“Hippo Chase”. As we approached the camp the Selinda Reserve of northern Botswana our boat passed by a hippo resting in the water. I turned around to look back at the boat's wake and saw the hippo charging after us! The hippo must've been tired from an all-nighter because he was angry. He rose way up out of the water three times trying to chase our boat! He was coming at us with such force that he created a wake of his own. Photo location: Selinda Reserve of northern Botswana. (Photo and caption by Curtis Simmons/National Geographic Photo Contest)

New autopilot features are demonstrated in a Tesla Model S during a Tesla event in Palo Alto, California, 2015. Federal officials say the driver of a Tesla S sports car using the vehicle’s “autopilot” automated driving system has been killed in a collision with a truck, the first U.S. self-driving car fatality. The National Highway Traffic Safety Administration said preliminary reports indicate the crash occurred when a tractor-trailer made a left turn in front of the Tesla at a highway intersection. Joshua D. Brown, of Canton, Ohio, died in the accident May 7 in Williston, Florida, when his car's cameras failed to distinguish the white side of a turning tractor-trailer from a brightly lit sky and didn't automatically activate its brakes, according to government records obtained Thursday. (Photo by Beck Diefenbach/Reuters)

A man takes a photo of a radio antenna that's part of the Atacama Large Milimeter Array Observatory on March 12, 2013 at Llano de Chajnantor, about 43 miles (70 kilometers) from San Pedro de Atacama, Chile. The $1.5 billion ALMA facility, which had its official inauguration on March 13, is considered the world's most expensive ground-based observatory. (Photo by Felipe Trueba/EPA)

The November 2018 Square Print Sale, presented by Magnum Photos and Aperture, brings together over 100 images to explore perspectives on transition and transformation in photography. Here: New York City, 1965, by Joel Meyerowitz. “A girl on a Vespa on her way to who knows where, when the light stopped her at the 72nd street crossing near the Dakota, where John Lennon would one day cross paths with his fate. She takes this moment to finesse a fingernail before she resumes her downtown journey, while I, stopping at the same crossing, but on foot, leap into the street to capture this vision of a dream girl before time takes her on her way”. (Photo by Joel Meyerowitz/Courtesy Aperture)

In a photo taken on September 11, 2019, North Korean students pose for photos in Chonji lake, or “Heaven lake”, as they visit the crater of Mount Paektu, near Samjiyon. Mount Paektu has long been considered the spiritual birthplace of the Korean nation and is a place of pilgrimage for tens of thousands of North Koreans every year, who are trained from birth to revere their leaders. (Photo by Ed Jones/AFP Photo)

Tandem hair drying is possible with a new two-hood attachment for any electric hair dryer manufactured by Postcraft Co of Tucson, Ariz., shown in Chicago, January 27, 1965. A Y adapter permits two hoses to be attached to the dryer. (Photo by Edward Kitch/AP Photo)

This image made available by the Johns Hopkins University Applied Physics Laboratory on Wednesday, May 31, 2017 depicts NASA's Solar Probe Plus spacecraft approaching the sun. On Wednesday, NASA announced it will launch the probe in summer 2018 to explore the solar atmosphere. It will be subjected to brutal heat and radiation like no other man-made structure before. (Photo by Johns Hopkins University Applied Physics Laboratory via AP Photo)

Lightning strikes during a storm over the Ionian Sea in Calabria, Italy on June 27, 2016. (Photo by Alfonso Di Vincenzo/Pacific Press/Rex Features)