“Contrails (short for “condensation trails”) or vapour trails are artificial clouds that are the visible trails of condensed water vapour made by the exhaust of aircraft engines. As the hot exhaust gases cool in the surrounding air they may precipitate a cloud of microscopic water droplets or, if the air is cold enough, tiny ice crystals”. – Wikipedia

Photo: An airplane leaves a vapor trail as it flies in front of he moon on January 17, 2007 above Hanover, Germany. (Photo by Alexander Hassenstein/Getty Images)

Female Chimpanzee “Fifi” eats carrots as she sits in her enclosure at Taronga Zoo on her 60th birthday May 21, 2007 in Sydney, Australia. Fifi is the oldest of the Zoo's chimp population, which consists of 19 individuals. (Photo by Ian Waldie/Getty Images)

Mary McHugh mourns her slain fiance Sgt. James Regan at “Section 60” of the Arlington National Cemetery May 27, 2007. Regan, a US Army Ranger, was killed by an IED explosion in Iraq. (Photo by John Moore/Getty Images)

People walk past a downed tree in Central Park on October 31, 2011 in New York City. Central Park may lose 1,000 trees following a freak October snowstorm while the park only lost 125 trees due to Hurricane Irene. (Photo by Mario Tama/Getty Images)

Visitors attend a press preview of the 2012 Whitney Biennial at the Whitney Museum of American Art on February 27, 2012 in New York City. The contemporary art exhibition includes sculpture, photography, painting, installations, dance, theater, film and music and runs from March 1 through May 27. (Photo by Mario Tama/Getty Images)

Das Park Hotel was designed by Austrian architect and designer Andreas Strauss , and it is located in Linz, Austria. From inside, “rooms” have been humanized by Austrian artist Thomas Latzel Ochoa, who painted illustrations on walls. Hotel is open from May till October.

Russian pop art photographer Sergey Chilikov captures a nation liberated from the social oppression of late-era Soviet rule – at parties, in the streets, and bouncing high. His exhibition, Photoprovocations, will be at Photo London, 19-22 May. Here: Yoshkar-Ola, Matrosova Street (1995). (Photo by Sergey Chilikov)

“HA Schult, born Hans-Jürgen Schult on June 24, 1939 in Parchim, Mecklenburg is a German installation, happening and conceptual artist known primarily for his object and performance art and more specifically his work with garbage”. – Wikipedia

Photo: German artist Ha Schult stands with his “trash people” below the pyramids May 15, 2002 in Giza, Egypt. Inspired by the statues of the terracotta army of Chinese Emperor Quin Shi Huangdi (247–206 B.C.), the thousand piece sulpture has stood in Red Square in Moscow, La Defense in Paris and the Great Wall in China. Schult, born in 1939 wants to bring the “trash war” to the world's attention beause trash is the greatest battle facing mankind. (Photo by Norbert Schiller/Getty Images)