Spacewalker Mark Vande Hei took his own photograph during the first spacewalk of 2018, on January 23, 2018. These sky-high pictures are better known as “space-selfies”. (Photo by Mark Vande Hei/NASA)

Rohingya refugee sisters Nur Kaida (R) and Ruhana hug each other at their shelter at the Palongkhali refugee camp near Cox's Bazar, Bangladesh December 21, 2017. (Photo by Marko Djurica/Reuters)

Prince Philip, the Duke of Edinburgh meets members of the cast of “Chicago” during a visit to the Adelphi Theatre in this March 4, 1999 file photo in London, England. (Photo by Anwar Hussein/Getty Images)

Cropped shot of a woman flirtatiously touching leg of man in a suit with her foot under the table. (Photo by LightField Studios/Skyfish Digital Media/Getty Images)

Private Harold L. Langhofer edges into the ball-turret, March 9, 1943. Curled in this position, he can turn the turret so that it fires in any direction. The turret can also be swung around so that the hatch opens into the plane, and the gunner can crawl into it while the Flying Fortress is in motion. (Photo by AP Photo)

A Southwest Airlines jet takes off from Reagan National Airport with a thunderhead to the east on June 20, 2017 in Alexandria, VA. (Photo by Jonathan Newton/The Washington Post)

This photo taken late on February 21, 2021 in Milo, near Catania, Sicily, and obtained on February 22, 2021 from Italian news agency Ansa, shows lava flowing along the sides of the southern crater of the Etna volcano as a new eruptive episode of tall lava fountains, known as paroxysm, occurred. (Photo by ANSA/Handout via AFP Photo)

Mount Etna erupts near Sicily, Italy on March 15, 2021. This is the thirteenth time in twenty-eight days. During the early evening of 14 March and the night between 14 and 15 March a strombolian activity at the Southeast Crater gradually increased, leading to a paroxysmal event which had its peak around 01:00 am, ash blown by the wind touched the south-southeast slope of the volcano reaching also Catania, the event ceased completely around 3:45, photo taken from Milo near Catania on March 15, 2021. (Photo by Salvatore Allegra/Anadolu Agency via Getty Images)