Coloured X-ray of a barn owl. A physicist has used X-ray to create an extraordinary collection of artwork. Arie van't Riets pictures reveal birds, fish, monkeys and flowers in an incredible new light. The 66-year-old, from Bathmen in the Netherlands, began X-raying flowers as a means to teach radiographers and physicians how the machine worked. But after adding a bit of colour to the pictures, the retired medical physicist realised the potential for an exciting new collection of art. (Photo by Arie van't Riet/Barcroft Media)

“Horst Faas (28 April 1933 – 10 May 2012) was a German photo-journalist and two-time Pulitzer Prize winner. He is best-known for his images of the Vietnam War”. – Wikipedia

Photo: A U.S. crewman runs from a crashed CH-21 Shawnee troop helicopter near the village of Ca Mau in the southern tip of South Vietnam, December 11, 1962. Two helicopters crashed without serious injuries during a government raid on the Viet Cong-infiltrated area. Both helicopters were destroyed to keep them out of enemy hands. (Photo by AP Photo/Horst Faas)

Commended. In late May, about a quarter of a million snow geese arrive from North America to nest on Wrangel Island, in northeastern Russia. They form the world's largest breeding colony of snow geese. Photographer Sergey Gorshkov spent two months on the remote island photographing the unfolding dramas. Arctic foxes take advantage of the abundance of eggs, caching surplus eggs for leaner times. But a goose (here the gander) is easily a match for a fox, which must rely on speed and guile to steal eggs. “The battles were fairly equal”, notes Sergey, “and I only saw a fox succeed in grabbing an egg on a couple of occasions, despite many attempts”. Surprisingly, “the geese lacked any sense of community spirit”, he adds, “and never reacted when a fox harassed a neighboring pair nesting close by”. (Photo by Sergey Gorshkov/Veolia Environnement Wildlife Photographer)

The Invasion. A quiet street in Macau. Modernization around is quickly changing the city, as documented by Paul Tsui. (Photo by Paul Tsui/National Geographic Travel Photographer of the Year Contest)

Best portfolio winner. Roseate Spoonbill, Platalea ajaja, by Petr Bambousek, Czech Republic. (Photo by Petr Bambousek/2018 Bird Photographer of the Year)

Sharafkhaneh port and lake Urmia. Masoud Ghadiri (Iran). The summer Milky Way is very prominent in this photo. On the galaxy zone, Saturn is located besides the Lagoon nebula. On the right of the horizon, you can see the extreme light pollution of Urmia, which is caused by ever-increasing city development. (Photo by Masoud Ghadiri/National Maritime Museum)

Soap Bubble Structures by Kym Cox. Bubbles optimise space and minimise their surface area for a given volume of air. This phenomenon makes them a useful tool in many areas of research, in particular, materials science and “packing” – how things fit together. Bubble walls drain under gravity, thin at the top, thick at the bottom, which interferes with travelling lightwaves to create bands of colour. Black spots show the wall is too thin for interference colours, indicating the bubble is about to burst. (Photo by Kym Cox/2019 Science Photographer of the Year/RPS)

Clearing skies await a tripod-toting photographer looking for a spot to capture the early-morning light at Portland Head Light, Thursday, January 17, 2013, in Cape Elizabeth, Maine. (Photo by Robert F. Bukaty/AP Photo)