A “creuseur”, or digger, a plastic lantern on his head, readies to enter a copper and cobalt mine in Kawama, Democratic Republic of Congo on June 8, 2016. Cobalt is used in the batteries for electric cars and mobile phones. Working conditions are dangerous, often with no safety equipment or structural support for the tunnels. The diggers say they are paid on average US$2-3/day. (Photo by Michael Robinson Chavez/The Washington Post)

A Cuban migrant couple rests inside a tent at a provisional shelter in Paso Conoa, at the border with Costa Rica March 20, 2016. More than 1,500 Cuban immigrants are waiting at Costa Rica's southern border with Panama as they seek overland passage towards the United States, according to local officials. (Photo by Carlos Jasso/Reuters)

Supporters of Filipino boxer and Senatorial candidate Manny Pacquiao, wait for election souvenirs thrown by Pacquiao during election campaigning in Malabon Metro Manila in the Philippines May 6, 2016. Boxing star Manny Pacquiao pressed on with his campaign for a seat in the Philippine Senate despite a reported militant plot to kidnap him. (Photo by Erik De Castro/Reuters)

Prostitutes working on 10th Ave in New York, USA on June 29, 1997. (Photo by Jon Naso/NY Daily News Archive via Getty Images)

Revellers in Blackpool kept the bank holiday party going on May 30, 2018, taking full advantage of the warm weather and long weekend to let rip. The bank holiday booze up continued across Britain with one party-goer managing to accidentally flash her knickers in public. A bank holiday is a public holiday in the United Kingdom and some Commonwealth countries. (Photo by NB Press Ltd/The Sun)

North Korean youngsters sing and play accordions to entertain foreign visitors including United Nations Secretary General Kurt Waldheim, who visited Pyongyang, May 4, 1979. Visitors report music education in North Korea begins at an early age and is taken seriously by children and adults. (Photo by Peter Arnett/AP Photo)

Video bloggers stream live broadcast of an event to celebrate the fourth birthday of the world's only giant panda triplets, Meng Meng, Shuai Shuai and Ku Ku, at Chimelong Safari Park in Guangzhou, China July 29, 2018. (Photo by Bobby Yip/Reuters)

A handout photo made available by the NASA shows the United Launch Alliance Delta IV Heavy rocket launches NASA's Parker Solar Probe to touch the Sun, from Launch Complex 37 at Cape Canaveral Air Force Station, Florida, USA, 12 August 2018. Parker Solar Probe is humanity’s first-ever mission into a part of the Sun’s atmosphere called the corona. Here it will directly explore solar processes that are key to understanding and forecasting space weather events that can impact life on Earth. (Photo by Bill Ingalls/EPA-EFE/NASA)