Afghan police officers secure a transportation headquarters that was besieged for two days last weekend, on May 14, 2011 in Kandahar, Afghanistan. Taliban gunmen and suicide bombers unleashed a major assault May 7, 2011 on locations in Kandahar that included the governor's compound, the mayor's office, police stations, and an intelligence agency headquarters. (Photo by Majid Saeedi/Getty Images)

“Contrails (short for “condensation trails”) or vapour trails are artificial clouds that are the visible trails of condensed water vapour made by the exhaust of aircraft engines. As the hot exhaust gases cool in the surrounding air they may precipitate a cloud of microscopic water droplets or, if the air is cold enough, tiny ice crystals”. – Wikipedia

Photo: An airplane leaves a vapor trail as it flies in front of he moon on January 17, 2007 above Hanover, Germany. (Photo by Alexander Hassenstein/Getty Images)

A period of relative stability has put the Iranian capital No1 on the list of world cities that have achieved biggest improvements in liveability over the past five years, as calculated by the Economist Intelligence Unit. The “most improved” top 10 contains some unexpected names. So, eg, the fourth place: Abidjan, Ivory Coast. Latest ranking: 128; Ranking five years ago: 131; Five-year index movement: 3.8%. Here: A supporter of Ivory Coast president Alassane Ouattara campaigns in a market in the city’s Koumassi quarter. (Photo by Sia Kambou/AFP Photo)

A man stands in front of a display with an artificial coral inside the Davos Congress Center at the eve of the annual meeting of the World Economic Forum in Davos, Switzerland, Sunday, January 15, 2023. The site specific data sculpture by media artist Refik Anadol based on approximately one billion coral images processed by machine learning classification models. The annual meeting of the World Economic Forum is taking place in Davos from Jan. 16 until Jan. 20, 2023. (Photo by Markus Schreiber/AP Photo)

“Jason deCaires Taylor is an English sculptor specialising in the creation of contemporary underwater sculptures which over time develop into artificial coral reefs. Taylor integrates his skills as a conservationist, underwater photographer and scuba diving instructor to produce unique installations that encourage the habitation and growth of corals and marine life”. – Wikipedia. Photo: “The Silent Evolution”. Underwater Sculpture, Museo Subacuático de Arte, Cancun. (Photo by Jason deCaires Taylor/UnderwaterSculpture)

Wildlife are hunted down for consumption or for sale in the India eastern state of Nagaland. Hunters can make a good living, with some bred for food or to be sold as pets. These baby parrots, photographed by Caisii Mao via Sipa USA, are seen after they were caught and preserved by a local hunter and for sale at a private residence in Dimapur, India north eastern state of Nagaland on Wednesday, July 24, 2013. (Photo by Caisii Mao/NurPhoto/Sipa USA)

Participants climb a 10km muddy obstacle course during the “Run Mud” race, on March 29, 2019 in the Israeli mediterranean coastal city of Tel Aviv. Over 6,000 participants took part in the obstacle race, with up to 18 artificial obstacles on three tracks (10 km, five km or two km). (Photo by Jack Guez/AFP Photo)