Germany's Angelique Kerber reacts after popping a bottle of champagne, a day following her win in the final match at the Australian Open tennis tournament, at the Government House in Melbourne, Australia, January 31, 2016. (Photo by Issei Kato/Reuters)

Schoolchildren perfom during celebrations to mark 35 years of Zimbabwe's Independence at the National sports stadium in Harare, Saturday, April 18, 2015. President Robert Mugabe, 91, the central figure in Zimbabwean politics 35 years after Independence from Britain, has led the country since 1980. (Photo by Tsvangirayi Mukwazhi/AP Photo)

Actors reenact the famous picture of a sailor kissing a nurse on the 70th anniversary of Victory over Japan Day, near a replica sculpture in New York's Times Square August 14, 2015. The replica is being displayed to celebrate the 70th anniversary of the iconic photograph of the most famous kiss in American history that was captured between an American sailor and nurse on August 14, 1945, marking the end of World War Two. The actors are hired by a tour bus company to pose for groups to photograph. (Photo by Brendan McDermid/Reuters)

An urban fox walks alongside the Mall in central London, Britain, November 29, 2016. (Photo by Toby Melville/Reuters)

A woman is led aside as her partner is detained by Ukrainian security forces for being aggressive at an army checkpoint in the southeastern port city of Mariupol, on May 11, 2014. Residents’ attitudes appear to have hardened considerably with the deaths of dozens of pro-Russian activists in the city of Odessa this month and with reports that troops fired at a crowd in Mariupol last week. (Photo by Marko Djurica/Reuters)

In this Thursday, May 8, 2014 photo, Iranian coal miners push metal carts to be loaded with coal at a mine near the city of Zirab 212 kilometers (132 miles) northeast of the capital Tehran, on a mountain in Mazandaran province, Iran. International sanctions linked to the decade-long dispute over Iran's nuclear program have hindered the import of heavy machinery and modern technology in all sectors, and coal mining is no exception. (Photo by Ebrahim Noroozi/AP Photo)

“The V-30 Warhawk was designed by Blackshaw Avionics as a long-range fighter and was primarily used by the Arcadian Air Force for escort duties. The plane pictured is the “Spirit of Freedom” and was one of the four planes that escorted the Arcadian Royal Airship during and after the Great War. The three other fighters were the “Spirit of Hope”, the “Spirit of Justice” and the “Spirit of Destiny”. All pilots were hand-picked by the Head of Airborne Forces and included some of the very finest pilots in the Kingdom. The crew consisted of one pilot and one gunner although both cabins were fitted so that if either crew member was killed the other could take over their duties. Each Warhawk was fitted with four Haverlock “Banshee” engines and four 24mm machine guns”. (Photo and comment by Jon Hall)

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)