The setting sun illuminates the sky behind wind turbines of a wind park near Neusiedl am See, December 22, 2014. (Photo by Heinz-Peter Bader/Reuters)

A comedic photo of a cheetah appearing to find something hilarious by Dutton Robert for the Comedy Wildlife Photo Awards 2016, South Africa, April, 2012. (Photo by Dutton Robert/Barcroft Images/Comedy Wildlife Photo Awards)

Fighters from the Democratic Forces of Syria prepare their weapons in the southwestern countryside of Hasaka, Syria February 17, 2016. Picture taken February 17, 2016. (Photo by Rodi Said/Reuters)

A woman selling souvenirs walks through Kuta beach in Bali June 5, 2008. Indonesia is expected to report tourist arrivals in December this week. (Photo by Murdani Usman/Reuters)

Russian soldiers from 34th motorized infantry mountain brigade, 58th Army, prepare to evacuate a fellow soldier acting as an injured person during a drill at the Darial range outside Russia's city of Vladikavkaz, July 28, 2010. (Photo by Kazbek Basayev/Reuters)

The players of Denmark huddle prior to the FIFA Women's World Cup qualifier match between Denmark and Sweden at Viborg Stadion on September 4, 2018 in Viborg, Denmark. (Photo by Lars Ronbog/FrontZoneSport via Getty Images)

Girls dressed up in traditional Egyptian clothes from the early 20th century pose for a picture before they get their photos taken on the historical Al-Moez street of Islamic Cairo, Egypt, January 17, 2016. (Photo by Asmaa Waguih/Reuters)

The competition, which is run by the Royal Observatory Greenwich in association with BBC Sky at Night Magazine, is now in its sixth year and has received over 2,500 entries. Photo: Centre of the Heart Nebula by Ivan Eder (Hungary). Situated 7500 light years away in the “W”-shaped constellation of Cassiopeia, the Heart Nebula is a vast region of glowing gas, energized by a cluster of young stars at its centre. The image depicts the central region, where dust clouds are being eroded and moulded into rugged shapes by the searing cosmic radiation. (Photo by Ivan Eder)