An Afghan man works at a traditional yarn factory in Heart province, Afghanistan July 28, 2015. (Photo by Mohammad Shoib/Reuters)

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)

The competition, which is run by the Royal Observatory Greenwich in association with BBC Sky at Night Magazine, is now in its sixth year and has received over 2,500 entries. Photo: Centre of the Heart Nebula by Ivan Eder (Hungary). Situated 7500 light years away in the “W”-shaped constellation of Cassiopeia, the Heart Nebula is a vast region of glowing gas, energized by a cluster of young stars at its centre. The image depicts the central region, where dust clouds are being eroded and moulded into rugged shapes by the searing cosmic radiation. (Photo by Ivan Eder)

Singer Madonna performs during her concert at the AccorHotels Arena in Paris, France, December 9, 2015, on her Rebel Heart Tour. (Photo by Benoit Tessier/Reuters)

The Britain’s Got Talent host Amanda Holden, 48, showed off her flexibility in knee-high boots in the corridors of Heart FM in London, England on February 3, 2020. (Photo by The Sun)

A couple takes selfie pictures amid heart shaped decorations setted for Valentine's day, in Bangkok, Thailand on February 14, 2021. (Photo by Mladen Antonov/AFP Photo)

A woman carries a heart shaped balloon while sitting with her husband on a motorbike during Valentine's day, in Karachi on February 14, 2021. (Photo by Rizwan Tabassum/AFP Photo)