A murmuration of starlings above the the small village of Rigg, near Gretna, in the Scottish Borders, on November 25, 2013. The weight of the resting birds on power lines caused some power localised power outages in the village. Still one of the commonest of garden birds, its decline elsewhere puts it on the Red List of endangered species. (Photo by Owen Humphreys/PA Wire)

Central Palo Seco power station of the Puerto Rico Electric Power Authority (PREPA) is seen behind a cemetery, in San Juan, Puerto Rico on January 22, 2018. (Photo by Alvin Baez/Reuters)

A general view shows the Krasnoyarsk hydro-electric power station on the Yenisei River near the Siberian city of Krasnoyarsk, Russia, January 13, 2016. The power plant, owned by EuroSibEnergo company, part of En+ Group, with a generating capacity of 6,000 megawatt (MW), has a ferro-concrete dam 124-metres high and 1065-metres long and is the second largest Russian hydroelectric power station. About 85% of the energy generated is intended for the Rusal Krasnoyarsk aluminium smelter, according to representatives of the power station. (Photo by Ilya Naymushin/Reuters)

Passengers travel on the London train and underground system during the Christmas party season, December 18, 2015. (Photo by Paul Hackett/Reuters)

A ballet student poses for a friend to take photos, at the national ballet school in Havana, Cuba, Thursday, December 12, 2019. The Soviet-style system that recruits children into a system of increasingly selective state dance schools has produced hundreds of elite dancers including Lorna Feijoo, Rolando Sarabia, Taras Domitro, Anette Delgado and Carlos Acosta. (Photo by Ramon Espinosa/AP Photo)

Engineer Mikhail Venin works on an antenna for the Express AM8 new generation geostationary telecommunications heavy satellite at the large-sized transformed mechanical systems centre of the Reshetnev Information Satellite Systems company in the Siberian town of Zheleznogorsk April 2, 2014. The Express AM6 is a new generation satellite providing services including Russian governmental and presidential mobile communication, digital television and broadcasting, according to the Reshetnev company representatives. (Photo by Ilya Naymushin/Reuters)

The possible surface of TRAPPIST-1f, one of seven newly discovered planets in the TRAPPIST-1 system that scientists using the Spitzer Space Telescope and ground based telescopes have discovered. (Photo by Reuters/NASA/JPL-Caltech)