NASA says it could be another 20 years before humans touch down on Mars, but in a sense, the Mars Society has been exploring the red planet for more than a decade – in Utah. Photo: Csilla Orgel, a geologist of Crew 125 EuroMoonMars B mission, makes her way back to the Mars Desert Research Station (MDRS) in the Utah desert March 3, 2013. The MDRS aims to investigate the feasibility of a human exploration of Mars and uses the Utah desert's Mars-like terrain to simulate working conditions on the red planet. Scientists, students and enthusiasts work together developing field tactics and studying the terrain. All outdoor exploration is done wearing simulated spacesuits and carrying air supply packs and crews live together in a small communication base with limited amounts of electricity, food, oxygen and water. Everything needed to survive must be produced, fixed and replaced on site. (Photo by Jim Urquhart/Reuters)

A demonstrator holds up a picture depicting Russian President Vladimir Putin with make-up, during a protest by the gay community in Amsterdam April 8, 2013. Russia does not discriminate against homosexuals, Putin told reporters in Amsterdam on Monday where he was greeted by gay rights and other activists critical of Russia's track record. Putin is on one-day visit in the Netherlands for the start of the Netherlands-Russia Year. (Photo by Cris Toala Olivares/Reuters)

A girl joins other novice nuns for a lunch at the Sathira-Dhammasathan Buddhist meditation centre in Bangkok April 21, 2013. A group of Thai girls are choosing to spend part of their school holidays as Buddhist nuns, down to having their heads shaven at the meditation centre. The centre, founded in 1987, is a learning community for peace and harmony that has programs open to people regardless of age and gender. (Photo by Damir Sagolj/Reuters)

Tao Xiangli gets out of his homemade submarine after operating it in a lake on the outskirts of Beijing September 3, 2009. Amateur inventor Tao, 34, made a fully functional submarine, which has a periscope, depth control tanks, electric motors, manometer, and two propellers, from old oil barrels and tools which he bought at a second-hand market. He took 2 years to invent and test the submarine which costs 30,000 yuan ($4,385). (Photo by Christina Hu/Reuters)

A demonstrator waves Turkey's national flag as he sits on a monument during a protest against Turkey's Prime Minister Tayyip Erdogan and his ruling AK Party in central Ankara June 2, 2013. Erdogan accused Turkey's main secular opposition party on Sunday of stirring a wave of anti-government protests, as tens of thousands regrouped in Istanbul and Ankara after a lull and trouble flared again in the capital. Police used tear gas on protesters in Ankara but the clashes were relatively minor compared with major violence in Turkey's biggest cities on the previous two days. (Photo by Umit Bektas/Reuters)

Uranjargal, a leader of the Mongolian neo-Nazi group Tsagaan Khass, stands next to a statue of Chingunjav, a Mongolian national hero, in Ulan Bator June 22, 2013. The group has rebranded itself as an environmentalist organisation fighting pollution by foreign-owned mines, seeking legitimacy as it sends Swastika-wearing members to check mining permits. Over the past years, ultra-nationalist groups have expanded in the country and among those garnering attention is Tsagaan Khass, which has recently shifted its focus from activities such as attacks on women it accuses of consorting with foreign men to environmental issues, with the stated goal of protecting Mongolia from foreign mining interests. This ultra-nationalist group was founded in the 1990s and currently has 100-plus members. (Photo by Carlos Barria/Reuters)

Japanese Ground Self-Defense Force's 1st Airborne Brigade soldiers board a CH-47 helicopter for parachute drop training during their military drill at Higashifuji training field in Susono, west of Tokyo, July 8, 2013. Japan faces increasingly serious threats to its security from an assertive China and an unpredictable North Korea, a defence ministry report said on Tuesday, as ruling politicians call for the military to beef up its ability to respond to such threats. (Photo by Issei Kato/Reuters)

Shoppers walk down stairs featuring a five-metre-high reproduction of Vincent van Gogh's signature painting “Sunflowers”, at the entrance to Ocean Terminal in Hong Kong July 15, 2013. A premium three-dimensional reproduction of works of Van Gogh, the RELIEVO collection, approved by the curators of the Van Gogh Museum in Amsterdam, is on display at a gallery inside Harbour City shopping mall attached to the terminal. (Photo by Bobby Yip/Reuters)