A robot is seen on Mount Etna, Italy on July 4, 2017. Mount Etna, in Sicily, is a test bed for the approximately three-foot high, four-wheeled machine ahead of a future mission to the moon. It is being conducted by the German Aerospace Centre, the agency which runs Germany's space programme. (Photo by Antonio Parrinello/Reuters)

A grey whale greets tourists in boat in, Baja California, Mexico, March 2017. A pair of newly born grey whale calves intrigued by visiting tourists eagerly swim over to the group to get a closer look. Urged on by their mother, the small calves confidently went up to the tour group who were visiting San Ignacio Lagoon in Baja California, Mexico. This adorable moment was captured by zoologist and wildlife photographer, Mark Carwardine on his visit to the area in March 2017. (Photo by Mark Carwardine/Barcroft Images)

Kourtney Roy makes eerie self-portraits in desolate yet dramatic locations – with wigs and wardrobe straight out of 1950s melodrama. In these shots, from her “Enter as Fiction – California” series, she plays characters caught in desolate, often abandoned settings. (Photo by Kourtney Roy/Galerie Catherine et André Hug/The Guardian)

Two Bunny Girls from the Playboy Club and two Penthouse Pets from the Penthouse Club prepare to take part in the annual Good Friday waiters and waitresses race in Battersea Festival Gardens, London, 28th March 1972. (Photo by Ian Showell/Keystone/Hulton Archive/Getty Images)

A photo taken by a member of the County Durham and Darlington fire and rescue Service of a coach on fire on the A1 in County Durham, England on March 2, 2017. Passengers were evacuated safely before flames engulfed the vehicle. (Photo by County Durham and Darlington Fir/PA Wire)

An air tanker drops fire retardant on flames as firefighters continue to battle against the Detwiler fire in Mariposa, California on July 19, 2017. The Detwiler fire is currently at 7 percent containment and has burned more than 45,000 acres and destroyed eight structures. (Photo by Josh Edelson/AFP Photo)

Full-time feline photographer Andrew Marttila from Washington, D.C., captured blissful expressions of various cats on catnip, which he used to compile a book, “Cats on Catnip”. The photographer dedicated his time to capturing the euphoric expressions of kitties high on catnip – and the results are absolutely hilarious. (Photo by Andrew Marttila/Caters News Agency)

“These incredible shots show the stunning formations of an iceberg beneath the surface of the ocean. Taken in Tasiilaq, Greenland, by Franco Banfi, the underwater photography captures the beauty of these ice mountains beneath the ocean’s surface. In some of the photos, divers are swimming around an iceberg under the frozen water, while other images show some of the weird and wonderful creatures you can encounter in that part of the ocean”. (Photo by Franco Banfi/Caters News Agency)