The NASA Extreme Environment Mission Operations (NEEMO) 21 mission began on July 21 as an international crew of aquanauts splashed down to the undersea Aquarius Reef Base, located 62 feet below the surface of the Atlantic Ocean in the Florida Keys National Marine Sanctuary. The NEEMO 21 crew will perform research both inside and outside the habitat during a 16-day simulated space mission. During simulated spacewalks carried out underwater, they will evaluate tools and mission operation techniques that could be used in future space missions, including journeys to Mars. (Photo by Karl Shreeves/NASA)
Alpine Skiing, FIS Alpine Skiing World Cup, Men's Parallel Giant Slalom, Alta Badia, Italy on December 19, 2016. Hostesses take a bath in a Jacuzzi pool during the race. (Photo by Stefano Rellandini/Reuters)
A citizen rides in smog on December 20, 2016 in Jinan, Shandong Province of China. Air quality index (AQI) readings exceeded 400 and some schools have suspended classes in Jinan. (Photo by VCG/VCG via Getty Images)
Fire over Vieira de Leiria, Portugal, on October 16, 2017 as a series of deadly wildfires broke out across Spain and Portugal as the approach of Hurricane Ophelia whipped up strong winds that fanned the flames. (Photo by Helio Madeiras/News Pictures)
A man, wearing a protective mask following an outbreak of the coronavirus disease (COVID-19), walks in Tokyo, Japan on March 17, 2020. (Photo by Edgard Garrido/Reuters)
People wear face masks while participating in the annual Memorial Day Parade on May 25, 2020 in the Staten Island borough of New York City. Dozens of cars and nearly 100 members of the patriotic motorcycle group Rolling Thunder joined the event. This year’s parade was diminished in size and in person-to-person contact due to the coronavirus outbreak. Across the country, events honoring the nation’s veterans have been cancelled or scaled back as America continues to experience high numbers of deaths and new cases of COVID-19. (Photo by Spencer Platt/Getty Images)
People stand in front of a black ribbon, symbolising remembrance and mourning, being projected onto the Sydney Opera House on February 9, 2023 in solidarity with Turkey and Syria after a massive earthquake devastated the two countries. (Photo by David Gray/AFP Photo)