A TV journalist reports next to a life-size cutout of Pope Francis outside the Catholic Nunciature before the pontiff arrives in Mexico City, Friday, February 12, 2016. Pope Francis is arriving in Mexico on Friday for a week-long visit. (Photo by Christian Palma/AP Photo)

Vietnam’s Son Doong cave, the largest in the world, could hold a 40-story skyscraper inside. The pristine ecosystem has its own river and jungle. Despite its size, Son Doong wasn’t discovered until 1991. It was lost again for nearly two decades and was fully explored for the first time in 2009. (Photo by Jason Speth/HuffPost)

Dennis Hong a professor of Mechanical & Aerospace Engineering at UCLA Samueli School of Engineering attempts to impede the movement of ARTEMIS, a full-sized humanoid robot with first-of-its-kind technology in Los Angeles, California, U.S., April 13, 2023. (Photo by Mike Blake/Reuters)

Military items for women are seen in a store in Erbil, Iraq January 24, 2017. (Photo by Marius Bosch/Reuters)

A girl reacts during a rehearsal for the Independence Day military parade in central Kiev, Ukraine, August 19, 2016. (Photo by Valentyn Ogirenko/Reuters)

A general view of the ghost town of a former Soviet military radar station near Skrunda, Latvia, April 9, 2016. (Photo by Ints Kalnins/Reuters)

“Yunarmiya” (Young Army) All-Russia National Military Patriotic Social Movement Association members compete during the 7th military-patriotic game “Yunarmiya, forward!” dedicated to Victory Day at the Museum-reserve “Gorki Leninskie” in Gorki Leninskie, Russia, 29 April 2025. A total of 160 teams of Yunarmiya and military-patriotic detachments attended the games, each team consisting of seven people aged between 12 and 17 years old. The games are a continuation of the Soviet military-sports competitions for children and teenagers, “Zarnitsa” (since 1967) and “Orlyonok (Eaglet)” (since 1972). (Photo by Sergei Ilnitsky/EPA/EFE)

A view motorists have grown accustomed seeing, a military truck made by Oshkosh Corp. is taken for a test drive Thursday, April 11, 2013 in Oshkosh, Wis. Faced with deep cuts in U.S. military spending, and the end of the wars in Iraq and Afghanistan, Oshkosh Corp. is laying off 900 employees in its defense division based in Oshkosh. Approximately 700 hourly workers at the state's largest manufacturer will lose their jobs in mid-June, followed by approximately 200 salaried employees through July. (Photo by Mark Hoffman via The Journal Sentinel)