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)

The second and final qualification motor (QM-2) test for the Space Launch System's booster, June 28, 2016, at Orbital ATK Propulsion Systems test facilities in Promontory, Utah. During the Space Launch System flight the boosters will provide more than 75 percent of the thrust needed to escape the gravitational pull of the Earth, the first step on NASA's Journey to Mars. (Photo by Bill Ingalls/NASA)

Joseph Szabo was a frustrated high-school teacher in need of inspiration – so he started photographing his students, and captured all the angst and excitement of being caught between childhood and adulthood. Here: “Priscilla”, 1969. (Photo by Joseph Szabo/Courtesy of Michael Hoppen Gallery/The Guardian)

Models in lingerie are seen walking the streets of Sydney during a marketing campaign in support of marriage equality in Sydney, Australia on August 14, 2017. On Monday, 60 Honey Birdette employees took to the streets of the Sydney CBD in support for marriage equality ahead of the federal government’s controversial postal plebiscite on the topic, with forms slated to arrive in Australians’ mailboxes on September 12. Australians will vote on whether to legalise gay marriage via a voluntary postal vote and need to register by August 24. According to Honey Birdette’s Facebook page, the aim of the demonstration was to empower women and celebrate equality. The founder and CEO of the brand Eloise Monaghan is a “proud member of the community” and married to another woman. (Photo by PA Wire)

In this undated handout photo taken by mrwed54, a woman poses for a photo by a lake in the Siberian city of Novosibirsk, about 2,800 kilometers (1,750 miles) east of Moscow, Russia. Thousands of Novosibirsk residents, from scantily clad women to newlyweds have been instagramming selfies near the lake nicknamed the “Siberian Malvides” after the far-flung tropical islands in the Indian Ocean. This is in fact is a man-made dumb of coal from a nearby power station that provides for most of Novosibirsk’s energy needs. Environmentalists are warning people against coming into contact with the water. (Photo by mrwed54 via AP Photo)

Visitors look at a plastinated gorilla on the opening day at the Body World Animals exhibition at the Cologne Zoo on April 15, 2011 in Cologne, Germany. The exhibition is by Gunther von Hagens, who uses a special process to preserve real bodies, whether animal or human, in order to display the inner organs, muscles and other physical elements. The exhibition will be open to the public until September 30.

Jordanian policewomen train in unarmed combat in the training city August 21, 2008 in Muwaqqar, east of Amman, Jordan. A women's police academy opened in Amman in 1972 making Jordan the first Arab country to admit women to its police services. Jordanian policewomen work as personalities' guards, special security operations and traffic policewomen including motorcycling among other professions. (Photo by Salah Malkawi/Getty Images)