Two robotic legged squad support system (LS3) machines by the Defense Advanced Research Project Agency follow a technician during a demonstration at Joint Base Myer-Henderson Hall, Virginia, on September 10, 2012. (U.S. Marine Corps photo by Sgt. Mallory S. VanderSchans via The Atlantic)

“Double head vulture”. On the day of windy days during raptors migration some people in my country start to catch these tired raptors, so in this day we go to photograph some raptors and we saw these tow tired vultures, so we start to drag them away from the hunters until they reach a good hidden place, to make them safe until they start a new journey. Photo location: Kuwait. (Photo and caption by Mohd Khorshed/National Geographic Photo Contest)

Handout grab taken from YouTube of Commander Chris Hadfield who has said goodbye to life on the International Space Station by making a cover version of David Bowie's Space Oddity. Issue date: Monday May 13, 2013. (Photo by Commander Chris Hadfield/YouTube/PA Wire)

“The Baja California Pronghorn or Peninsular Pronghorn (Antilocapra americana peninsularis) is a critically endangered pronghorn, endemic to Mexico. The wild population is estimated at 200”. – Wikipedia

Photo: Two rare Peninsular pronghorns, male twins was born at the Los Angeles Zoo on April 24, 2009 in Los Angeles, California. Only 250 antelope-like Peninsular pronghorns are believed to exist in the wild. (Photo by David McNew/Getty Images)

In this November 9, 2014 photo, a man sits on the rope holding his bull by the neck as he waits to enter it in a bull fight in Leogane, Haiti. The obscure Haitian practice of fighting bulls is brutal like a cock or dog fight, but on a larger scale. A casual pastime for some rural men, it is serious business for others looking to pay their children's school fees or even buy a car. (Photo by Dieu Nalio Chery/AP Photo)

Artist Vik Muniz is known for his gigantic composite installations and sculptures created from thousands of individual objects. In this new collaboration with artist and MIT researcher Marcelo Coelho, Muniz takes the opposite approach and explores the microscopic with a new series of sandcastles etched onto individual grains of sand.

Gray whale feeding at the surface and showing it's baleen. (Photo by Christopher Swann/Biosphoto)

Shortlisted: “Two big eyes” by Miao Yong (Zejiang province, China). Damselflies look over the leaves. “I was photographing insects in a park near my home when suddenly I found two damselflies in the grass. They kept flying and it was very difficult to focus until suddenly they parked behind a leaf”. (Photo by Miao Yong/2017 Royal Society of Biology Photographer of the Year)