Tracks of passing planes cut across the sky above Rattlesnake Lake near Seattle, Washington, while a stellar pinwheel whirls around the North Star.
Taken on August 7, this 4.5-hour time-exposure portrait captures the rotation of the Earth around its axis, creating a spectacular star trails effect.
Photograph byhisao mogi, National Geographic Your Shot
Astronaut Photography Reaches New Heights
High above the Earth, NASA astronaut Chris Cassidy enjoys the view—and the photography—aboard the International Space Station. Cassidy shot his photos from the 250-mile-high (400-kilometer-high) orbit of the space station.
Astronauts often say the time they cherish most aboard the orbiting lab is the time spent in the viewing cupola. It's easy to see why.
PHOTOGRAPH COURTESY OF NASA
Sand Dunes Crawl Across Mars
An infrared view of dark sand dunes on the floor of one of the oldest craters on Mars was captured by NASA's Mars Reconnaissance Orbiter on October 2.
Such raindrop-shaped sand dunes are made of grains of basalt (a volcanic rock) and are among the most widespread wind-formed features on the red planet.
PHOTOGRAPH COURTESY OF U. ARIZONA/JPL/NASA
Comet ISON Shines
A subtle sprinkling of snow fountained from the icy center of Comet ISON as it fell toward the sun, revealed in this enhanced image from NASA's Hubble Space Telescope.
The promised "comet of the century" disappointed sky-watchers with its too-close passage by our star, but the drama of the November solar flyby was entrancing.
Hubble recently looked for the remains of the icy visitor from the outer solar system and found nothing. But the reams of data, and images, from its death plunge will keep astronomers busy as they seek to increase their understanding of cometary compositions.
PHOTOGRAPH BY NASA/AP
Stars Burn Off Orion
Radiation from newborn stars heats up the Flame Nebula in the constellation Orion, some 1,300 light-years from Earth.
The resulting infrared light reached the European Space Agency's Herschel space telescope's sensitive instruments on April 18, and was colored white, yellow, and pink to create this image.
The star illuminating the Flame Nebula would appear as another dot on Orion's belt but for the huge cloud of dust obscuring it from view and making it appear four billion times dimmer.
Europe's largest river, the Danube spans 309,447 square miles (801,463 square kilometers) and winds its way through 19 countries.
Called the "Everglades of Europe," the Danube delta is home to more than 300 species of birds and 45 species of fish, according to NASA's Earth Observatory.
IMAGE COURTESY JESSE ALLEN AND ROBERT SIMMON, EO-1/NASA/USGS
Fomalhaut Catches Astronomers' Eyes
A star called Fomalhaut and its surrounding disk of debris have made astronomers sit up and take notice. That's because this picture, released January 8 by the Hubble Space Telescope, reveals that the debris field—made of ice, dust, and rocks—is wider than previously thought, spanning an area 14 to 20 billion miles (22.5 to 32 billion kilometers) around the star.
Scientists have also used the image to calculate the path of a planet, Fomalhaut b, as it makes its away around the star. It turns out that the planet's 2,000-year elliptical orbit takes it three times closer to Fomalhaut than previously thought, and its eccentric path could send it plowing through the rock and ice contained in the debris field.
The resulting collision, if it happens, could occur around the year 2032, suggests astronomer Paul Kalas of the University of California at Berkeley.
IMAGE COURTESY P. KALAS, U. CALIFORNIA, and ESA/NASA
India Makes Way for Mars
India's Mars Orbiter Mission blasted off on November 5, 2013, bound for a rendezvous with the red planet, a first effort from the subcontinent.
The $100 million Mangalyaan mission by the Indian Space Research Organization will send a refrigerator-size probe to orbit Mars and study the planet's thin atmosphere.
PHOTGRAPH BY PALLAVA BAGLA, CORBIS
Horsehead Nebula Celebrates Hubble Anniversary
This Hubble Space Telescope shot of the Horsehead Nebula, released April 19, was taken in celebration of the telescope's 23rd anniversary. Pictured in infrared wavelengths for the first time, the Horsehead is part of the larger constellation Orion.
Loops and arcs of glowing plasma trace the active regions' magnetic field lines, seen in the image. A massive cloud of energetic, charged particles, the CME smacked into the Earth's magnetosphere, triggering auroral displays.
PHOTOGRAPH COURTESY NASA SOLAR DYNAMICS OBSERVATORY
The vehicle provided ISS crew members with essential supplies, including oxygen, water, spare parts, even logistics equipment—2.9 tons of supplies in all. (See pictures of early U.S. spaceflight.)
PHOTOGRAPH COURTESY OF NASA
Northern Lights Over Norway
Late winter provides excellent opportunities to see the aurora borealis, known as the northern lights, in Norway.
As the Earth tipped into its vernal equinox on March 20, signaling the beginning of spring in the Northern Hemisphere, astronomy photographer Babak Tafreshi made this photograph while overlooking a fjord in the Norwegian Sea near Tromso.
The orange-red color can occur when the moon rises or sets, and is caused by moonlight refracting off particles of dust and pollution in Earth's atmosphere.
The next supermoon, which will occur on August 10, 2014, should appear similar to this year's sky show, since it will be 3.1 miles (5 kilometers) closer to Earth.
PHOTOGRAPH BY TAMAS LADANYI, TWAN
Curiosity Rover Takes Martian Selfie
In the year that "selfie" made it into the dictionary, NASA's Curiosity rover offered up its own self-portrait.
Made from dozens of exposures taken by the rover's Mars Hand Lens Imager (MAHLI), the self-portrait shows Curiosity near one of its favorite drilling targets, a rock called John Klein. The rover drove away from that site in May.
The rover's robotic arm is not visible in the mosaic because MAHLI resides on a turret at the end of the arm.
PHOTOGRAPH COURTESY NASA/AP
Spiral Galaxy Churns With Young Stars
Bursting with newborn stars, the spiral galaxy Messier 77 pinwheels in this Hubble Space Telescope image. Some 45 million light-years from Earth, the galaxy is thought to resemble our own Milky Way with its spinning arms.
The colors of the spiral in this image, released March 28, reveal where new stars form, shown here as red and blue highlighted areas. The overall glow indicates that the entire system burns with charged gas clouds.
PHOTOGRAPH COURTESY A. VAN DER HOEVEN and ESA/NASA
Spacewalk Repairs Plague Space Station
Flight engineers on the International Space Station, including U.S. astronaut Chris Cassidy (pictured), completed a 5.5-hour spacewalk on May 11 to repair a leaky coolant pump.
The pump provides ammonia coolant to systems on the ISS responsible for generating electricity for the station.
The leak was initially discovered on May 9 by Canadian astronaut Chris Hadfield, who reported seeing flakes coming off the ISS.
Astronauts were forced to undertake a similar series of dangerous spacewalks in December to repair the cooling system and replace a pump once more.
Shaped by Martian weather over great periods of time, the light ripples of coarse stones crisscross dark sand dunes. Here, they can be seen filling in the upper stretch of the Valles Marineris, the Grand Canyon of Mars.
PHOTOGRAPH COURTESY UNIVERSITY OF ARIZONA/NASA
Saturn's Rings Encircle Venus
Secure in Saturn's shadow, the Cassini spacecraft snapped this shot looking back toward the inner solar system. The picture captured a view of Venus, seen as the white dot among the rings.