Indian models showcase creations by designer Shivan & Naresh during the Lakme Fashion Week (LFW) Winter/Festive 2016 in Mumbai on August 27, 2016. (Photo by Sujit Jaiswal/AFP Photo)

Young revelers take part in a parade called "La Calabiuza" on November 1, 2015, on the eve of the Day of the Dead in Tonacatepeque, 20 kms (13 miles) north of San Salvador. During the celebration, the residents of Tonacatepeque, originally an indigenous community, recall the characters from the mythology of Cuscatlan – pre-Columbian west and central regions of El Salvador – and their dead relatives. (Photo by Marvin Recinos/AFP Photo)

Netapp Endura team rider Slovenian Blaz Jarc (R) crashes into Katusha team rider Russian Viacheslav Kuznetsov (ground) during the 112th Paris Roubaix cycling race, in Roubaix, France, 13 April 2014. (Photo by Nicolas Bouvy/EPA)

A Tibetan mastiff dog is displayed for sale at a mastiff show in Baoding, Hebei province, south of Beijing on March 9, 2013. Fetching prices up to around 750,000 USD, mastiffs have become a prized status-symbol amongst China's wealthy, with rich buyers across the country sending prices skyrocketing. Owners say the mastiffs, descendents of dogs used for hunting by nomadic tribes in central Asia and Tibet are fiercely loyal and protective. Breeders still travel to the Himalayan plateau to collect young puppies, although many are unable to adjust to the low altitudes and die during the journey. (Photo by Ed Jones/AFP Photo)

“The Challenge!” Young boy relishes in a game of tug of war before school. Photo location: Lake Titicaca, Peru. (Photo and caption by Paul Heyman/National Geographic Photo Contest)

A fan watches the group A World Cup match between Mexico and Brazil via a live broadcast at the FIFA Fan Fest in Sao Paulo, Brazil, Tuesday, June 17, 2014. Forget the French manicure. It’s Brazil during World Cup, and women here want to flaunt their love of the national team with wacky nail designs. (Photo by Dario Lopez-Mills/AP Photo)

“NASA's Mars rover Opportunity just celebrated its ninth anniversary on Mars – a mission that was originally meant to last just 90 days...” – The Atlantic. Photo: NASA's rover Opportunity visits Victoria Crater, viewed from orbit by the High Resolution Imaging Science Experiment on NASA's Mars Reconnaissance Orbiter in october of 2006. Opportunity is a small dot on the crater's lip, at top right. Opportunity first reached the crater's rim on September 27, 2006. (Photo by NASA/JPL-Caltech/University of Arizona via The Atlantic)

Brain-on-a-chip. Dazzling in green and magenta this image shows the nerve fibres (in green) produced by neural stem cells (in magenta) as they grow on a synthetic gel. Captured by a technique known as confocal microscopy, the image is part of research shedding light on how tinkering with the environment can affect the way in which nerve fibres grow. (Photo by Collin Edington and Iris Lee/Massachusetts Institute of Technology/Wellcome Images)