen sulfide plumes along the coast of Namibia in early August 2010. The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite captured this natural-color image on Aug. 10, 2010. Multiple dust plumes blow off the coast toward the ocean, most or all of them probably arising from streambeds. Unlike the reddish-tan sands comprising the dunes directly south of the Kuiseb River, the stream-channel sediments are lighter in color. Wind frequently pushes dust plumes seaward along the Namibian Coast. Easterly trade winds blow from the Indian Ocean over the African continent, losing much of their moisture as they go. The winds are hot and dry as they pass over Namibia’s coastal plain, where they are prone to stir fine sediments. Even with dust plumes overhead, the marked change in land cover is obvious along the Kuiseb River. South of the river, sand dunes predominate, but the vegetation along the Kuiseb River prevents the dunes from advancing northward. North of the river, the land surface consists primarily of gravel plains punctuated by rocky hills. Hydrogen sulfide appears as a swath of irridescent green running parallel to the coast north of Walvis Bay. A 2009 study linked the emissions in this region to ocean currents, biological activity in the water column, and carbon-rich organic sediments under the water column. The meeting of hydrogen sulfide gas and oxygen-rich surface waters causes pure sulfur to precipitate into the water. The sulfur’s yellow color makes the water appear green to the satellite sensor. NASA The current Geostationary Operational Environmental Satellite GOES-13 captured this image of Hurricane Danielle heading for the north Atlantic. NASA/NOAA GOES Project The Ouachita Mountains in southeastern Oklahoma are part of the only major mountain region between the Rockies and the Appalachians. NASA/GSFC/METI/ERSDAC/JAROS, Off the coast of Argentina, two strong ocean currents recently stirred up a colorful brew of floating nutrients and microscopic plant life just in time for the Southern Hemisphere's summer solstice. The Moderate Resolution Imaging Spectroradiometer on NASA’s Aqua satellite captured this image of a massive phytoplankton bloom off of the Atlantic coast of Patagonia on Dec. 21, 2010. Scientists used seven separate spectral bands to highlight the differences in the plankton communities across this swath of ocean. NASA The Tien Shan mountain range is one of the largest continuous mountain ranges in the world, extending approximately 1,550 miles (2,500 kilometers) roughly east-west across Central Asia. This image taken by the Expedition 27 crew aboard the International Space Station provides a view of the central Tien Shan, about 40 miles (64 kilometers) east of where the borders of China, Kyrgyzstan, and Kazakhstan meet. NASA On March 29, 2011, Operation IceBridge flew between deep canyons and over glaciers along the northwest coast of Greenland. IceBridge, now in its third year, makes annual campaigns in the Arctic and Antarctic where science flights monitor glaciers, ice sheets and sea ice. NASA/Michael Studinger The relatively placid view from the International Space Station belied the potent forces at work in Hurricane Earl as it hovered northeast of Puerto Rico on Aug. 30, 2010. With maximum sustained winds of 135 miles (215 kilometers) per hour, the storm was classified as a category 4 on the Saffir-Simpson hurricane scale as it passed north of the Virgin Islands. NASA One of the fascinating aspects of viewing Earth at night is how well the lights show the distribution of people. In this view of Egypt, the population is shown to be almost completely concentrated along the Nile Valley, just a small percentage of the country’s land area. The Nile River and its delta look like a brilliant, long-stemmed flower in this photograph of the southeastern Mediterranean Sea, as seen from the International Space Station. The Cairo metropolitan area forms a particularly bright base of the flower. The smaller cities and towns within the Nile Delta tend to be hard to see amidst the dense agricultural vegetation during the day. However, these settled areas and the connecting roads between them become clearly visible at night. Likewise, urbanized regions and infrastructure along the Nile River becomes apparent. Scattered blue-grey clouds cover the Mediterranean Sea and the Sinai, while much of northeastern Africa is cloud-free. The thin yellow-brown band tracing the Earth’s curvature at the top of the image is airglow, a faint band of light emission that results from the interaction of atmospheric atoms and molecules with solar radiation at an altitude of approximately 60 miles (100 kilometers). NASA Like rivers of liquid water, glaciers flow downhill, with tributaries joining to form larger rivers. But where water rushes, ice crawls. As a result, glaciers gather dust and dirt, and bear long-lasting evidence of past movements. Alaska's Susitna Glacier revealed some of its long, grinding journey when the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA’s Terra satellite passed overhead on Aug. 27, 2009. This satellite image combines infrared, red and green wavelengths to form a false-color image. Vegetation is red and the glacier's surface is marbled with dirt-free blue ice and dirt-coated brown ice. Infusions of relatively clean ice push in from tributaries in the north. The glacier surface appears especially complex near the center of the image, where a tributary has pushed the ice in the main glacier slightly southward. Susitna flows over a seismically active area. In fact, a 7.9-magnitude quake struck the region in November 2002, along a previously unknown fault. Geologists surmised that earthquakes had created the steep cliffs and slopes in the glacier surface, but in fact most of the jumble is the result of surges in tributary glaciers. Glacier surges--typically short-lived events where a glacier moves many times its normal rate--can occur when melt water accumulates at the base and lubricates the flow. This water may be supplied by meltwater lakes that accumulate on top of the glacier; some are visible in the lower left corner of this image. The underlying bedrock can also contribute to glacier surges, with soft, easily deformed rock leading to more frequent surges. NASA/GSFC/METI/ERSDAC/JAROS, a Viewed from space, the most striking feature of our planet is the water. In both liquid and frozen form, it covers 75% of the Earth’s surface. It fills the sky with clouds. Water is practically everywhere on Earth, from inside the planet's rocky crust to inside the cells of the human body. NASA This unusual image was photographed through the Cupola on the International Space Station by one of the Expedition 30 crew members. The lake just above the bracket-mounted camera at center is Egirdir Golu in Turkey, located at 38.05 degrees north latitude and 30.89 degrees east longitude. A Russian Soyuz spacecraft is docked to the station at lower right and part of the Permanent Multipurpose Module (PMM) can be seen just above it NASA A new study has revealed that earth took ten million years to recover from mass extinction that took place 250 million years ago. 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: