Passengers pose for a selfie as they wait for the Night Tube train service at Oxford Circus on the London underground system in London, Britain August 20, 2016. The London Underground is starting its first-ever overnight service, a move city leaders hope will make the British capital a truly 24-hour city and bolster the local economy. (Photo by Paul Hackett/Reuters)

A female Kurdistan Workers Party (PKK) fighter stands near a security position in Sinjar, March 13, 2015. Women fighters at a Kurdistan Workers Party (PKK) base on Mount Sinjar in northwest Iraq, just like their male counterparts, have to be ready for action at any time. Smoke from the front line, marking their battle against Islamic State, which launched an assault on northern Iraq last summer, is visible from the base. Many of the women have cut links with their families back home; the fighters come from all corners of the Kurdish region. (Photo by Asmaa Waguih /Reuters)

A female Kurdistan Workers Party (PKK) fighter works on her laptop while watching a Kurdish TV station at a base in the Sinjar mountains, March 11, 2015. Women fighters at a Kurdistan Workers Party (PKK) base on Mount Sinjar in northwest Iraq, just like their male counterparts, have to be ready for action at any time. Smoke from the front line, marking their battle against Islamic State, which launched an assault on northern Iraq last summer, is visible from the base. Many of the women have cut links with their families back home; the fighters come from all corners of the Kurdish region. (Photo by Asmaa Waguih/Reuters)

Cycling jerseys, part of a collection belonging to French cycling fan Gerald, hang from a line during the 4th stage of the Tour de France cycling race from Seraing in Belgium to Cambrai in France, July 7, 2015. Photographing the Tour de France cycling race comes with highs and lows: the buzz from capturing just the right image, the tedium of long journeys, the painstaking set-up of equipment, the breath-taking scenery. Reuters photographers have worked not only to capture the thrills and spills on the roads and mountain passes. They have also shot a set of pictures showing their own quirky view from behind the scenes as they travelled through the Netherlands, Belgium and France. (Photo by Eric Gaillard/Reuters)

“Bazooka”, a one year old stray cat, is treated at the SPCA (Society for Prevention of Cruelty to Animals) clinic in Tel Aviv, Israel, 06 January 2016. Bazooka arrived at the clinic in critical condition after he went through severe abuse with bruises all over his body and painted with pink oxidation. The Israeli street cat population is estimated to be about two million. Without enough financial support from the state, animal rights organizations find it difficult to keep the up with the pace when it comes to spaying and neutering feral cats, causing the population to grow. (Photo by Abir Sultan/EPA)

From Britain to China to Mali, new maps showing travel times to the nearest urban centre reveal huge differences between countries. Using Open Street Map and Google, a University of Oxford team have created a visual breakdown that suggests major inequalities when it comes to commuting. Here: China. The dataset used for China was unique as it relied solely on Open Street Map, due to restrictions on accessing Google data. The population is densely concentrated in the east and accessibility is increased, whereas rural provinces in the west remain remote. (Photo by Daniel Weiss/Jennifer Rozier/Malaria Atlas Project/University of Oxford)

The sea otter mother with her three day old newborn pup ontop of her to keep it dry and warm while it sleeps. This devoted mother otter kept her newborn pup dry as she let the baby ride on her belly. Nature photographer Suzi Eszterhas, 40, spotted the adorable pair of southern sea otters swimming in Monterey Bay, California. The mother lifted the pup out of the water and on to her belly to keep it warm and dry and also blew air into the pup's fur to groom it. Ms Eszterhas was shocked to see the otters come closer to where she was standing and the mother left her child to float alone in the water. (Photo by Suzi Eszterhas/Minden Pictures/Solent News & Photo Agency)

A young girl splashes through a waterfall at a park in Washington, DC, on June 28, 2021, as a heatwave moves over much of the United States. Swathes of the United States and Canada endured record-setting heat on June 27, 2021, forcing schools and Covid-19 testing centers to close and the postponement of an Olympic athletics qualifying event, with forecasters warning of worse to come. The village of Lytton in British Columbia broke the record for Canada's all-time high, with a temperature of 46.6 degrees Celsius (116 Fahrenheit), said Environment Canada. (Photo by Jim Watson/AFP Photo)