A model backstagee is pictured before the Philipp Plein Spring/Summer 2016 collection during Milan Fashion Week in Italy September 23, 2015. (Photo by Alessandro Garofalo/Reuters)

An unknown number of guns are being built with the mechanisms, causing problems for the police and ATF officials. Photo: An ATF agent holds a generic unfinished receiver, back, and one that has been manufactured, front, at an ATF field office in Washington, on May 06, 2014. The ATF is trying to crack down on the trade in the makeshift guns by targeting shops and individuals who offer to turn the unfinished receivers into functional pieces for firearms. (Photo by Bill O'Leary/The Washington Post)

“What created this unusual hole in Mars? The hole was discovered by chance on images of the dusty slopes of Mars' Pavonis Mons volcano taken by the HiRISE instrument aboard the robotic Mars Reconnaissance Orbiter currently circling Mars”. (Photo by NASA/JPL/University of Arizona)

A woman cries after a supporter of opposition leader Raila Odinga was killed by police, witnesses said, in Mathare slum in Nairobi, Kenya August 9, 2017. (Photo by Goran Tomasevic/Reuters)

Colombian Jahn Fredy Duque, dressed as superhero “Spiderman”, performs on the streets in Bogota, Colombia on April 24, 2017. Duque hangs a white cloth 26 meters long – his cobweb – from a bridge near the international center of Bogota, where he performs in the street for a livelihood. (Photo by Raul Arboleda/AFP Photo)

In this Monday, January 18, 2016 photo, Iranian rock climber, Farnaz Esmaeilzadeh, scales a climbing gym in the city of Zanjan, some 330 kilometers (207 miles) west of the capital Tehran, Iran. Esmaeilzadeh, 27, who has been climbing since she was 13, has distinguished herself in international competitions despite the barriers she faces as a female athlete in conservative Iran. (Photo by Ebrahim Noroozi/AP Photo)

Google has built its first self-driving car prototypes and hopes to test hundreds more models this summer. If all goes well, the company is planning a pilot program in California over the next few years.

A dog known as “Menswear Dog”, a 5-year-old Shiba Inu, poses for photos during the 24th Annual Tompkins Square Halloween Dog Parade in New York October 25, 2014. Hundreds of dog owners dress their dogs and compete for fun and prizes during the parade. (Photo by Carlo Allegri/Reuters)