The Doppler on Wheels (DOW) vehicle scans a supercell thunderstorm during a tornado research mission, May 8, 2017 in Elbert County near Agate, Colorado. Doppler on Wheels (DOW) is a mobile doppler radar mounted on a truck that brings instruments directly into storms, allowing scientists to scan storms and tornadoes and make 3-D maps of wind and debris. (Photo by Drew Angerer/Getty Images)

A family of refugees shelters under a truck carrying plastic lota, kettles used to perform Muslim ablutions in Muna Garage, Maiduguri, Nigeria February 16, 2017. (Photo by Paul Carsten/Reuters)

A bonnet macaque sits on consecrated idols of snakes as it drinks milk offered by a devotee during the Hindu festival of Nag Panchami, which is celebrated by worshipping snakes to honour the serpent god, inside a temple on the outskirts of Bengaluru, India, July 27, 2017. (Photo by Abhishek N. Chinnappa/Reuters)

Passengers travel in an overcrowded train in the eastern Indian city of Patna, February 23, 2010. (Photo by Krishna Murari Kishan/Reuters)

A boy dressed as Lord Krishna is pictured while Hindu devotees march on the streets to celebrate Janmashtami festival, which marks the birth anniversary of Lord Krishna, in Dhaka, August 14, 2017. (Photo by Mohammad Ponir Hossain/Reuters)

People protest at the Boston Free Speech Rally in Boston, USA on August 19. 2017. With the Boston Free Speech rally was closed to the media (despite the Boston Common being a public space), a lot of the media’s coverage centred on the tensions within the larger counter-protest. (Photo by Stephanie Keith/Reuters)

Londoners enjoy a “Silent Night” as Big Ben falls silent, London, UK on August 21, 2017. ose Allerston from Clapham, London said “After a stressful day in the office, I couldn't think of anything better than going home and climbing into bed – but when I saw this bed opposite Big Ben I just couldn't resist getting in for a snuggle”. (Photo by Imagewise Ltd/Rex Features/Shutterstock)

This image of a young bareback rider was taken in the village of Palenque de San Basilio, in Colombia’s Bolívar department. Founded by freed slaves in the 17th century, it became the first free town in the Americas, following a decree by the Spanish crown. Most of today’s inhabitants are direct descendants of those slaves and have preserved many of their customs, including their own language, Palenquero. (Photo by Sebastián Suki Beláustegui/The Guardian)