A weeping South Vietnamese mother and her three children are shown on the deck of this amphibious command ship being plucked out of Saigon by U.S. Marine helicopters in Vietnam, April 29, 1975. (Photo by AP Photo)

A meteorite burns up in the atmosphere as seen in this photo taken near of Salgotarjan, 109 kms northeast of Budapest, Hungary, late 21 April 2015. The Moon and Venus can be seen on the left. (Photo by Peter Komka/EPA)

A man sleeps on a wheelbarrow outside a closed shop at a market during the first day of a ceasefire in Yemen's capital Sanaa April 11, 2016. (Photo by Khaled Abdullah/Reuters)

Residents ride on top of an overcrowded “Jeepney”, a locally manufactured public transport, along a highway in Mogpog town on Marinduque island in central Philippines April 8, 2015. (Photo by Erik De Castro/Reuters)

Racegoers attend day one of The Randox Health Grand National Festival at Aintree Racecourse on April 12, 2018 in Liverpool, England. (Photo by News Group Newspapers Ltd)

Brazilian singer Anitta performs during the show of the Agua de Coco collection at Sao Paulo Fashion Week in Sao Paulo, Brazil, Saturday, April 21, 2018. (Photo by Andre Penner/AP Photo)

Festivalgoers during the 2018 Coachella Valley Music And Arts Festival at the Empire Polo Field on April 20, 2018 in Indio, California. (Photo by Frazer Harrison/Getty Images for Coachella)

Models present creations by Shana Morland during the African Fashion International (AFI) Cape Town Fashion Week, in Cape Town, South Africa, 13 April 2019. (Photo by Nic Bothma/EPA/EFE)