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)

“For a bouquet of flowers”. Photographs made ​​in the last hours of the day. A goat is directed by a dangerous way to eat a small bouquet of flowers. Location: España, Barcelona, Montserrat. (Photo and caption by Renato Lopez Baldo/National Geographic Traveler Photo Contest)

ATTENTION! All pictures are presented in high resolution. To see Hi-Res images – just TWICE click on any picture. In other words, click small picture – opens the BIG picture. Click BIG picture – opens VERY BIG picture.

A man rides his horse next to Kosovo's coal-fired power plant near the town of Obilic on May 30, 2022. Two coal-fired power plants, Kosova A and Kosova B, are the main source of the alarming air pollution levels in Kosovo, and particularly in the town of Obilic, which is located between the two plants and near to their ash disposal sites and open-pit lignite mines. (Photo by Armend Nimani/AFP Photo)

Sierra “Lovely Amazin” Redd of Greensboro, North Carolina, poses for bikers by a custom Suzuki Katana on Ocean Boulevard during the 2015 Atlantic Beach Memorial Day BikeFest in Myrtle Beach, South Carolina May 24, 2015. (Photo by Randall Hill/Reuters)

Joanne Froggatt poses with her award for Best Supporting Actress in a Series, Mini-Series or TV Movie for her role in “Downton Abbey” backstage at the 72nd Golden Globe Awards in Beverly Hills, California January 11, 2015. (Photo by Mike Blake/Reuters)

An Afghan Army soldier secures the hill overlooking the Kart-e Sakhi mosque in Kabul, Afghanistan, Wednesday, March 20, 2013. Thousands of Afghans will celebrate Nowruz on Thursday, March 21, 2013 to mark the first day of spring and the beginning of the year on the Iranian calendar. (Photo by Ahmad Jamshid/AP Photo)

A Dongria tribe girl holds her traditional weapon and dance on the last day of their two days long Niyamraja Festival atop of the Niyamgiri hills near Lanjigarh in Kalahandi district, Orissa state. (Photo by Biswaranjan Rout/AP Photo)

An Afghan girl carries water on her back as she climbs a hill in Kabul, Afghanistan February 20, 2017. A growing population is straining water supplies in Afghanistan's capital, forcing those who can afford it to dig unregulated wells ever deeper to tap a falling water table. Finding water in arid Afghanistan is virtually always a challenge, but a drop in the groundwater level in Kabul caused by overuse and drought is making it even more difficult for residents, especially the poor. (Photo by Omar Sobhani/Reuters)