Tourists ice skate at night on the Eiffel Tower's skating rink in Paris December 9, 2014. The skating rink, located on the first level of the Eiffel Tower, opens to the public as part of the Christmas holiday season. (Photo by Charles Platiau/Reuters)

“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)

“Say cheese”. Cheetahs jumped on the vehicle of tourists in Masai Mara national park, Kenya. (Photo and caption by Yanai Bonneh/National Geographic Traveler Photo Contest)

ATTENTION! All pictures are presented in high resolution. To see Hi-Res images – just TWICE click on any picture. In other words, click small picture – opens the BIG picture. Click BIG picture – opens VERY BIG picture.

A tattoo of Captain America drawn by artist Sean Karon on the leg of client Ron Raucci at the Hampton Roads Tattoo Festival in Virginia, on March 2, 2012. The tattoo was completed from start to finish in one five-and-a-half hour session and won the prestigious “tattoo of the day” contest. (Photo by Jason Reed/Reuters)

A biker shows his 12-year-old cat “Chiquinho” – which always rides with him on his motorbike – in Rio de Janeiro, Brazil, on June 19, 2016. (Photo by Yasuyoshi Chiba/AFP Photo)

The Rio de Janeiro Olympics kick off on August 5 for some two weeks of competitive games drawing athletes as well as audiences from around the world. As they prepare to cover the event, Reuters photographers look back on their favourite pictures from past Olympics where they captured the action on the ground as well as the participants' tears and joy that followed. (Photo by Lucy Nicholson/Reuters)

Praia du Forte, Bahia. “This was the lead picture for a National Geographic story on Bahia, because it was both mysterious as well as a “geography” picture showing where the slaves arrived from Nigeria. Beach pictures seem like they should be easy to take, but for me they are actually quite difficult. Too easy to fall into cliche. When I saw the kid coming on the horse, I quickly ran to see if I could make something with a woman in a bikini that was not a bikini shot”. (Photo by David Alan Harvey/The Guardian)

Blankets cover the bodies of a woman (right) and a man (left background) hit by a northbound Penn Central train (background) as they waited with a crowd at Pennsylvania Railroad station in Elizabeth, N.J. on June 8, 1968 to view the southbound train carrying the body of Sen. Robert F. Kennedy to Washington. The woman was identified as Mrs. Antoinette Severini, 54, and the man, John Curia (age unavailable), both of Elizabeth. (Photo by AP Photo)