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)

A white Bengal tiger cub plays with its mother in a zoo in the Siberian city of Novosibirsk, about 2,800 kilometers (1,750 miles) east of Moscow, Russia, Tuesday, April 21, 2015. Two blue-eyed Bengal tiger cubs were born in March to a couple of white tigers at Novosibirsk zoo. (Photo by Ilnar Salakhiev/AP Photo)

A candle burns during a vigil in Aotea Square to remember victims of the Paris attacks on November 14, 2015 in Auckland, New Zealand. According to reports, over 150 people were killed in a series of bombings and shootings across Paris, including at a soccer game at the Stade de France and a concert at the Bataclan theater. (Photo by Hannah Peters/Getty Images)

A young girl chases pigeons as Muslim worshippers gather to perform the Eid al-Fitr morning prayer at the Grand Mosque in Saudi Arabia's holy city of Mecca to mark the end of the fasting month of Ramadan, on May 13, 2021. (Photo by Abdulghani Essa/AFP Photo)

Medical workers wearing gear enter a residential area placed under the enhanced movement control order (EMCO) due to a drastic increase in the number of COVID-19 cases recorded in Sunway, outskirt of Kuala Lumpur, Malaysia, Friday, July 2, 2021. Malaysia starts to further tighten movement curbs and impose a curfew in most areas in its richest state Selangor and parts of Kuala Lumpur, where coronavirus cases remain high despite a national lockdown last month. (Photo by Vincent Thian/AP Photo)

Tourists wearing protective face masks walk in Nanluoguxiang alley, a famous touristic spot at Hutong neighborhood, in Beijing, China, 01 May 2020. China is loosening up nationwide restrictions after months of lockdown over the coronavirus crisis. Labor Day in the country kicked off with a long weekend and an extended holiday, from 01 to 05 May, after the tourism industry has been hit during the coronavirus and COVID-19 disease pandemic. (Photo by Roman Pilipey/EPA/EFE)

Visitors enjoy food at a table bounded by a banner with a character fast food restaurant Kentucky Fried Chicken, in Jakarta, Indonesia, on June 23, 2020. The display banner is useful for limiting physical distance for visitors who eat on the spot. The Indonesian government has imposed a new set of regulations known as “new normal”, which will be implemented in stages starting in early June for some provinces. (Photo by Jefta Images/Barcroft Media via Getty Images)