The following images were taken by astronauts on board the International Space Station. This Top 15 list was selected by NASA Johnson Space Center’s Earth Observations team.
1. Lake Chad and a Bodele Dust Plume, Sahara
Expedition 42: February 2, 2015
The arid landscapes of the Sahara and the darker vegetation of the wetter, semi-arid woodland known as the Sahel…
This east-looking image, taken by astronauts aboard the International Space Station, shows landscapes of the arid Sahara (image left) and the darker vegetation of the wetter semi-arid tropical woodland known as the Sahel (image right). The dark green marshes of Lake Chad stand out in the foreground of this view. Even though it is more than 200 km long, Lake Chad is the small remnant of a vast lake that has repeatedly occupied most of the region in this view in the recent geological past. This lake basin have stretches from the foreground almost 1000 km to the foot of the Tibesti Mountains (image top left). The lowest slopes of the Tibesti show the remnants of great deltas.
The image also captures an active dust plume—partly obscured by the so-called Canada Arm of the Space Station. The dust rises from the white mud flats of the ancient lake bed (image top left). Lofted into the atmosphere by northeasterly winds, dust from this basin often reaches the Atlantic Ocean, thousands of km to the west. Occasionally this dust is even carried by weather systems as far as the Americas.
2. Volcanoes, Vog, and Vortices, Hawaii
Expedition 42: February 8, 2015
Hawaii’s Kilauea volcano (image left) with the long swirls of volcanic gases (top half of the image) wafting west from the volcano…
3. Sierra Nevada de Santa Marta, northern Colombia
Expedition 42: February 27, 2015
A dramatic view of the many peaks of Colombia’s Santa Marta massif…
The highest of these (approximately 5700 m, 18,700 feet), named for Christopher Columbus, is so high that it supports a small but permanent snow cap (image far left), even though it lies only ten degrees north of the Equator.
4. Scandinavia at Night
Expedition 43: April 3, 2015
Southern Scandinavia just before midnight under a full moon…
Prominent features include a green aurora to the north (upper middle of the image), the blackness of the Baltic Sea (lower right), clouds (top right) and snow in Norway illuminated under a full moon.
5. Good Air and Brown Water, Argentina
Expedition 43: April 6, 2015
The eye-catching delta and green swamps of the Paraná River (image left) on the Atlantic coast of Argentina…
The Paraná River, South America’s second largest after the Amazon River, pours brown muddy water into a wide estuary known as the River Plate (image center and right).
6. Rivers and Snow in the Himalayas, China and India
Expedition 43: April 8, 2015
The Himalaya range, near the China–India border…. where peaks cast strong evening shadows on the snow…
For millions of years, water has eroded rock from these high mountains and deposited the sediment in ancient, broad alluvial fans. Snow cover highlights these strikingly smooth surfaces, while a trellis-like network of gullies cuts through and casts sinuous shadows.
7. Laguna Colorada, Bolivia
Expedition 43: April 16, 2015
The brightly colored Laguna Colorada, unique in this part of the Bolivian Andes Mountains…
The lack of atmospheric haze at great altitude—the lake lies at 4300 m above sea level (14,100 feet)—helps make images of the region especially clear. The strong red-brown color of this shallow, 10 km-long lake is derived from algae that thrive in its salty water.
8. Adele Island, northwest Australia
Expedition 44: June 11, 2015
A tiny island with many concentric zones around it. Adele Island, off Australia’s north coast…
The modern island is the dark central area, made up of a series of beach ridges built by sands from the surrounding sandbank during storms. The highest point is little more than 12 feet above sea level on this grassy but treeless island. A solar-powered lighthouse appears as a tiny white dot in the high-resolution image at the north tip of the island (arrowed).
9. Salt Ponds, western Australia
Expedition 44: June 11, 2015
Coastal lagoons with numerous rounded islands are typical of the Indian Ocean coastline of Western Australia…
These shapes contrast with the angular, white ponds of the salt extraction industry.
10. Shaping Cape Cod, Massachusetts
Expedition 44: June 13, 2015
The northern tip of Cape Cod—showing 8.5 miles (14 km) of its 65-mile (105 km) length…
In terms of geological age, Cape Cod is young, having been laid down about 20,000 years ago by glaciers when these were at their fullest extent. Even though Cape Cod today has water on both sides, it consists of moraine and associated river deposits laid down by two large lobes of ice that extended into the area from Canada (i.e, out of the image upper left). Strange as it seems today, one great ice lobe lay to the seaward side of the cape, and another on the Cape Cod Bay side.
11. The Port of Sfax, Tunisia
Expedition 44: June 19, 2015
The radiating street pattern of Tunisia’s second city and major port of Sfax (population ~900,000), that also hosts Tunisia’s largest fishing fleet (for scale the fishing port is 1.1 km long)…
More detailed visual cues that tell astronauts they are overflying Sfax are the brilliantly colored salt ponds south of the old city and the new circular earth works of the Taparura redevelopment project just north of the old city.
12. Flooding on the Mekong River floodplain, Thailand and Laos
Expedition 44: August 8, 2015
The Mekong River on the border between Thailand and Laos…
Southeast Asia’s largest river winds as a red-brown channel of floodwater resulting from very heavy monsoon rainfall that affected populations from North Vietnam through Thailand and Myanmar to India, starting on 26 July.
13. Red Sprites, northwest Mexico
Expedition 44: August 10, 2015
A red sprite above the white light of an active thunderstorm (image top left)…
Sprites are major electrical discharges, but they are not lightning in the usual sense. Instead, they are a cold plasma phenomenon without the extremely hot temperatures of lightning that we see underneath thunderstorms. e
14. Aquaculture, northeast China
Expedition 44: September 6, 2015
A grid pattern of fish farms on the coast of China’s northeast province of Liaoning…
The fish-farm basins have been built out from the dark-toned, wooded coast to a distance of nearly 6 km (4 mi)(image top left). Fish farms have been constructed at very many points along the province’s coastline, but this group of basins, facing the Yellow Sea, is the largest (Liaoning Province is the sixth in China in terms of aquaculture production).
15. India-Pakistan Border at Night
Expedition 45: September 23, 2015
Nighttime panorama looking north across Pakistan’s Indus River valley…
This photograph shows one of the few places on Earth where an international boundary can be seen at night. The winding border between Pakistan and India is lit by security lights that have a distinct orange tone. Another night image (click here) shows the border zone looking southeast from the Himalaya.
