Photographer and animal lover Chris Keeney shows how to use a PetCam with your own pet and offers expert technical know-how and inspiring creative suggestions to get you started. This is Coulee, a border collie/golden retriver mix from Lethbridge, Alberta, Canada. (Photo by Chris Keeney/Princeton Architectural Press)

A coil-shaped Helix Nebula showing a fine web of filamentary “bicycle-spoke” features embedded in the colorful red and blue ring of gas. At 650 light-years away, the Helix is one of the nearest planetary nebulae to Earth. A planetary nebula is the glowing gas around a dying, Sun-like star. (Photo by Reuters/NASA)

Ludivine Sagna walks the runway and wears a chocolate costume made by designer and a chocolate maker during the Fashion Chocolate show at Salon du Chocolat at Parc des Expositions Porte de Versailles in Paris, France, October 28, 2014. (Photo by LAURENTVU/SIPA Press)

David Bowie, 1974. David Bowie's quirky character and style was perfectly encapsulated in this shot by Terry O'Neill, which shows the music legend posing next to a barking dog on the artwork for his 1974 album “Diamond Dogs” in London. (Photo by Terry O'Neill)

“These photographs show the food chain in action as a hungry lion braved a river full of crocodiles to try and sink his teeth into a dead hippo. The photos were taken in the Maasi Mara nature reserve, in Kenya and show hungry lion braving a crocodile-infested river to get to an upside down hippo, which had died overnight of natural causes”. – Caters News. (Photo by Richard Chew/Caters News)

A model has makeup applied backstage prior to Lebanese designer Zuhair Murad fashion show held during the Haute Couture Fall/Winter 2014-2015 fashion collections in Paris July 10, 2014. (Photo by Philippe Wojazer/Reuters)

These rare photos capture the Flight Deck (cockpit) of the Space Shuttle Endeavour, fully powered for one of the final times. Just a few weeks later, at 9:58am EDT on May 11, Endeavour was powered down for the final time in history. It was the last of the three space shuttles to have power. Below, other views show the mid-deck, gutted of its lockers and storage areas, and three final photos show the white room entrance in the Orbiter Processing Facility, signed by thousands over the years.

A lithographic sketch, purportedly by Beatles star John Lennon, shows his wife Yoko Ono in a sexual context within a document released by The National Archives March 23, 2004 in London. The document, which has been classified since 1970, contains sketches and letters which were seized by police to form part of the evidence for the indecency trial against the London Art Gallery which had been displaying the material. (Photo by Ian Waldie/Getty Images)