Soldiers of China's People's Liberation Army (PLA) jump as part of their winter training in temperature of negative 26 degrees Celsius at China's border with Russia in Heihe, Heilongjiang province, December 14, 2015. (Photo by Reuters/Stringer)

Fossil records indicate that this early lizard, Megalania (Megalania prisca or Varanus priscus), was a whopping seven metres in length. They were part of a megafaunal assemblage that inhabited southern Australia during the Pleistocene. The youngest fossil remains date to around 50,000 years ago. The first aboriginal settlers of Australia might have encountered them and been a factor in their extinction. (Photo by Sky TV/The Guardian)

This absolute hero came to the rescue when flash floods in a World Cup city left two women stranded in their submerged cars. Here: A woman is rescued from a car after a flash flood in Nizhny Novgorod, Russia on June 19, 2018. (Photo by Lucy Nicholson/Reuters)

Comic Con fans in costume arrive for the 1st day of the 2018 New York Comic-Con at the Jacob Javits Center on October 4, 2018. The four-day event which runs October 4-7 is the largest pop culture event on the East Coast. (Photo by Timothy A. Clary/AFP Photo)

A cave diver in Anhumas Abyss, Bonito, Brazil. (Photo by Marcio Cabral/Epson International Pano Awards 2018)

Two F-15E Strike Eagles wait to receive fuel from a KC-135R Stratotanker during exercise Red Flag 15-1 on their way to Nellis Air Force Base, Nev., Jauary 23, 2015. The F-15s are assigned to the 4th Fighter Wing. U.S. (Photo by Airman 1st Class Aaron J. Jenne/Reuters)

A rainbow is seen near a cloud south of Corvallis, Ore., Monday, May 19, 2014. (Photo by Andy Cripe/AP Photo/The Corvallis Gazette-Times)

A person takes a picture of the “Temple”, a 21-foot painted bronze sculpture from 2008, by British artist Damien Hirst, as the spread of the coronavirus disease (COVID-19) continues in the Alpine resort of St. Moritz, Switzerland February 25, 2021. (Photo by Arnd Wiegmann/Reuters)