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)

A picture shows the full moon during a “blood moon” eclipse over the temple of Apollo in Corinth on July 27, 2018. The longest “blood moon” eclipse this century began on July 27, coinciding with Mars' closest approach in 15 years to treat skygazers across the globe to a thrilling celestial spectacle. (Photo by Valerie Gache/AFP Photo)

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)

A man in a wartime uniform, poses for a photo on an abandoned tank at a beach, ahead of the 60th anniversary of Second Taiwan Straits Crisis against China, in Kinmen, Taiwan on August 19, 2018. (Photo by Tyrone Siu/Reuters)

Women lie in the sun in Domino Park as high temperatures hit the region in Brooklyn, New York, U.S., August 29, 2018. (Photo by Andrew Kelly/Reuters)

A ballet dancer practices in the sunshine at the Southbank skatepark in London on Monday, September 17, 2018, as Storm Helene is due to bring unseasonably warm weather in London and the south east, as the low pressure draws up warm air from the south. Forecasters have downgraded warnings that Helene could pose a risk to life when it hits this week – but warned coastal communities to stay vigilant. (Photo by Kirsty O'Connor/PA Wire)

Protestors Stacie Ellen Murphy, Alanna Cassidy and Lena Seale walk in their Underwear on Grafton Street in Dublin, support of victims of sexual violence in Irerland on Wednesday, November 16, 2018. (Photo by PA Wire)

In this October 27, 1983 file photo, soldiers brandish captured AK-47 rifles from the windows of a civilian vehicle as they drive near Point Salines Airport in St. George, Grenada. In 1983, U.S. forces invaded the Caribbean island of Grenada after accusing the government of allying itself with Communist Cuba. (Photo by Doug Jennings/AP Photo)