Željava Air Base, situated on the border between Croatia and Bosnia and Herzegovina under Plješevica Mountain, near the city of Bihać, Bosnia, was the largest underground airport and military air base in the former Yugoslavia, and one of the largest in Europe. (Photo by Thomas Windisch/Exclusivepix Media)

This artist's rendering illustrates the evaporation of HD 189733b's atmosphere in response to a powerful eruption from its host star. NASA's Hubble Space Telescope detected the escaping gases and NASA's Swift satellite caught the stellar flare. (Credit: NASA's Goddard Space Flight Center)

The Oshkosh M-ATV – MRAP (Mine Resistant Ambush Protected) vehicle developed by the Oshkosh Corporation of Oshkosh, Wisconsin. It is designed to provide the same levels of protection as the larger and heavier previous MRAPs but with improved mobility and it is intended to replace M1114 HMMWVs. (wikipedia) (Photo by Alex Wong/Getty Images)

Israelis sit by as a man poses while jumping into the pool of the natural water spring of Ein al-Faraah near the Palestinian village of Doura, west of Hebron in the occupied West Bank, during the Jewish religious holiday of Sukkot (Feast of the Tabernacles) on October 17, 2019. (Photo by Hazem Bader/AFP Photo)

A man walks in the street at the start of the new curfew to counter the COVID-19 in the center of Lyon, central France, Saturday, January 16, 2021. All of France will be under a stricter curfew starting Saturday at 6 p.m. for at least 15 days to fight the spread of the coronavirus. (Photo by Laurent Cipriani/AP Photo)

Moichara or Bull race is a rural festival where a pair of bulls race each other during the monsoon season. This race is performed by a farmer in Parganas, India on July 4, 2021. (Photo by Sumit Sanyal/SOPA Images/Rex Features/Shutterstock)

Rice seedling festival is a traditional folk festival in longji, guangxi, China on June 9, 2019, during grain in ear season. (Photo by Costfoto/Barcroft Media)

“Jet Man” Richard Browning demonstrating Gravity, a human jet suit system, at the opening of the Army's Personnel Conference held at Farnborough International Conference Centre, Farnborough, Hampshire on Tuesday, November 2, 2021. (Photo by Steve Parsons/PA Images via Getty Images)