Thanks to plenty of salt minerals and heavy elements in the soil, the Dallol volcano in Ethiopia produces brilliantly colored pools of water at the top of its caldera. And, as if to add greater effect to the already stunning sights, the volcano stands apart from the salt plains around it like an island. This hotspot was created through phreatomagmatic eruptions caused by magma interacting with water, and was further altered due to the presence of salt water. (Photo by Francisco Pandolfo/Caters News)

A fog bow is a similar phenomenon to a rainbow; however, as its name suggests, it appears as a bow in fog rather than rain. Because of the very small size of water droplets that cause fog—smaller than 0.05 millimeters (0.0020 in)—the fog bow has only very weak colors, with a red outer edge and bluish inner edge.

A woman prays at the edge of a river during a protest against the building of a pipeline near the Standing Rock Indian Reservation near Cannonball, North Dakota, U.S. November 2, 2016. (Photo by Stephanie Keith/Reuters)

An air tanker flies low over a wildfire burning on the edge of the Cariboo region city of Williams Lake, British Columbia, Canada on July 21, 2024. (Photo by Spencer Stratton/Handout via Reuters)

Truffle hunter Carlo Marenda pets his dog Buc as they search for white truffles through the Langhe Countryside in Roddi, near Alba, north-western Italy, on November 8, 2020. Despite new measures to stop the spread of the Covid-19, truffles hunters are allowed to search in the countryside in Italy. (Photo by Marco Bertorello/AFP Photo)

Vietnamese artist Hoang Tien Quyet produces curved paper forms using a difficult technique known as wet-folding. This adds an element of sculpture to the work, making Hoàng’s origami animals truly remarkable. Too little water and the paper dries before the folding is done; too much water, and the paper will rip.

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)

A steam traction engine with a broken rear axle in Pall Mall, London. (Photo by Topical Press Agency/Getty Images). November 1923