ESA astronaut Samantha Cristoforetti on the International Space Station 3 February 2015 during her Futura mission. Samantha is living and working on the Station as part of the Expedition 42 crew. Picture released on February 10, 2015. (Photo by ESA/NASA)

In this April 2, 2015 photo, dog owner Laura Aquilina strolls with her two year old Rottweiler Brutus, who was recently fitted with prosthetics on all four paws, and is currently learning to use them, near Aquilina's home in Loveland, Colo. Brutus lost all four paws to frostbite as a puppy while under care of a breeder, and Aquilina began caring for him about a year ago. (Photo by Brennan Linsley/AP Photo)

These stunning pictures show a normally vicious tiger calmly swimming in a pool of algae, on Jule 9, 2014. The powerful cat takes a refreshing break by taking a dip in the bright green algae. But it looks like this big cat is scared of getting his head wet as he strains to keep it above the water. After splashing around for a bit the tiger gets out and tries to air-dry with specks of the vegetation dripping off his fur. The striking pictures were taken at Copenhagen zoo by snapper Soren Lundgren Neilson. (Photo by Soren Nielsen/Caters News)

“The Sunsetter”. An EF-4 tornado rips through the open space of farmland near Rozel, Kansas. This tornado moves slowly but powerful towards the setting sun an gets its beautiful color right before sunset. Storm Chasers are spotting on the left side. Photo location: Rozel, Kansas. (Photo and caption by Dennis Oswald/National Geographic 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.

“People and Space”. Winner: Wanderer in Patagonia by Yuri Zvezdny (Russia) A lone stargazer stares up at the stars of our galaxy, the Milky Way, as they stretch across the night sky over the glacier “White Stones” (Piedras Blancas) in the Los Glaciares National Park, Argentina. El Chaltén, Santa Cruz Province, Argentina, 27 September 2016 iOptron Sky-Tracker mount, Sony A7S camera, 18 mm f/2.8 lens, ISO 5000, 30-second exposure Wanderer in Patagonia. (Photo by Yuri Zvezdny/Insight Astronomy Photographer of the Year 2017)

Baloo (R), a North American Black Bear, rubs snouts with his companion Shere Hkhan, a Bengal tiger, inside their shared enclosure at Noah's Ark animal sanctuary in Locust Grove, Georgia, USA, 28 August 2014. According to the facility, the pair and a lion named Leo, were confiscated at a young age from a drug dealer's basement in Atlanta, Georgia. Noah's Ark cares for about 100 different species of animals on a 250 acre farm since 1990. (Photo by Erik S. Lesser/EPA)

“Locusts & Men”. Oppression, interaction, collaboration. In the life cycle of nature nothing is lost, but the coexistence of different species is sometimes difficult. In Madagascar periodically returns the archaic antagonism between man and the migratory locust, in a circle of life where the two species are looking for space and food for their survival. At the end of the day a man walks home carrying on his shoulders the heavy bag which contains the locusts captured during the day. The insects provide nutritious meals for the man and his family. Photo location: Madagascar, 2013. (Photo and caption by Michele Martinelli/National Geographic 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.

“Aurora over a glacier lagoon”. A vivid green overheaded aurrora pictured in Iceland's Vatnajokull National Park reflected almost symetrically in Jokulsrlon Glacier lagoon. A complete lack of wind and currrent combin in this sheltred lagoon scene to crete an arresting mirror effect giving the image a sensation of utter stillness. Despite theis there is motion on a suprising scale, as the loops and arcs of the aurora are shaped by the shifting forces of the Earth's magnetic field. James Woodend of Great Britain won the grand prize with the image, beating out more than 2,500 other entries. The Astronomy Photographer of the Year 2014 contest is judged by the Royal Observatory Greenwich and BBC Sky at Night magazine. (Photo by James Woodend/The Astronomy Photographer of the Year 2014 Contest)