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 woman (L) places flowers at a grave next to a mummified body during exhumation works at the General Cemetery in Guatemala City, April 15, 2015. If a lease on a grave has expired or not been paid, grave cleaners will break open the crypts to remove and rebury the bodies. Any remains that have not been claimed are packed into plastic bags, labeled and stored in mass graves. Bodies that have been stored in the upper crypt are exposed to dry and sunny conditions which means they do not decompose and instead become mummified. (Photo by Jorge Dan Lopez/Reuters)

A player breaks with the bottle during the bottle-kicking game in Hallaton, central England April 6, 2015. The game is played between Hallaton and the neighbouring village of Medbourne each Easter Monday in which participants compete to bring the bottle across a stream that separates the villages. The bottle is an old field barrel holding about a gallon of beer. (Photo by Darren Staples/Reuters)

Japan Self-Defense Force (JSDF) soldiers and firefighters make rescue works among mountain lodges, covered with volcanic ash near the peak of Mt. Ontake, which straddles Nagano and Gifu prefectures in this September 28, 2014 photo taken and released by Kyodo. More than 30 people were feared dead on Sunday near the peak of the Japanese volcano that erupted a day earlier, sending a huge cloud of ash and rock tumbling down its slopes, while packed with hikers. (Photo by Reuters/Kyodo News)

Women tear the shirt off a man during “Huranga”, a game played between men and women a day after Holi, at Dauji temple near Mathura, March 14, 2017. (Photo by Adnan Abidi/Reuters)

Artists perform during the Closing Ceremony of the Rio 2016 Olympic Games at the Maracana Stadium in Rio de Janeiro, Brazil, 21 August 2016. (Photo by Sergei Ilnitsky/EPA)

A young boy adjusts his friend's Adolf Hitler mask during a game on a street in King's Cross, London. (Photo by William Vanderson/Getty Images). 1938

Mongolian Chinese performs a traditional Chinese dance in front of the Olympic Rings located near the National Stadium, the main stadium for the 2020 Tokyo Olympic Games in Tokyo, Japan July 29 2021. (Photo by Androniki Christodoulou/Reuters)