People walk through crop circles in a cornfield near Raisting, Germany, on July 28, 2014. According to media reports, a balloonist had discovered the circle some days ago. Since then, hundreds of people came to the field to watch it, however it is unclear who did create the pattern. (Photo by Karl-Josef Hildenbrand/DPA)

An armed man herds his cattle close to the village of Nimini in northern South Sudan, February 8, 2017. In the chaos of South Sudan's civil war, it took three years for Nyagonga Machul to find her lost children. Machul had traveled from her village to the capital when President Salva Kiir, an ethnic Dinka, fired his deputy Riek Machar, a Nuer, in 2013. (Photo by Siegfried Modola/Reuters)

Since 2003, photographer Sergey Fomin has been shooting Russia’s most attractive natural, historical, and architectural objects from different aircrafts. Photo: “An Explosive Scene”. The 1,486-meter-high Karymskii Volcano in Kamchatka. (Photo by Sergey Fomin)

A leopard seal feeds Paul Nicklen a penguin. (Photo by Paul Nicklen/National Geographic). Antarctic Peninsula, 2011

Galapagos – Rocking the Cradle: Four major ocean currents converge along the Galapagos archipelago, creating the conditions for an extraordinary diversity of animal life, April 25, 2016. The islands are home to at least 7,000 flora and fauna species, of which 97 percent of the reptiles, 80 percent of the land birds, 50 percent of the insects and 30 percent of the plants are endemic. (Photo by Thomas P. Peschak for National Geographic/World Press Photo)

The Aurora Borealis (Northern Lights) is seen over the sky near Inari in Lapland, Finland on February 14, 2019. (Photo by Alexander Kuznetsov/Reuters)

In this March 20, 2016 photo, Maj. Mohammed Hussein, an officer with Iraq's elite counterterrorism forces, shows a photo of a slain Islamic State group militant still wearing in a suicide vest, taken during fighting that freed the city of Ramadi from IS control earlier this year. As they fled, the militants destroyed some buildings and booby-trapped others with explosives, leaving behind an empty prize for government forces retaking the city. (Photo by Maya Alleruzzo/AP Photo)

A groundskeeper uses a bamboo broom at Kasumigaike Pond at Kenrokuen Garden in Kanazawa, Japan on January 12, 2016. The japanese garden, located next to Kanazawa Castle, encompasses over 28 acres in downtown Kanazawa. With two ponds, rolling hills with streams and bridges, is considered a strolling-style landscape garden. It's regarded as one of the top three most beautiful gardens in Japan. (Photo by Linda Davidson/The Washington Post)