The annual Antarctic photography exhibition, which is part of Hobart’s Antarctica festival is back on with its chilly, majestic imagery. The winner this year is Sydney’s Sam Edmonds with his striking photo of a gentoo penguin in the snow. Here: Casey Station 2017. (Photo by Chris J. Wilson/The Guardian)

Soviet Army soldiers sit on their tanks in front of the Czechoslovak Radio station building in central Prague during the first day of Soviet-led invasion to then Czechoslovakia on August 21, 1968. (Photo by Libor Hajsky/Reuters)

In this March 7, 1991 file photo, a U.S. Marine patrol walks across the charred oil landscape near a burning well during perimeter security patrol near Kuwait City. Twenty five years after the first U.S. Marines swept across the border into Kuwait in the 1991 Gulf War, American forces find themselves battling the extremist Islamic State group, born out of al-Qaida, in the splintered territories of Iraq and Syria. The Arab allies that joined the 1991 coalition are fighting their own conflicts both at home and abroad, as Iran vies for greater regional power following a nuclear deal with world powers. (Photo by John Gaps III/AP Photo)

Women walk through the snow on Wimbledon common with their dogs on February 10, 2012 in London, England. The Met Office cold weather alert remains at Level 3 as southern parts of England continue to suffer from cold weather and freezing conditions, with further snowfall overnight. (Photo by Peter Macdiarmid/Getty Images)

Actors from the Israeli theatre group Orto-Da perform during their show titled “Stones”, at a theatre in Tel Aviv March 10, 2015. Inspired by Nathan Rapoport's Warsaw Ghetto Uprising Monument, the play tells a story from the point of view of the sculptures in the monument. (Photo by Amir Cohen/Reuters)

A view of an entrance to the concrete case surrounding the pressure vessel of the reactor is seen inside the decommissioned Unit Six of the Greifswald nuclear power station outside Lubmin August 5, 2014. Unit Six was a part of East Germany's largest nuclear power plant that was nearly completed in 1990, when the country's re-unification halted construction. (Photo by Thomas Peter/Reuters)

People wearing loin cloths pray after they bathe in ice-cold water outside the Teppozu Inari shrine in Tokyo, Japan, January 8, 2017. (Photo by Toru Hanai/Reuters)

Ice covered leafs are pictured on a tree near Amstall in northern Austria, December 2, 2014. Freezing fog and rain covered parts of the region with ice, causing blocked roads due to fallen trees and closed schools for security reasons, local media report. (Photo by Heinz-Peter Bader/Reuters)