“Slow”. A calm cow in the messy streets of Jodhpur. Photo location: India. (Photo and caption by Matthias Troeger/National Geographic Photo Contest)

An Iraqi woman and foreigners use pair of compact discs as a filter to watch the partial solar eclipse in war-torn Baghdad, 29 March 2006. Without access to proper equipment to protect their eyes from the sun's rays, eclipse watchers in Iraq used makeshift filters. The moon blotted out the sun over northwest Africa early Wednesday, turning day into night in a total solar eclipse as it swept a shadowy path from the outer tip of Brazil to the steppes of Mongolia. (Photo by Hassan Ammar/AFP Photo)

Seized plastic handguns which were created using 3D printing technology are displayed at Kanagawa police station in Yokohama, south of Tokyo, in this photo taken by Kyodo May 8, 2014. Yoshimoto Imura became the first man to be arrested in Japan for illegal possession of two guns he created himself using 3D printing technology, Japanese media said on Thursday. The 27-year-old, a college employee in the city of Kawasaki, was arrested after police found video online posted by Imura claiming to have produced his own guns. Gun possession is strictly regulated in Japan. Police raided Imura's home and found five guns, two of which could fire real bullets, Japanese media said. (Photo by Reuters/Kyodo)

In this photo taken on Thursday, July 23, 2015 migrants enter a train to Serbia at the railway station in the southern Macedonian town of Gevgelija. The country has become a major transit route for thousands of Middle Eastern and African refugees and migrants who cross over from Greece and then continue into Serbia. (Photo by Boris Grdanoski/AP Photo)

Women jump into the water during a traditional New Year bath in the Adriatic sea in Portoroz, Slovenia on January 1, 2018. (Photo by Jure Makovec/AFP Photo)

A participant poses for a photograph at the annual Easter Parade and Bonnet Festival in the Manhattan borough of New York City, New York, U.S. on April 1, 2018. (Photo by Gaia Squarci/Reuters)

Owners and their dogs take part in “HK Doggie Dash 2018”, an event held to raise money for for abandoned and surrendered dogs in Hong Kong on April 15, 2018. Dozens of pugs and dachshunds compensated for their modest speed with peppy spirits at Hong Kong’s inaugural “doggie dash” on April 15 that raised funds and awareness for the city’s abandoned and rescued dogs. (Photo by Isaac Lawrence/AFP Photo)

A unidentified woman protests at Broad Street for the pending arrival of Vice President Mike Pence at the Union League, in Philadelphia, Monday, July 23, 2018. Dozens of demonstrators dressed as characters from the novel-turned-TV series “The Handmaid's Tale” descended on downtown Philadelphia to protest Pence’s visit. (Photo by Jose F. Moreno/The Philadelphia Inquirer via AP Photo)