Ammunition airlift into besieged Khe Sanh, Operation Pegasus, April 1968. (Photo by Larry Burrows/AP Photo)

The National Geographic Photo Ark is a travelling exhibition of photographer Joel Sartore’s quest to create a photo archive of biodiversity around the world. So far, Sartore has captured studio portraits of more than 6,000 species – a number that he hopes to double. On 1 July, the ark will open at Melbourne zoo – the first time it has been exhibited in the southern hemisphere. More than 50 portraits will be on display, including many of Australian endangered animals being protected by programs at the zoo itself. These captions have been edited from text supplied by Melbourne zoo. Here: Barking owl. (Photo by Joel Sartore/National Geographic Photo Ark/The Guardian)

A wide-angle view shows the ascent of the shuttle Challenger on January 28, 1986. In the seconds after ignition, the rocket engines' hot blast began the process of destruction. (Photo by NASA)

An African giant pouched rat sniffs for traces of landmine explosives at APOPO's training facility in Morogoro on June 17, 2016. APOPO trains the rats to detect both tuberculosis and landmines at its facility. Every year landmines kill or maim thousands of people worldwide. The trained rats sniff for explosive and so are able to detect the presence of landmines far faster than conventional methods which involve metal detection. (Photo by Carl De Souza/AFP Photo)

An art wall painting representing performance artist Marina Abramovic by Italian artist Maurizio Cattellan to publicize his upcoming exhibition The Artist is Present, in Shanghai, China, is displayed on a facade of a building, in Milan, Italy, Wednesday, September 19, 2018. (Photo by Luca Bruno/AP Photo)

Seattle Mariners center fielder Julio Rodríguez laughs as teammate Teoscar Hernández douses him as they celebrate a 9-2 win over the Baltimore Orioles in a baseball game Friday, August 11, 2023, in Seattle. (Photo by Lindsey Wasson/AP Photo)

Supporters of presidential candidate Gustavo Petro, with the Historical Pact coalition, celebrate after his candidate won a presidential runoff in Bogota, Colombia, Sunday, June 19, 2022. (Photo by Fernando Vergara/AP Photo)

Rows of workers shelter under umbrellas from the scorching heat as they painstakingly sort through a red carpet of millions of chilli peppers in Bogra, Bangladesh on October 3, 2023. They sort the rotten and broken chilli peppers out to separate the poor quality ones which won't sell. In a line, the pickers who are paid less than £3 for a 10-hour shift slowly move forward with their baskets to separate the bad from the good after the chilies have been dried in the sun for a week. (Photo by Joy Saha/Rex Features/Shutterstock)