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Deep oranges and yellows appear in the troposphere, which extends from the Earth’s surface to 6–20 km high. This layer contains over 80 percent of the mass of the atmosphere and almost all of the water vapor, clouds, and precipitation. Several dark cloud layers are visible within this layer. Variations in the colors are due mainly to varying concentrations of either clouds or aerosols (airborne particles or droplets).
The pink to white region above the clouds appears to be the lower stratosphere; this atmospheric layer generally has few or no clouds, and it extends up to approximately 50 km above the Earth’s surface. Above the stratosphere, blue layers likely mark the transition between the middle and upper atmosphere as it gradually fades into the blackness of outer space.
The ISS was located over the southern Indian Ocean when this picture was taken, with the astronaut looking towards the west. Astronauts aboard the ISS see 16 sunrises and sunsets per day due to their high orbital velocity (greater than 28,000 km per hour). The multiple chances for photography are fortunate because at that speed, each sunrise or sunset only lasts a few seconds!
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While aurora are generally only visible close to the poles, severe magnetic storms impacting the Earth’s magnetic field can shift them towards the equator. This striking aurora image was taken during a geomagnetic storm that was most likely caused by a coronal mass ejection from the Sun on May 24, 2010. The ISS was located over the Southern Indian Ocean at an altitude of 350 kilometers (220 miles), with the astronaut observer most likely looking towards Antarctica (not visible) and the South Pole.
The aurora has a sinuous ribbon shape that separates into discrete spots near the lower right corner of the image. While the dominant coloration of the aurora is green, there are faint suggestions of red left of image center. Dense cloud cover is dimly visible below the aurora. The curvature of the Earth’s horizon (the limb) is clearly visible, as is the faint blue line of the upper atmosphere directly above it (at image top center). Several stars appear as bright pinpoints against the blackness of space at image top right.
Auroras happen when ions in the solar wind collide with atoms of oxygen and nitrogen in the upper atmosphere. The atoms are excited by these collisions, and they typically emit light as they return to their original energy level. The light creates the aurora that we see. The most commonly observed color of aurora is green, caused by light emitted by excited oxygen atoms at wavelengths centered at 0.558 micrometers, or millionths of a meter. (Visible light is reflected from healthy (green) plant leaves at approximately the same wavelength.) Red aurora are generated by light emitted at a longer wavelength (0.630 micrometers), and other colors such as blue and purple are also sometimes observed.
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Paramushir Island in the northern Kurils is an example of a large island built by several volcanoes over geologic time. This astronaut photograph shows the southern end of Paramushir Island after a snowfall. The western slopes of the mountains are brightly illuminated, while the eastern slopes are in shadow.
Four major volcanic centers create this part of the island. Fuss Peak (image center left) is an isolated stratovolcano connected to the main island via an isthmus. Fuss Peak last erupted in 1854.
The southern tip of the island is occupied by the Karpinsky Group of three volcanic centers. A minor eruption of ash following an earthquake occurred on this part of the island in 1952.
The Lomonosov Group to the northeast (image center) includes four cinder cones and a lava dome that produced several lava flows in the past, but there have been no eruptions from the Lomonosov Group in recorded history.
The most recent volcanic activity on Paramushir Island occurred in 2008 at the Chikurachki cone located along the northern coastline of the island at image top center. The summit of this volcano [1,816 meters (5,958 feet) above sea level] is the highest on Paramushir Island.
Much of the Sea of Okhotsk visible in the image is covered with low clouds that often form around the islands in the Kuril chain. The clouds are generated by moisture-laden air passing over the cool sea/ocean water, and they typically wrap around the volcanic islands.
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This detailed astronaut photograph was taken from the International Space Station (ISS) when it was located 400 kilometers (250 miles) to the northeast, but due to the long (800 mm) lens used, the photo includes detailed field patterns and city blocks. Green and brown fields show intensive agricultural activity in the area, and salt ponds are visible at the west end of the shallow Lake Aktashskoye at image center. The distance from the tip of the Cape to the largest local city, Lenine (population ~70,000, image lower left) is only 20 kilometers (12 miles).
Shcholkine, named for a Russian physicist, is a new town built in 1978 to house workers of the planned Crimean nuclear power plant. The partially completed plant was inspected following the Chernobyl disaster of 1986, and was found to be located on a site prone to earthquakes. Further construction was terminated, and the already built structures and construction equipment was abandoned in place. Today, Shcholkine is an increasingly popular tourist destination.
