Bangladeshi Muslim devotees arrive in an over-crowded train to attend the final day of an Islamic congregations' first phase in Tongi, 20 kilometers (13 miles) north of Dhaka, Bangladesh, Sunday, January 10, 2016. The second phase of the annual event, one of the world's largest congregations of Muslims is scheduled to begin Friday. (Photo by A.M. Ahad/AP Photo)

People watch police destroy confiscated illegal firecrackers in Shenyang, Liaoning province, China, January 29, 2016. (Photo by Reuters/Stringer)

A North Korean soldier kicks a pole along the bank of Yalu River near the North Korean town of Sinuiju, opposite the Chinese border city of Dandong, February 4, 2014. (Photo by Jacky Chen/Reuters)

A picture taken with slow shutter speed shows members of the group “The Kattfiller” from Attendorn taking part during the Norddeutsche Championship carnivalesque dance sport in Kassel (Hessen), Germany, 28 February 2016. About 1,100 qualified dancers show in different disciplines their skills. (Photo by Swen Pfoertner/EPA)

A fisherman carries a sailfish on his head to the fish market in Hamarweyne near the port of Mogadishu on April, 4, 2016. (Photo by Mohamed Abdiwahab/AFP Photo)

Ukrainians pour water on each other on a street in Lviv, Ukraine, 02 May 2016. The tradition of pouring water was an ancient spring ritual of cleansing on first Monday after Orthodox Easter. (Photo by Mykola Tys/EPA)

A man strikes a pose in front of a giant torta, or sandwich, during a press conference to promote the 13th annual Torta Festival, in Mexico City, Wednesday, July 20, 2016. The five day festival presents a variety of the Mexican street food made from the most exotic ingredients that include ostrich or stingray, to the classic ham, grilled steak or slow cooked pork. The festival's purpose is to maintain the tradition of eating tortas, and promote the vendors of the Mexican sandwich. (Photo by Marco Ugarte/AP Photo)

The NASA Extreme Environment Mission Operations (NEEMO) 21 mission began on July 21 as an international crew of aquanauts splashed down to the undersea Aquarius Reef Base, located 62 feet below the surface of the Atlantic Ocean in the Florida Keys National Marine Sanctuary. The NEEMO 21 crew will perform research both inside and outside the habitat during a 16-day simulated space mission. During simulated spacewalks carried out underwater, they will evaluate tools and mission operation techniques that could be used in future space missions, including journeys to Mars. (Photo by Karl Shreeves/NASA)