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)

Topless activist Kaila J. walks through the rain following a “Free the Nipple” demonstration in Hampton Beach, New Hampshire August 23, 2015. (Photo by Brian Snyder/Reuters)

Devotees ride on the roof of a train as they return to the city after attending the final prayers on the first phase of Bishwa Ijtema in Dhaka January 11, 2015. Hundreds of thousands of pilgrims congregated in the Bangladeshi capital Dhaka as the first phase of this year's Bishwa Ijtema, one of the biggest Islamic gatherings in the world after the Haj in Saudi Arabia, came to an end. (Photo by Reuters/Stringer)

A man dressed as a traditional character in the “Baile de Negras” dance poses for a picture on the feast day of the Virgin of the Candelaria (Candlemas) in the town of Diriomo, some 45 km from Managua, Nicaragua on February 2, 2017 Candlemas falls forty days after Christmas and is celebrated by Catholics as the presentation of Christ at the Temple. (Photo by Inti Ocon/AFP Photo)

A Polish girl and a boy throw water over each other on Wet Monday in Szczecin, northwestern Poland, 13 April 2020. Wet Monday is a Catholic celebration held on Easter Monday mostly in Poland, but also in the Czech Republic, Slovakia, Hungary and some parts of western Ukraine. Due to the lockdown it is forbidden to celebrate this holiday in public. (Photo by Marcin Bielecki/EPA/EFE)

A photojournalist is silhouetted by the sunset as a lightning strike at a resort affected by Saturday's tsunami in Carita, Indonesia, Tuesday, December 25, 2018. Christmas celebrations traditionally filled with laughter and uplifting music were replaced by somber prayers for tsunami victims in an area hit without warning following a volcanic eruption, leaving hundreds of people dead and thousands homeless in disaster-prone Indonesia. (Photo by Fauzy Chaniago/AP Photo)

Revellers enjoying the pubs and clubs in Leeds despite concerns over Omicron on December 10, 2021. Festive revellers have hit the pubs and clubs across the UK tonight as Plan B rules come into force and fears grow over the spread of Omicron. (Photo by Nb press ltd)

The clown is on tour at Outlets on June 7, 2020 in Wuhan,Hubei Province,China.Wuhan has seen its urban life gradually get back to normal following encouragement from local city management to open up street-stalls. Since January, China has recorded more than 81,000 cases of COVID-19 and at least 3200 deaths, mostly in and around the city of Wuhan, in central Hubei province, where the outbreak first started. (Photo by Getty Images/Stringer)