A horseman poses at Monument Valley Tribal Park in Utah August 14, 2012.
A rainbow arches over Hong Kong's Victoria Harbour June 19, 2012.
A river runs through a valley near Moose Pond, Northwest Territories August 21, 2012.
A long exposure shows stars behind a tree during the annual Perseid meteor shower near the southern town of Mitzpe Ramon August 13, 2012. REUTERS/Amir Cohen
A young man jumps in a fountain of the Trocadero to cool off, in front of the Eiffel tower in Paris, August 19, 2012 as an unusual heatwave continues to hit continental Europe. REUTERS/Vincent Kessler
A sailing boat is pictured on the Lake Leman during a warm autumn day in Chexbres October 5, 2012.
Swiss farmer Jean-Daniel Waber harvests his organic wheat field near Sullens, western Switzerland July 18, 2012. REUTERS/Denis Balibouse
A visitor walks in the Chamber of Stalactites and Stalagmites at the Nemocon salt mine in Colombia September 26, 2012. REUTERS/Jose Miguel Gomez
A tourist poses for a picture along the crater of the Cerro Negro volcano, one of the most active in Nicaragua, before volcano surfing down its slopes in Leon, about 120 kilometers (75 miles) northwest from Managua July 23, 2012. REUTERS/Oswaldo Rivas
An August 27, 2012 NASA handout photo shows a portion of the Grand Canyon.
A ferry crosses the Hudson River as the sun sets on One World Trade Center (C) and the skyline of Lower Manhattan in New York as seen from Hoboken, New Jersey, May 25, 2012.
Grape pickers cut bunches of grapes above Lake Leman during the first days of the harvest in the Lavaux region in Chexbres October 2, 2012. REUTERS/Denis Balibouse
A night view taken from the Muottas Muragl mountain, 2,546 metres (8,058 feet), shows the Swiss mountain resort of St. Moritz (top), and the village of Celerina (R), August 22, 2012.
The MSC Divina cruise ship is seen in Venice lagoon June 16, 2012.
A Maid of the Mist tourist boat is seen from the Canadian side of the Horseshoe Falls in Niagara Falls May 31, 2012. REUTERS/Mark Blinch
Lighting strikes over a barn surrounded by a soybean crop in Donnellson, Iowa, July 13, 2012.
Students from the University of Indonesia walk inside Jomblang cave at Gunungkidul district, near the ancient city of Yogyakarta June 20, 2012. REUTERS/Dwi Oblo
Residents dance at a square next to the Yangtze River in Badong city, 100km (62 miles) from the Three Gorges dam in Hubei province August 8, 2012. REUTERS/Carlos Barria
Swirls of green and red appear in an aurora over Whitehorse, Yukon on the night of September 3, 2012 in this NASA handout image. REUTERS/Courtesy of David Cartier, Sr./NASA/Handout
A penguin swims near Arpoador beach in Rio de Janeiro July 5, 2012.
People enjoy the Altausseer See (Altaussee lake) in the alpine village of Altaussee in Austria's southern province of Styria August 23, 2012. REUTERS/Herwig Prammer
A woman walks on the elevated skyway of the Supertrees Grove at the Gardens by the Bay in Singapore June 28, 2012. REUTERS/Tim Chong
Public and private residential blocks are seen on a hillside in Hong Kong June 19, 2012.
A pine tree is seen in a Taiga district near the town of Yeniseisk, 310 km north of Russia's Siberian city of Krasnoyarsk, May 27, 2012. REUTERS/Ilya Naymushin
The National Grand Theatre, nicknamed "The Egg", is seen on a sunny day in Beijing May 30, 2012.
An aerial view of Christ the Redeemer statue is lit up in green to celebrate the Rio 20 forum in Rio de Janeiro in this June 14, 2012 handout. REUTERS/Siemens/Handout
Stella Charmpa and Andrew Pimlott sit on the grass in Central Park in New York July 5, 2012.