A man rides a horse at a playground on a hill in Kabul April 19, 2015. (Photo by Mohammad Ismail/Reuters)

A walruses at Hagenbeck Zoo in Hamburg, Germany on July, 7, 2015. (Photo by Werner Struss/Startraks action)

A runner in fancy dress participates in the Virgin London Marathon 2013 on April 21, 2013 in London, England. (Photo by Tom Dulat/Getty Images)

“The scientists behind NASA's $2.5 billion Curiosity rover mission on Mars on Tuesday explained the nature of a tiny, gleaming "flower" embedded in Red Planet rock, and revealed where they'll be using the SUV-sized robot's drill for the first time”. – Alan Boyle via NBCNews.com

Photo: Scientists say that a “Martian flower”, seen here in an image from the Curiosity rover's Mars Hand Lens Imager, is a 2-millimeter-wide grain or pebble that's embedded in the surrounding rock. Another, darker-colored mineral grain can be seen above and to the left. (Photo by NASA)

This 1999 photo, supplied by HBO, shows a younger-looking James Gandolfini, who plays mob boss Tony Soprano, in an episode from the first season of the HBO cable television mob series, “The Sopranos”. Actor James Gandolfini, best known for his Emmy-winning portrayal of a conflicted New Jersey mob boss in the acclaimed HBO cable television series “The Sopranos”, has died while vacationing in Rome, the network said on June 19, 2013. (Photo by Anthony Neste/AP Photo/HBO)

Sea of clouds is seen after a rainfall at the Huangshan Mountain scenic spot on April 10, 2019 in Huangshan, Anhui Province of China. (Photo by Fang Lihua/Qianlong.com/VCG via Getty Images)

Actress Demi Moore attends Irving “Swifty” Lazar's Oscar Party hosted at Spago on March 29, 1989 in West Hollywood, California. (Photo by Jim Smeal/WireImage)

Astronaut Donald R. Pettit would often rig an array of as many as six cameras in the cupola windows and set them all to fire continuously for events such as sunsets, which only last around seven seconds on the ISS. (Photo by Donald R. Pettit)