A mudlark uses a torch to look for items on the bank of the River Thames in London, Britain June 06, 2016. Mudlarking is believed to trace its origins to the 18th and 19th century, when scavengers searched the Thames' shores for items to sell. These days, history and archaeology fans are the ones hoping to find old relics such as coins, ceramics, artifacts or everyday items from across centuries. their finds with the Portable Antiquities Scheme. Any item over 300 years old must be recorded. (Photo by Neil Hall/Reuters)

A woman loyal to the Houthi movement holds a rifle as she takes part in a parade to show support to the movement in Sanaa, Yemen September 6, 2016. The Saudi-led Arab coalition launched a military campaign against the Huthis and their allies in March 2015, after the rebels closed in on Gulf-backed President Abedrabbo Mansour Hadi in his southern refuge of Aden, forcing him into exile. (Photo by Khaled Abdullah/Reuters)

(L-R) Maria Silva, Milena Cortes, Maria Arteaga, Jackeline Bastidas and Gissy Abello pose for a picture at the Famproa dogs shelter where they work, in Los Teques, Venezuela, August 25, 2016. Venezuelans struggling to feed their families let alone their pets are dumping animals on the streets, in parks and at makeshift homes overrun with scrawny animals amid an economic crisis. An hour from Caracas in Los Teques, hundreds of dogs bark and run around the streets scavenging for food outside a makeshift shelter. (Photo by Carlos Garcia Rawlins/Reuters)

A crane loads logs at the Novoyeniseisk wood processing plant, with the air temperature at about minus 20 degrees Celsius (minus 4 degrees Fahrenheit), in the town of Lesosibirsk in Krasnoyarsk Region, Siberia, Russia, February 16, 2016. The plant exports timber to Europe, Northern Africa and Asia. The Taiga, also known as the boreal forest, on the coast of the Angara River and Yenisei River is one of the main areas for the industrial cutting of wood thanks to the high quality of the Angara pine. Open air work continues all year around regardless to temperatures which can drop to minus 52 degrees Celsius (minus 61.6 degrees Fahrenheit), according to employees. (Photo by Ilya Naymushin/Reuters)

A pigeon, known as Siyah Kinifirli, with an approximate market value of 1000 Turkish Lira ($263), bred by 23-year-old Ismail Ozbek, is pictured in Sanliurfa, Turkey, December 23, 2016. As night-time approaches in Sanliurfa, southeastern Turkey, most of the alleyways of the city's old bazaar are emptying out of buyers and vendors, except for one. (Photo by Umit Bektas/Reuters)

A little girl holding her newborn sister waits for their turn in a queue during a vaccination campaign under the supervision of the Syrian Arab Red Crescent (SARC) humanitarian nonprofit organization, in the besieged Syrian town of Douma, Syria, 23 May 2017. According to a statement from SARC, in the city of Douma some 12,809 children under the age of five were immunized in a vaccination campaign to prevent measles and poliomyelitis. The campaign was the first of its kind with the participation of 100 volunteers. SARC has been delivering vaccines to 17 health centers approved for vaccination campaigns in towns and villages in the Eastern Ghouta area. (Photo by Mohammed Badra/EPA)

Flames from a burning barricade lit by pro-democracy protesters is reflected in the windows of a passing bus as passengers watch on during a protest gathering in front of Mong Kok police station on September 22, 2019 in Hong Kong, China. Pro-democracy protesters have continued demonstrations across Hong Kong, calling for the city's Chief Executive Carrie Lam to immediately meet the rest of their demands, including an independent inquiry into police brutality, the retraction of the word “riot” to describe the rallies, and genuine universal suffrage, as the territory faces a leadership crisis. (Photo by Chris McGrath/Getty Images)

NASA handout photographs from the various Apollo missions are shown in this combination photograph. The photographs are some of more than 12,000 from NASA's archives recently aggregated on the Project Apollo Archive Flickr account. (Top L) David R. Scott, command module pilot, stands in the open hatch of the Command Module during the Apollo 9 mission March 6, 1969. (Top centre) Edwin "Buzz" Aldrin Jr.walks on the surface of the moon during the Apollo 11 mission July 20, 1969. (Top R) Neil Armstrong, Apollo 11 commander, is pictured inside the Lunar Module during the Apollo 11 mission July 20, 1969. (Bottom L) Alan Bean holds a container filled with lunar soil collected during the Apollo 12 mission November 19, 1969. (Bottom centre) Scientist-astronaut Harrison Schmitt rides in the Lunar Roving Vehicle during the Apollo 17 mission December 13, 1972. (Bottom R) Harrison Schmitt stands next to a huge, split boulder during the Apollo 17 mission December 13, 1972. (Photo by Reuters/NASA)