Students wearing mask hold hands to surround the St. Stephen's Girls' College in Hong Kong, Monday, September 9, 2019. Thousands of demonstrators in Hong Kong urged President Donald Trump to “liberate” the semiautonomous Chinese territory during a peaceful march to the U.S. Consulate on Sunday, but violence broke out later in the business and retail district as police fired tear gas after protesters vandalized subway stations, set fires and blocked traffic. (Photo by Kin Cheung/AP Photo)

A member of staff stands in front of a CRH high-speed train at Shanghai Hongqiao Railway Station during its test run on May 11, 2011 in Shanghai, China. After 3 years construction, from April in 2008, with total investment estimated at 220.9 billion yuan (around 32.5 billion U.S. dollars), the Beijing-Shanghai high-speed railway begins a one-month trial operation. It is expected to start operation in June this year, with the travel time between the two cities reducing to five hours from the previous 10. (Photo by ChinaFotoPress/Getty Images)

Arrow sports his new elastic booties at a PetSmart in Tempe, Ariz. on Tuesday, June 20, 2017. Phoenix radio station KSLX handed out the protective coverings to protect dogs' paws from the hot pavement, as temperatures in Phoenix are forecasted to hit 120 degrees (48°C). (Photo by Angie Wang/AP Photo)

A man crosses from a pirogue to another pirogue during the annual boat regatta in Yauri, Kebbi State, on February 15, 2025. The regatta festival started about 200 years ago as a display of naval strength of the Gungu people, where the Gungu warriors annually attacked dangerous hippopotamus that were destroying farmlands. Warriors would board various sizes of canoes with different types of weapons to attack the animal on the River Niger. This required expertise in canoe paddling and naval warfare. It also served as training exercise for upcoming Gungu warriors. (Photo by Toyin Adedokun/AFP Photo)

Sеx worker Geraldine, wearing cat make-up, excitedly holds up a dress she is thinking of buying from a street vendor, so that her partner, sitting nearby to keep her company, can see it, as she waits for clients outside the Revolution subway station, in Mexico City, Saturday, March 13, 2021. According to Geraldine, 30, the pandemic has cut clients and increased risks to the sеx workers but has also brought out more assistance for them too, both from dedicated organizations such as the activist group Brigada Callejera or “The Street Brigade” and from individuals who have donated food or clothing. (Photo by Rebecca Blackwell/AP Photo)

Police officers take cover as they clash with protesters after an officer shot and killed a black man in Brooklyn Center, Minneapolis, Minnesota on April 11,2021. Protests broke out April 11, 2021 night after US police fatally shot a young Black man in a suburb of Minneapolis – where a former police officer is currently on trial for the murder of George Floyd. Hundreds of people gathered outside the police station in Brooklyn Center, northwest of Minneapolis. Police fired teargas and flash bangs at the demonstrators, according to an AFP videojournalist at the scene. (Photo by Kerem Yucel/AFP Photo)

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)