Six new Canadians take their oath of citizenship while harnessed on the CN Tower's “Edgewalk” 356 metres (1,168 feet) above Toronto, Ontario, Canada in a still image from video October 9, 2018. (Photo by CN Tower/Handout via Reuters)

The competition is run by Royal Observatory Greenwich sponsored by Insight Investment and in association with BBC Sky at Night Magazine. This year astrophotographers from 91 countries sent in more than 4,200 spectacular entries. Here: The Milky Way rises above an isolated lighthouse in Tasmania. Shot by James Stone of Australia. (Photo by James Stone/Astronomy Photographer of the Year 2018)

US marines watch the mushroom cloud from an atomic explosion rise above the Yucca flats, Nevada during a US nuclear weapons test. (Photo by Keystone/Getty Images). USA, 1945

This breathtaking view from the world's tallest building shows a thick blanket of smoggy fog smother Dubai. The mist almost completely covers the huge sculptures which dominate the skyline. And the spectacular view from the Burj Khalifa – standing at a staggering 828 metres tall – shows the city engulfed by the thick fog. And the smoggy fog reaches heights of up to 400 metres as it rises above the impressive skyscrapers in Dubai. (Photo by Bjoern Lauen/Solent News/SIPA Press)

Graffiti saying “justice” partially seen above flood waters in Asuncion, December 27, 2015. More than 100,000 people have had to evacuate from their homes in the bordering areas of Paraguay, Uruguay, Brazil and Argentina due to severe flooding in the wake of heavy summer rains brought on by El Nino, authorities said on Saturday. (Photo by Jorge Adorno/Reuters)

People walk along the Dune du Pilat (Dune of Pilat), the tallest sand dune in Europe, in La Teste de Buch, near Bordeaux, France, June 15, 2016. The dune has a volume of about 60,000,000 m³, measuring around 500 m wide from east to west and 2.7 km in length from north to south. Its height is currently 110 meters above sea level. (Photo by Sergio Perez/Reuters)

Gorbea Natural Park is a protected area located between the provinces of Alava and Vizcaya in the Basque Country of northern Spain. Gorbea takes its name from its highest peak, the Gorbea (or Gorbeia) at 1,482 metres (4,862 ft) above sea level.

A view of the world's highest 280-meter bungee jumping platform opened at the Milad Tower, a landmark in the Iranian capital Tehran, on September 11, 2024. The world's highest bungee jumping platform attracts great interest among the younger generation in Iran, especially women. Those who jump from the platform experience an unforgettable adventure with the thrill of soaring down from a height of 280 meters while watching the view of Tehran from above. (Photo by Fatemeh Bahrami/Anadolu via Getty Images)