Stefan Dobrovolny of Austria and Inigo Munoz Elorza of Spain (R) stand in front of a quad bike during a simulated Mars mission on Tyrolean glaciers in Kaunertal, Austria, August 7, 2015. The Austrian Space Forum is sending some of its researchers to practice weight-less walking in spacesuits on a glacier which resembles the terrain on Mars. (Photo by Dominic Ebenbichler/Reuters)

Fishermen pull a net containing fish from a pond during the traditional carp haul near the village of Belcice, Czech Republic, October 25, 2016. Carp, the traditional Czech Christmas Eve dinner, is harvested primarly from the region of southern Bohemian lakes. (Photo by David W. Cerny/Reuters)

Dancers of the Friedrichstadt-Palast from the show “THE WYLD” pose during a promotional photocall in front of the Brandenburg Gate in Berlin, Germany, June 25, 2015. The 10.6 million euro ($13.5 million) show is the largest production budget in the 95-year history of Friedrichstadt-Palast. (Photo by Hannibal Hanschke/Reuters)

The National September 11 Memorial & Museum (branded as 9/11 Memorial and 9/11 Memorial Museum) is the principal memorial and museum commemorating the September 11 attacks of 2001, which killed nearly 3,000 people, and the World Trade Center bombing of 1993, which killed six. The memorial is located at the World Trade Center site, on the former location of the Twin Towers, which were destroyed during the attacks. The World Trade Center Memorial Foundation was renamed the National September 11 Memorial & Museum at the World Trade Center in 2007.

Every year, in the Rostov region of Russia, a group of 40 young and not so young rural workers compete in the Bison Track Show, or more affectionately known as: Russian Flying Tractor Racing. In front of crowds numbering up to 30,000 people, a series of smoke spilling, monstrous farming machines tear round an 8km mud track, plowing through lakes and dirt mounds, their turbos screaming and tyres scrabbling to find grip.

Amazing gravity-defying photo manipulations by Ravshaniya, a photographer from Uzbekistan, teeters on the edge of levitation. Photo: Untitled. (Photo by Ravshaniya)

Chamonix-Mont-Blanc or, more commonly, Chamonix is a commune in the Haute-Savoie département in the Rhône-Alpes region in south-eastern France. It was the site of the first Winter Olympics in 1924. The commune's population of around 9,800 ranks 865th within the country of France.