Sunset from Space
The sun sets over western South America in this photo taken by an astronaut on the International Space Station (ISS). ISS astronauts see an average of 16 sunrises and sunsets during a 24-hour period. The diffuse line between night and day seen here is called the "terminator."
On the horizon, layers of Earth's atmosphere appear in colors ranging from bright white to deep blue.
River of Gold, In Blue
The meandering Ivalo River makes its way through northern Finland in this image made from data from the National Land Survey of Finland. The river, called Ivalojoki in Finnish, is also known as the "river of gold" thanks to a late-1800s gold rush that littered its banks with mining claims.
At the Top of the World
Where is this icy, rugged landscape? Take a guess and scroll down to see if you're right…
It's the roof of the world: Mount Everest and its surrounding peaks. A NASA astronaut snapped this picture from the International Space Station in January 2011, revealing the scale of the glaciers surrounding the world's highest peak. The tip-top of Everest is out of sight in this picture, located just off the bottom edge, but the northern summit approach to the mountain starts along the East Rongbuk Glacier in the top right of the photograph. The knife-edge pass in the center of the photograph is the North Col, where climbers ascend toward progressively higher camps along the way to the peak. Everest's summit is 29,029 feet (8,848 meters) above sea level.
These waves between Indonesia (top) and the coast of Australia (bottom) aren't caused by wind. They're a direct result of gravity.
The pattern is of atmospheric gravity waves playing on the surface of the ocean. Atmospheric gravity waves form when buoyancy pushes air up, and gravity pulls it back down. As the air descends in to the low point of the atmospheric wave, it touches the ocean surface, causing rough waters, visible here as long, dark vertical lines. The brighter regions show the crests of the atmospheric waves, because there, the water is calm and reflective.
Shadow of a Shuttle
Silhouetted against Earth's atmosphere, the Space Shuttle Endeavour cuts a striking figure in this 2010 photo taken from the International Space Station. The shuttle approaches the station against a backdrop of the layers of the atmosphere. The blue layer directly behind the shuttle is the mesosphere, and the white layer is the stratosphere. Below that is Earth's troposphere, the lowest portion of the atmosphere, seen in orange.
Where, oh where are these city lights brightening up the night? Here's a hint: This photograph was taken by an astronaut on the International Space Station who had a connection to the city below. Scroll down for an answer …
If you guessed Houston, home to NASA's Johnson Space Center and the training ground of astronauts, congratulations! In this photo taken by an Expedition 22 crew member in 2010, roughly 62 miles (100 kilometers) of the Houston metropolitan area are visible east to west. Houston is rotated from the view normally seen on maps, with Galveston Bay, southeast of the city, in the upper right of the photograph. Freeways radiate from the central downtown area, while suburban and residential urban land appears reddish-brown and gray-green, indicated lower light density and heavier tree cover. Along the Houston Ship Channel, petroleum refineries glow with dense golden-yellow light.
Astronauts Get Distorted View of Antarctica
Astronauts aboard the International Space Station snapped this image of Antarctica while over the South Atlantic Ocean on Oct. 4, 2011, about 1,1000 miles (1,800 kilometers) to the northeast. This long viewing distance, combined with the highly oblique angle, accentuates the shadowing of the ground and provides a sense of the topography similar to the view you get from an airplane. It also causes foreshortening of features in the image, making them appear closer to each other than they actually are.
While the bulk of the continent of Antarctica sits over the South Pole, the narrow Antarctic Peninsula extends like a finger towards the tip of South America. The northernmost part of the Peninsula is known as Graham Land, a small portion of which (located at approximately 64 degrees South latitude) is visible at the top left in this astronaut photograph.
Off the coast of Graham Land to the north-northwest, two of the South Shetland Islands—Livingston Island and Deception Island—are visible. Both have volcanic origins, and active volcanism at Deception Island has been recorded since 1800. (The last verified eruptive activity occurred in 1970.) Closer to the coastline of Graham Land, Brabant Island (not part of the South Shetlands) also includes numerous outcrops of volcanic rock, attesting to the complex tectonic history of the region.
Blowin' In the Wind
A plume of dust obscures part of the Red Sea in this satellite photo taken Dec. 12, 2011. The plume arose north of the city of Jeddah in Saudi Arabia, traveling southwest before stopping short of Sudan. The Red Sea is surrounded by dust-producing regions; it's also the site of gradual rifting that is tearing the African and Arabian plates apart.
Where the Trees Are
U.S. forests take center stage on this new map created by researchers at the Woods Hole Research Center, the U.S. Forest Service and the U.S. Geological Survey. The darker green the area, the denser and more robust the forest.
This inventory of woody biomass is important, because trees are one of the largest reservoirs for carbon on Earth &mash; they store carbon released by both natural and man-made processes. Understanding how much carbon trees store now is important for understanding how much they'll store in the future, and whether factors like where the trees are matter. Fine-scale maps like this one help with that effort, said Woods Hole researcher Josef Kellndorfer in a statement.
"We have to know how much we have, and where, in order to conduct sound management and harvesting," he said.
Capsized Costa Concordia
The Italian cruise liner Costa Concordia founders off the coast of Tuscany on Jan. 17 in this image captured by a satellite. The ship hit a rock and capsized on Jan. 13, triggering a hectic, poorly planned evacuation and a manslaughter charge for the captain, who was among the first to bail out from the sinking ship.