A person dressed as an astronaut walks past a man stopping traffic on a pedestrian crossing outside the Sydney Exhibition Centre September 13, 2014 where the science-fiction convention called “Oz Comic-Con” is currently being held. The two-day convention showcases “pop culture”, and includes appearances by actors from science-fiction movies and television shows. (Photo by David Gray/Reuters)

Palestinian female Hamas security officers demonstrate their skills during a graduation ceremony in the northern Gaza Strip, Wednesday, April 2, 2014. 1200 officers graduated from advanced training courses that lasted one year in Gaza police academy of Hamas. (Photo by Adel Hana/AP Photo)

An Amur tiger walks across a passageway after a news conference at the Philadelphia Zoo, Wednesday, May 7, 2014, in Philadelphia. The see-through mesh pathway called Big Cat Crossing is part of a national trend called animal rotation that zoos use to enrich the experience of both creatures and guests. (Photo by Matt Slocum/AP Photo)

«Mignon 2». A.E.G., Berlin, Germany, 1905. Despite its unusual appearance, the Mignon typewriter is of a very clever design, giving a smooth and fast operation for typing. (Photo and caption by Martin Howard/Martin Howard Collection)

“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)

Catherine, Duchess of Cambridge speaks to soldiers as she arrives at Calgary Airport on July 7, 2011 in Calgary, Canada. (Photo by Chris Jackson/Getty Images)

The overall winner of the 2013 Red Bull Illume photography competition from Lorenz Holder. (Photo by Lorenz Holder/Red Bull)

In this composite image Actress Sophie Marceau has an embarrassing moment as her top falls down while she enters a screening of “Where the Truth Lies” at the Grand Theatre during the 58th International Cannes Film Festival May 13, 2005 in Cannes, France. (Photo by Pascal Le Segretain/Getty Images)