After 12 years photographing models, musicians, and celebrities, Brad Wilson decided that he wanted to photograph something a little more unpredictable: wild animals. Photo: Serval. (Photo by Brad Wilson)

Mr. Zhong Hua, of Johns Hopkins University School of Medicine, took this image of the peripheral nerves (those outside of the brain) in an 11.5-day-old mouse embryo, magnified five times. (Photo by Zhong Hua)

Skeleton involves a person riding a small sled down a frozen track while lying face down. The sport is a more intense form of luge because skeleton competitors leap onto the sled and slide downhill head first. Skeleton athletes can reach up to 80 mph on straightaways, causing forces up to 5g, so the helmet is a critical component for attitude as well as safety.

A dead body is seen on the ground after violence erupted in the Independence Square in Kiev February 20, 2014. Ukrainian protesters seized back Kiev's Independence Square in fresh clashes with riot police on Thursday that left several injured and possibly two demonstrators dead. (Photo by David Mdzinarishvili/Reuters)

Indian paramilitary forces march during the annual Republic Day parade on Rajpath in New Delh, January 26, 2013. Republic Day commemorates the 1950 adoption of India's constitution. (Photo by Kevin Frayer/Associated Press)

It's that time of year again when dogs with unusually large heads, hairless bodies and other oddities compete to be the World's Ugliest Dog. This year's winner? A 2-year-old mutt named Peanut, whose wild white and brown hair, bulging eyes and protruding teeth belie his sweet, energetic personality. Peanut's owner, Holly Chandler of Greenville, North Carolina, says he was seriously burned as a puppy and she wants to use her pet to raise awareness about animal abuse. She plans to use the $1,500 prize to pay for other animals' veterinary bills. The contest, held at the Sonoma-Marin Fairgrounds in Petaluma, California, is in its 26 year. The dogs are scored by a three-judge panel in several categories, including special or unusual attributes, personality and natural ugliness.

The anthropomorphic robot named hitchBOT sits on the shoulder of Highway 102 to begin its 6000 kilometer cross country journey outside of Halifax, Nova Scotia, July 27, 2014. The hitch hiking robot is part of a social experiment to see if drivers will pick up and drop off the robot in one piece to an art gallery in Victoria, British Columbia. (Photo by Paul Darrow/Reuters)

Iraqi army soldiers warm themselves next to a fire near the Qayara air base, south of Mosul, Iraq, Tuesday, November 1, 2016. The U.N. human rights office is lauding efforts by the U.S.-led coalition in the battle against the Islamic State group in Mosul. The office in Geneva says coalition flights over Iraq have largely succeeded in preventing IS from bringing in 25,000 more civilians to the city center, where the militant group has been using people as human shields as Iraqi forces advance on Mosul. (Photo by Felipe Dana/AP Photo)