Brain-on-a-chip. Dazzling in green and magenta this image shows the nerve fibres (in green) produced by neural stem cells (in magenta) as they grow on a synthetic gel. Captured by a technique known as confocal microscopy, the image is part of research shedding light on how tinkering with the environment can affect the way in which nerve fibres grow. (Photo by Collin Edington and Iris Lee/Massachusetts Institute of Technology/Wellcome Images)

In this 2017 photo provided by Simon Pierce, Jonathan Green checks on a fin-mounted satellite tag on a whale shark in the Galapagos Islands area of Ecuador. Despite typically being bigger than a double-decker bus, the elusive whale shark has only tiny, almost useless teeth. It's also one of the least understood animals in the ocean. (Photo by Simonjpierce.com via AP Photo)

Afghan wrestlers compete in a bout of traditional mud wrestling competition during the Friday weekend at a field in Chaman-e- Huzuri ground in Kabul on October 21, 2022. (Photo by Wakil Kohsar/AFP Photo)

Fifty Shades Darker lingerie by Coco de Mer – capturing the “inner goddess” of Anastasia Steele – is launched following record-breaking release of movie’s new trailer. Official collection developed in conjunction with E.L. James to coincide with the new Fifty Shades Darker movie. They are the first official Fifty Shades Darker products to be released ahead of the new movie whose trailer was watched 114 million times in first 24 hours, breaking Star Wars: The Force Awakens previous record. (Photo by Rankin/Coco de Mer/Rex Shutterstock)

A pair of foxes seem happy to see each other in Zandvoort, the Netherlands in the last decade of September 2024. (Photo by Anna Stelloo/Solent News)

Seven-year-old Mimi Meade winces from the sting as Dr. Richard Mulvaney inoculates her April 26, 1954 in McClean, Va., with the new Salk polio vaccine. Mrs. John Lucas, a registered nurse, holds Mimi's arm steady as she gets one of the first injections of the countrywide test. (Photo by Harvey Georges/AP Photo)

A political billboard by the artist Karen Fiorito satirising Donald Trump and Elon Musk in Phoenix, US on March 12, 2025. The artwork, titled Twitler and Putin’s Puppet Do Washington, depicts Musk as a puppet master controlling Trump. The artwork on the other side, Liar in Chief, references Project 2025, a conservative proposal to overhaul the federal government. (Photo by Eduardo Barraza/ZUMA Press Wire/Rex Features/Shutterstock)

Some of the best entries so far in the 2016 Insight Astronomy Photographer of the Year competition. There are two weeks left to enter, and the winners will be announced in September. Here: Aurora over Laksvatn Fjord, Laksvatn, Norway. The aurora borealis dances in the skies over the town of Laksvatn, with the Milky Way to the left. The image is a single shot with no compositing, only post-processing to bring out the aurora, and some colour corrections. The photographer Matt Walford said: “I love the way the northern lights look like they are just wistfully dancing over the fjord, framed by the mountains on either side”. (Photo by Matt Walford/National Maritime Museum)