People take part in the celebrations of Victory Day, which marks the 78th anniversary of the victory over Nazi Germany in World War Two, in Vladivostok, Russia on May 9, 2023. (Photo by Tatiana Meel/Reuters)

Children play after offering Eid al-Fitr prayers at Jama Masjid to mark the end of the holy fasting month of Ramadan, in the old quarters of Delhi, India on May 3, 2022. (Photo by Anushree Fadnavis/Reuters)

Participants of the “Lady in red“ procession, marking the day of the Summer Solstice, walk on a promenade of the Yenisei River in Krasnoyarsk, Russia on June 22, 2019. (Photo by Ilya Naymushin/Reuters)

Demonstrators react during a rally in support of legal and safe abortion and to mark the International Safe Abortion Day in Bogota, Colombia on September 28, 2021. (Photo by Luisa Gonzalez/Reuters)

A polar bear plays with a pylon during celebrations marking its first birthday in an enclosure at Tierpark Hellabrunn zoo in Munich December 9, 2014. (Photo by Michaela Rehle/Reuters)

A masked reveller poses along the flooded St. Mark's Square during a period of seasonal high water and on the first day of carnival, in Venice February 1, 2015. (Photo by Stefano Rellandini/Reuters)

Masked revellers pose in St. Mark's Square during the Venice Carnival, February 7, 2015. The Venetian carnival started on January 31 and runs until February 17, forty days before Easter celebrations. (Photo by Stefano Rellandini/Reuters)

Two years ago, Mark Rober was an engineer at NASA’s Jet Propulsion Laboratory in Pasadena, California, part of a team that worked on the Curiosity rover. For Halloween, he strapped an iPad to his chest and another to his back. Then he turned them on and used the devices’ cameras and screens to make it appear as if he had a gaping hole in the middle of his torso. (Photo By Mark Rober)