A couple looks at their flooded street from behind their home's window in La Plata, in Argentina's Buenos Aires province, where at least 35 people were killed by flooding overnight, on April 3, 2013. (Photo by Natacha Pisarenko/Associated Press)

“NASA's Pathfinder, Pathfinder Plus, Centurion and Helios Prototype were an evolutionary series of solar- and fuel-cell-system-powered unmanned aerial vehicles. AeroVironment, Inc. developed the vehicles under NASA's Environmental Research Aircraft and Sensor Technology (ERAST) program. They were built to develop the technologies that would allow long-term, high-altitude aircraft to serve as “atmospheric satellites”, to perform atmospheric research tasks as well as serve as communications platforms”. – Wikipedia

Photo: The solar-electric Helios Prototype flying wing is flies over the Hawaiian islands of Niihau and Lehua during the first solar-powered test flight July 14, 2001 from the U.S. Navy's Pacific Missile Range Facility on Kauai, HI. The 18-hour flight was a functional checkout of the aircraft's systems and performance in preparation for an attempt to reach sustained flight at 100,000 feet altitude later in the summer. (Photo Courtesy of NASA/Getty Images)

People visit the Antelope Valley California Poppy Reserve in Lancaster, California, to view the flowers blooming on April 6, 2023. California’s biologically diverse landscapes are home to more than 7,000 species of native plants, and the California Poppy, also known as golden poppy, a flowering plant native to the United States and Mexico became the official state flower in 1903. (Photo by Frederic J. Brown/AFP Photo)

A billboard depicting a soldier, with a slogan reading “Contract service. A real man's job”, in St. Petersburg, Russia, 02 June 2023. On 24 February 2022, Russian troops entered Ukrainian territory in what the Russian president declared a “Special Military Operation”, starting an armed conflict. (Photo by Anatoly Maltsev/EPA)

In this picture taken on September 5, 2023, students practice contortionism at the Flower Studio in Ulaanbaatar. Mongolian circus performers fly through the air of a cavernous hall inspectors have warned could collapse at any time, one of the few places left to train if they hope to travel the world with their country's spectacular big top shows. (Photo by Pedro Pardo/AFP Photo)

Spanish lamb march during a military parade on the national holiday known as “Hispanidad” or Hispanic Day in Madrid, Spain on October 12, 2022. (Photo by Burak Akbulut/Anadolu Agency via Getty Images)

A person watches the sunrise from the Edge observation deck at Hudson Yards on the first day of spring on March 20, 2021 in New York City. (Photo by Noam Galai/Getty Images)

Tube passengers take a selfie next to a London underground roundel designed for the launching of the Night Tubes on display at Oxford Circus underground station in London, Britain, 19 August 2016. The long delayed Night Tubes service launched on 19 August. The 24-hour service will operate on Fridays and Saturdays. (Photo by Hannah Mckay/EPA)