Number 10. BELL H-13 SIOUX was a two-bladed, single engine, light helicopter built by Bell Helicopter. Westland Aircraft manufactured the Sioux under license for the British military as the Sioux AH.1 and HT. In 1947, the United States Air Force ordered the improved Bell Model 47A. Most were designated YR-13 and three winterized versions were designated YR-13A. The United States Army first ordered Bell 47s in 1948 under the designation H-13. These would later receive the name Sioux. The Bell-built H-13 B is seen airborne in this April 29, 1951 photo. The helicopter is equipped with a 173 horsepower engine, cruises at 85 miles per hour, climbs 900 feet in a minute and has a service ceiling of 11,500 feet. (Photo by AP Photo)

Gorgeous galaxies and stunning stars make up this selection of pictures from the shortlisted entries for this year’s Insight Astronomy Photographer of the Year award. The winners will be announced on 15 September, and an exhibition of the winning images will be will be displayed in a free exhibition at the Royal Observatory Greenwich’s Astronomy Centre from 17 September. Here: “Seven Magic Points”. The rusty red swirls of the circular, iron sculpture Seven Magic Points in Brattebergan, Norway mirror the rippling aurora above. (Photo by Rune Engebø/Royal Observatory Greenwich’s Astronomy Photographer of the Year 2016/National Maritime Museum)

A green iguana, or American iguana sits on an Aldabra giant tortoise, the largest tortoise of the world, in their enclosure at the zoo park of Lille, northern France, on February 11, 2019. (Photo by Philippe Huguen/AFP Photo)

A student from the General Yermolov Cadet School performs with models of swords during celebrations of Maslenitsa, or Pancake Week, a pagan holiday marking the end of winter, in southern city of Stavropol, Russia, March 6, 2019. (Photo by Eduard Korniyenko/Reuters)

Gunfire was brought to the steps of President Truman's Washington home, Blair House, as two assassins tried to kill the chief executive, November 1, 1950. One of the gunmen, Oscar Collazzo of New York, lay wounded at the bottom of Blair House's front steps after the president's police guard had finished their work, at the cost of one guards' life, Dec. 9, 1950. The second gunman was killed. (Photo by Harvey Georges/AP Photo)

Six new Canadians take their oath of citizenship while harnessed on the CN Tower's “Edgewalk” 356 metres (1,168 feet) above Toronto, Ontario, Canada in a still image from video October 9, 2018. (Photo by CN Tower/Handout via Reuters)

A traffic police officer directs traffic in Mohe City, northeast China's Heilongjiang Province, December 29, 2019. Temperatures in Mohe, “north pole” of China, often stand at below minus 40 degrees Celsius in winter mornings. Photo by Yang Siqi/Xinhua News Agency/Alamy Live News)

A person stands next to the skyline of lower Manhattan on the opening day the Edge NYC, an outdoor observation deck on the 100th floor of 30 Hudson Yards on March 11, 2020 in New York City. (Photo by Gary Hershorn/Getty Images)