Two female soldiers have their picture taken by an army colleague at Mangyongdae. (Photo by Gavin John/Mediadrumworld.com)

The Doppler on Wheels (DOW) vehicle scans a supercell thunderstorm during a tornado research mission, May 8, 2017 in Elbert County near Agate, Colorado. Doppler on Wheels (DOW) is a mobile doppler radar mounted on a truck that brings instruments directly into storms, allowing scientists to scan storms and tornadoes and make 3-D maps of wind and debris. (Photo by Drew Angerer/Getty Images)

A couple takes a selfie as Hoa Binh hydroelectric power plant opens the flood gates after a heavy rainfall caused by Talas typhoon in Hoa Binh province, outside Hanoi, Vietnam July 20, 2017. (Photo by Reuters/Kham)

An Indian worker paints the hand of a huge clay model of a tribal woman on the Indian state of Karnataka's tableau for Republic Day parade, in New Delhi, India, Friday, January 22, 2016. Security has been tightened around the Indian capital as well as across the country ahead of Republic Day celebrations, held each year on Jan. 26. (Photo by Manish Swarup/AP Photo)

A wide-angle view shows the ascent of the shuttle Challenger on January 28, 1986. In the seconds after ignition, the rocket engines' hot blast began the process of destruction. (Photo by NASA)

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)

Female of pygmy hippopotamus called Malaya from Netherlands in zoo in Dvur Kralove nad Labem, Czech Republic, February 22, 2016. (Photo by David Tanecek/CTK via ZUMA Press)

A boy dressed as Lord Krishna is pictured while Hindu devotees march on the streets to celebrate Janmashtami festival, which marks the birth anniversary of Lord Krishna, in Dhaka, August 14, 2017. (Photo by Mohammad Ponir Hossain/Reuters)