This is the amazing moment a heroic hippo saved a gnu from certain death. After being bitten by a crocodile, the large antelope is seen being dragged slowly under the water. But in a miraculous turn of events, a nearby hippo is seen making its way across the water to help the animal in its hour of need. Photo: One of the biggest hippos protects the gnu as it makes its way back to the shoreline, guarding it from any further attacks. (Photo by Vadim Onishchenko/Caters News)

Lindsay Heimbach goes airborne while sledding down a hill on Mt. Lemmon December 27, 2008. (Photo by James Gregg/Arizona Daily Star)

“A dazzling exhibition featuring jewelry made with the world’s largest diamond will be part of the celebrations marking the 60th anniversary of Queen Elizabeth II’s reign. The jewelry was made with a 3,106-carat diamond discovered in 1905 at the Cullinan Diamond Mine near Pretoria, the capital of South Africa. The diamond was so large that miners initially thought it was a worthless crystal and almost threw it away”... – Vidya Kauri via News.nationalpost.com

Photo: Caroline de Guitaut, Curator of Royal Collections, holds the Cullinan III and IV Broach and the Cullinan VII Delhi Durbar Necklace and Cullinan Pendant at The Queen's Gallery, Buckingham Palace on May 15, 2012 in London, England. (Photo by Peter Macdiarmid)

Paris-born Polish film maker, Roman Polanski. (Photo by James Jackson/Evening Standard/Getty Images). January 1969

A logometer used to determine the Titanic's speed is seen among artifacts recovered from the RMS Titanic wreck site at a press preview of a Titanic artifact auction at the Intrepid Sea, Air & Space Museum on January 5, 2012 in New York City. On April 11, 2012, the 100th anniversary of the maiden voyage of the Titanic, Guernsey's will auction the complete collection of more than 5,000 artifacts recovered from the Titanic wreck site. (Photo by Mario Tama/Getty Images)

US marines watch the mushroom cloud from an atomic explosion rise above the Yucca flats, Nevada during a US nuclear weapons test. (Photo by Keystone/Getty Images). USA, 1945

International photographic competition, which runs in association with the Royal Botanic Gardens in Kew, London, awards special prize for the best close-up images. Here: Winner – Mayflies by Petar Sabol, Goričan, Croatia. (Photo by Sabol Petar/International Garden Photographer of the Year)

The Historic Photographer of the Year awards celebrate historic places and cultural sites across the globe, from national treasures to hidden gems. Entries were judged on originality, composition and technical proficiency as well as the story that inspired the submission and its historical impact. Here: Overall winner. Mont Saint-Michel by Daniel Burton. (Photo by Daniel Burton/The Guardian)