A pedestrian carries an umbrella as they stroll past an advertisment as a rainstorm moves through Sacramento, Calif., Wednesday, February 13, 2019. Rain is falling widely in Northern California and is expected to spread south. (Photo by Rich Pedroncelli/AP Photo)

“A meteor streaked across the sky above Russia's Ural Mountains on Friday morning, causing sharp explosions and injuring more than 500 people (20 had been hospitalized in serious condition), many of them hurt by broken glass. “There was panic. People had no idea what was happening. Everyone was going around to people's houses to check if they were OK”, said Sergey Hametov, a resident of Chelyabinsk, about 1500 kilometres (930 miles) east of Moscow, the biggest city in the affected region”. (Photo by Alexey Bulaew/RIA Nowosti)

“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)

Russian police cadets march during general rehearsal of the Victory Day parade on the Dvortsovaya Square in St. Petersburg, Russia, 07 May 2021. The military parade marking the 76th anniversary of the victory over Nazi Germany in the World War II will take place on the Dvortsovaya Square on 09 May 2021. (Photo by Anatoly Maltsev/EPA/EFE)

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)

A health worker applies a dose of the AstraZeneca vaccine during the first day of a three-day COVID-19 vaccination campaign for people over age 35 in the Complexo da Maré favela of Rio de Janeiro, Brazil, Brazil, Thursday, July 29, 2021. Some recipients will be monitored to study the rate of protection the vaccines provide and the extent to which virus variants are circulating. (Photo by Bruna Prado/AP Photo)

A couple pours water on their dogs during a hot day, in Rome, Thursday, August 12, 2021. In Italy, 15 cities received warnings from the health ministry about high temperatures and humidity with peaks predicted for Friday. The cities included Rome, Florence and Palermo, but also Bolzano, which is usually a refreshing hot-weather escape in the Alps. (Photo by Andrew Medichini/AP Photo)

A local resident performs traditional horse racing during a celebration marking the 70th anniversary of the founding of Yushu Tibetan Autonomous Prefecture, in northwest China's Qinghai Province, August 4, 2021. (Photo by Xinhua News Agency/Rex Features/Shutterstock)