Bringing together 
imagery from many different satellites and astronaut missions, NASA's Earth Observatory publishes fantastic images with highly detailed descriptions, feature articles and more.Gathered here are some standout photographs from the collections in the Earth Observatory over the past years.
The East African volcano Nyiragongo accounts for 20 percent of all recorded eruptions in Africa. The volcano sits along the edge of the Western Rift, part of a giant crack in the Earth’s crust that runs for thousands of miles from the Middle East southward to central Africa. (IKONOS image ©2004 GeoEye)
The alpine lakes of the Tibetan Plateau are some of the most remote in the world. This mosaic of astronaut photographs, taken along a single International Space Station orbit track, depicts Lake Puma Yumco during the winter season. The lake is located at an elevation of 5,030 meters above sea level (16,503 feet), and is considered ultraoligotrophic, meaning that nutrient concentrations in both the water column and lake sediments are extremely low. The most striking feature of the image mosaic is the intricate ice block pattern on the lake surface. (NASA/JSC)
The Arabian Peninsula's Empty Quarter, known as Rub' al Khali, is the world's largest sand sea, holding about half as much sand as the Sahara Desert. The Empty Quarter covers 583,000 square kilometers (225,000 square miles), and stretches over parts of Saudi Arabia, Yemen, Oman, and the United Arab Emirates. The Enhanced Thematic Mapper on NASA's Landsat 7 satellite captured this image of the Empty Quarter on August 26, 2001. (NASA/Robert Simmon, Landsat,USGS)
The Dasht-e Kevir, or Great Salt Desert, is the largest desert in Iran. It is primarily uninhabited wasteland, composed of mud and salt marshes covered with crusts of salt that protect the meager moisture from completely evaporating. (NASA/Landsat)
Even the most snow-covered place on Earth has patches of snow-free ground. In Antarctica, a series of parallel valleys lie between the Ross Sea and the East Antarctic Ice Sheet. Known as the Dry Valleys, they are swept free of snow by nearly relentless katabatic winds - cold, dry air that rolls downhill toward the sea from the high altitudes of the ice sheet. The Dry Valleys harbor a collection of glaciers and ice-covered lakes. This false-color image was captured by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite on November 29, 2000. (NASA/Jesse Allen, NASA/GSFC/METI/ERSDAC/JAROS, U.S./Japan ASTER Science Team)
Cheju Island, alternately known as Chejudo or Jejudo, is an oval-shaped volcanic landmass covering 1,845 square kilometers (712 square miles) off the southern tip of the Korean Peninsula. Geologists estimate the island’s age at 2 million years, and archaeological finds suggest that people have lived on the island since prehistoric times. Today, Cheju is both a tourist attraction and home to a United Nations Educational, Scientific and Cultural Organization (UNESCO) World Heritage site. (NASA/Robert Simmon, Landsat,ETM+)
South of Khartoum, Sudan, where the White and Blue Nile Rivers join, a dizzying arrangement of irrigated fields stretches out across the state of El Gezira. The several bare-looking patches are small villages. This image was captured by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite on December 25, 2006. (NASA/GSFC/METI/ERSDAC/JAROS, U.S./Japan ASTER Science Team)
Deriba Caldera is a geologically young volcanic structure located at the top of the Marra Mountains of western Sudan. The Marra Mountains are part of a large geologic feature known as the Darfur Dome. The dome appears to be the result of a mantle plume, which is a fixed “hotspot” in the Earth’s mantle (the layer of Earth below the crust). The mantle plume heated the crust from below, leading to uplift of the crust and providing a magma source for the extensive volcanism observed in the region. The 5-kilometer-wide Deriba Caldera was formed by explosive eruption of the Jebel Marra Volcano approximately 3,500 years ago. The volcano is considered dormant, rather than extinct, as hot springs and fumaroles (gas and steam vents) are still present. (NASA-JSC)
This image, captured on January 21, 2005, shows just how close this two icy giants came to each other. At upper left is the tip of the Drygalski Ice Tongue, while at bottom is the northernmost portion of the B-15A iceberg. The distance between them was less than 5 kilometers on this day. (NASA/USGS)
Green circles in the desert frequently indicate tracts of agriculture supported by center-pivot irrigation. The Al Khufrah Oasis in southeastern Libya (near the Egyptian border) is one of Libya’s largest agricultural projects, and is an easy-to-recognize landmark for orbiting astronauts aboard the International Space Station. (NASA/JSC)
Cloudless skies allowed a clear view of Tibet in mid-December 2008. The Moderate Resolution Imaging Spectroradiometer (MODIS) flying onboard NASA's Terra satellite captured this true-color, image on December 18, 2008. Snow caps some mountain peaks, and ice partially covers some lakes in this high-altitude region, nicknamed the "Roof of the World." (NASA/Jeff Schmaltz, MODIS Rapid Response Team, Goddard Space Flight Center)
During the last ice age, Canada's Akimiski Island was buried under several thousand meters of ice, but since its retreat, the island has rebounded (risen in elevation) and new beach areas have emerged, streams and lakes have formed, and trees and other vegetation have colonized the new territory. This image of Akimiski Island was captured by the Landsat 7 satellite on August 9, 2000. (NASA/Jesse Allen, Landsat,University of Maryland's Global Land Cover Facility)
Houses and streets in bustling Las Vegas, Nevada are seen in this image from the commercial IKONOS satellite taken in September of 2004. (IKONOS image ©2004 GeoEye)
The Bear Glacier on the Kenai Peninsula along the Gulf of Alaska seen by the IKONOS satellite took this on August 8, 2005. This image shows the ablation zone where the glacier is primarily losing ice. Upslope from the lake, the foot of the glacier is riddled with crevasses - cracks in the ice caused by the glacier's movement over a rough surface. Down the middle of the glacier run dark gray stripes. As a glacier moves, it picks up dirt and debris from the rocks it passes. When two glaciers merge, as they have here, the dirt and debris they carry form parallel stripes, or medial moraines, on the ice surface. (IKONOS satellite image courtesy GeoEye)
Driven by powerful Santa Ana winds, wildfires raged near Los Angeles, California, in mid-October 2008. Not only did the winds fan the fires’ flames, they also sent the smoke far out to sea. (NASA-Aqua)
Harrat Khaybar in Saudi Arabia contains a wide range of volcanic rock types and spectacular landforms, several of which are represented in this photograph taken by an astronaut abourd the International Space Station on March 31, 2008. Jabal ("mountain" in Arabic) al Qidr is built from several generations of dark, fluid basalt lava flows. Jabal Abyad, in the center of the image, was formed from a more viscous, silica-rich lava classified as a rhyolite. (NASA-JSC)
This image of forest in the northern Republic of Congo was captured on June 27, 2002, by the commercial satellite Ikonos. Dirt logging roads (orange lines) cross the center of the image. This image is one of hundreds of satellite images from commercial and NASA satellites that scientists from the Woods Hole Research Center used to create a map of logging roads and forest disturbance across 4 million square kilometers of tropical African forests in the three decades proceeding 2003. (NASA /Jesse Allen, IKONOS, Nadine Laporte, Woods Hole Research Center)
The Southern Patagonian Icefield of Chile and Argentina hosts several spectacular glaciers, including this, the Grey Glacier located in the Torres del Paine National Park in Chile. It begins in the Patagonian Andes Mountains to the west and terminates in three distinct lobes into Grey Lake. (NASA/JSC)
Two cyclones are seen, after forming in tandem in November 2006. The Moderate Resolution Imaging Spectroradiometer (MODIS) onboard NASA's Terra satellite took this picture of the two cyclones south of Iceland on November 20 (South is up in image). (NASA/Jesse Allen, Earth Observatory)
A blue-green veil of water tumbles 51 meters over the rocky precipice of the Niagara Falls in this Ikonos image, acquired on August 2, 2004. Every second, more than two million liters of water plummets over the half-circle of the Canadian/Horseshoe portion of the Niagara Falls, shown here, making it one of the world’s largest waterfalls. (NASA/Ikonos)
