German troops in Stalingrad, USSR. September 10, 1942. (Photo by TASS)

Ammunition airlift into besieged Khe Sanh, Operation Pegasus, April 1968. (Photo by Larry Burrows/AP Photo)

German Nazi leader Adolf Hitler (1889 - 1945) enjoys a quiet picnic between meetings, circa 1933. Picture 196 of a series of collectable images published in Germany during the Nazi period, entitled “Deutschland Erwacht” (Germany Awakes). (Photo by Heinrich Hoffmann/Hulton Archive/Getty Images)

A woman hangs strips of salted meat she collected from different places during the Muslim's Eid al-Adha or Festival of Sacrifice, in Lahore, Pakistan, Sunday, August 2, 2020. Pakistanis are celebrating the Eid al-Adha, or the Feast of the Sacrifice, to mark the willingness of the Prophet Ibrahim – Abraham to Christians and Jews – to sacrifice his son. During the holiday Muslims slaughter sheep and cattle, distribute part of the meat to the poor. (Photo by K.M. Chaudary/AP Photo)

Spectators watch from Canaveral National Seashore as a SpaceX Falcon 9 rocket carrying 60 Starlink satellites launches from pad 39A at the Kennedy Space Center on October 6, 2020 in Cape Canaveral, Florida. This is the 13th batch of satellites placed into orbit by SpaceX as part of a constellation designed to provide broadband internet service around the globe. (Photo by Paul Hennessy/NurPhoto via Getty Images)

A squirrel crawls along an electrical cable as a kingfisher takes off from it in New Delhi, India, October 24, 2020. (Photo by Chine Nouvelle/SIPA Press/Rex Features/Shutterstock)

Tigray refugees who fled the conflict in the Ethiopia's Tigray arrive with their donkey on the banks of the Tekeze River on the Sudan-Ethiopia border, in Hamdayet, eastern Sudan, Saturday, November 21, 2020. (Photo by Nariman El-Mofty/AP Photo)

A robot used to assist Covid-19 patients is seen in an elevator on December 5, 2020 in New Delhi, India. The “Mitra” robot can connect patients with their loved ones, and can assist healthcare workers on the frontlines of the pandemic by minimisng the risk of infections caused by close contact. The Yatharth Hospital, which is treating Covid-19 patients in Noida, on the outskirts of New Delhi, is one of a handful of hospitals in India that has started to use robots. (Photo by Anindito Mukherjee/Getty Images)