A new book published by the UK Natural History Museum showcases some of the most memorable underwater photographs taken over the last few decades in its annual wildlife photographer of the year competition. Here: Giant gathering by Tony Wu. “The first indication that something extraordinary was going on were the blows, huge numbers of them – the exhalations of huge numbers of whales. Entering the water, the photographer witnessed an extraordinary scene”. (Photo by Tony Wu/Unforgettable Underwater Photography/NHM)

Spacewalker Mark Vande Hei took his own photograph during the first spacewalk of 2018, on January 23, 2018. These sky-high pictures are better known as “space-selfies”. (Photo by Mark Vande Hei/NASA)

Skiers and snowboarders in swimwear during the Grelka Fest-2019 Festival at the Sheregesh ski resort, Kemerovo Region, Russia on April 13, 2019. (Photo by Kirill Kukhmar/TASS)

In this April 20, 2018, file aerial photo released by China's Xinhua News Agency, advection fog drifts across skyscrapers on the waterfront in Qingdao in eastern China's Shandong Province. Chinese leaders have long been sensitive about their communist country’s international image. Now, they are battling back, investing in diplomacy and a courtship of hearts and minds, just as the United States digs in on the Trump administration’s “America First” mindset. (Photo by Lu Hui/Xinhua via AP Photo/File)

A journalist (R) is attacked by residents who are trying to prevent migrants from disembarking on the Greek island of Lesbos, on March 1, 2020. The United Nation called on March 1 for calm and urged states to refrain from “excessive” force, as thousands of migrants have flooded to Turkey's border with Greece in a bid to enter the EU. A massive influx of migrants swelled along the border over the weekend after Turkey's President Recep Tayyip Erdogan threatened to open its frontier to Europe as tensions mount over its deepening conflict in Syria. (Photo by AFP Photo/Stringer)

Costumed guests arrive for the “Life Ball” charity event at the Rathaus city hall in Vienna, Austria, 10 June 2017. The 24th Life Ball is a charity fundraiser for HIV and Aids projects. (Photo by Christian Bruna/EPA/EFE)

A Togolese policeman, disguised as a terrorist, brandishes his weapon on October 20, 2022 during an anti-terrorism exercise at the Peacekeeping Operations Training Center (CEOMP). Togo's military on Thursday carried out a simulated jihadist attack in the capital Lome on Thursday, practising countering an assault and hostage-taking at a restaurant. Togo and neighbouring West African coastal states like Ghana and Benin are preparing for growing spillover from jihadist conflicts across their northern borders in Niger and Burkina Faso. (Photo by Yanick Folly/AFP Photo)

A Kenyan police officer calls for reinforcement in front of a lorry set on fire by protesters during riots in the informal settlement of Kibera in Nairobia on May 2, 2023. Kenyan riot police were out on the streets on May 2, 2023 as the opposition defied a police ban and staged new demonstrations over the cost of living crisis and last year's election results. (Photo by Luis Tato/AFP Photo)