A supporter of the Houthi movement attends a rally marking the birth anniversary of Prophet Mohammed, in Sanaa, Yemen December 11, 2016. (Photo by Khaled Abdullah/Reuters)

Team Strong Silvers member Ngai Hin Kwok, 66, works out as teammate Ng Siu Chi, 57, watches at a stadium in Singapore March 15, 2015. Team Strong Silvers, is a group of senior citizens who train in calisthenics. The trio trains individually at least three times a week, and meets up for joint calisthenics at least twice a month. (Photo by Edgar Su/Reuters)

A Kurdish female fighter from the People's Protection Units (YPG) gestures as she carries her weapon near al-Hawl area where fighting between Islamic State fighters and fighters from Democratic Forces of Syria are taking place in south-eastern city of Hasaka, Syria November 10, 2015. (Photo by Rodi Said/Reuters)

ESA astronaut Tim Peake posted this stunning image on his social media channels, commenting: “Station passed through magnificent aurora Australis last night”. Tim is set to return to Earth on 18 June 2016, bringing his six-month Principia mission to the ISS to an end. During his stay he performed more than 30 scientific experiments for ESA and taking part in numerous others from ESA's international partners. ESA and the UK Space Agency have partnered to develop many exciting educational activities around the Principia mission, aimed at sparking the interest of young children in science and space. (Photo by Tim Peake/ESA/NASA)

Michael Pankratz’s intriguing works focus specifically on the feet of tarantulas – an appendage that many have perhaps never focused on. The extreme close-ups of tarantulas’ “paws” show fine, colourful hairs, and sharp claws. Here: Brachypelma albopilosum, foot detail. (Photo by Michael Pankratz/Caters News Agency)

A woman in the Sabean Mandaean community takes part in a ritual during the Prosperity Day celebration in the Tigris River in central Baghdad, Iraq, Tuesday, November 1, 2022. (Photo by Hadi Mizban/AP Photo)

Cars drive under a rainbow near Bad Langensalza, Germany, Wednesday, November 2, 2016. (Photo by Jens Meyer/AP Photo)

“Mr Big Dipper”, Nicholas Roemmelt (Denmark). A stargazer observes the constellation of the Big Dipper perfectly aligned with the window of the entrance to a large glacier cave in Engadin, Switzerland. This is a panorama of two pictures, and each is a stack of another two pictures: one for the stars and another one for the foreground, but with no composing or time blending. (Photo by Nicholas Roemmelt/National Maritime Museum/The Guardian)