Bonbibi, Treehouse Point, Fall City, WA. The Bonbibi is balanced on two steel yokes. The yokes spread out the load and allow for tree growth and movement in the wind. A small deck hangs from the beams below and uses the treehouse itself to shelter guests. (Photo by Pete Nelson)

An adult helps a young girl light a cigarette as a band plays in the background in the village of Vale de Salgueiro, northern Portugal, during the local Kings' Feast Friday, January 5, 2018. The village's Epiphany celebrations, called Kings' Feast, feature a tradition that each year causes an outcry among outsiders: parents encourage their children, some as young as 5, to smoke cigarettes. (Photo by Armando Franca/AP Photo)

In Weronika Gęsicka’s unsettling images, American archive photography gets distorted into scenes that are both nightmarish yet somehow entirely plausible. Gęsicka is a guest artist at the Circulations festival for young European photographers, Paris, until 5 March. Here: “Untitled #5”. (Photo by Weronika Gęsicka/The Guardian)

Aurora Australis from Beerbarrel Beach, by James Stone. Runner Up: Aurorae. (Photo by James Stone/Astronomy Photographer of the Year)

For her series “Dolce Vita in Hell”, Swiss photojournalist Stéphanie Buret headed to Eritrea and found a country struggling to haul itself out of oppression – but with its art deco buildings still looking stunning. (Photo by Stéphanie Buret/The Guardian)

Vanessa, thirty-five, had three children with an abusive husband. She “lost her mind, started doing heroin”, after losing the children, who were taken away and given to her mother. The drugs led to homelessness and prostitution. She grew up on Arthur Avenue in the Bronx, but now spends her time in Hunts Point, “trying to survive everyday. Just doing whatever it takes”.

An elephant bull charges a female hippopotamus as her calf scampers to safety, in Erindi Private Game Reserve in Windhoek, Namibia. (Photo by Rian van Schalkwyk/Barcroft Media)

“A meteor streaked across the sky above Russia's Ural Mountains on Friday morning, causing sharp explosions and injuring more than 500 people (20 had been hospitalized in serious condition), many of them hurt by broken glass. “There was panic. People had no idea what was happening. Everyone was going around to people's houses to check if they were OK”, said Sergey Hametov, a resident of Chelyabinsk, about 1500 kilometres (930 miles) east of Moscow, the biggest city in the affected region”. (Photo by Alexey Bulaew/RIA Nowosti)