Tactics reminiscent of the early American frontier days are now being used in Vietnam. Lieutenant Commander Donald D. Sheppard, UBN, of Coronado, California, aims a flaming arrow at a bamboo hut concealing a fortified Viet Cong bunker on the banks of the Bassac River, Vietnam on December 8, 1967. (Photo by AP Photo)

An airplane passes the moon as it makes its approach to Philadelphia International Airport, Sunday, September 7, 2014, in Philadelphia. (Photo by Matt Rourke/AP Photo)

People visit Luke Jerram's “In Memoriam”, a temporary memorial artwork for all those who lost their lives due to COVID-19, in Seaton Carew Park, Hartlepool, Britain on August 20, 2021. (Photo by Lee Smith/Reuters)

A shooting star (L, top) is seen on the night sky during the perseid meteor shower in Jankowo, near Poznan, 11 August 2016. The first half of August is traditionally the best time to look out for meteors called “shooting stars”, or perseids which are the leftover dust particles of a comet tail associated with comet Swift-Tuttle. (Photo by Lukasz Ogrodowczyk/EPA)

A tree covered with hoarfrost casts a shadow on a snowy field, shot with a drone in Sieversdorf-Hohenofen, Germany on January 31, 2021. (Photo by Patrick Pleul/dpa)

The International Space Station (ISS) moves along its orbit above at the Russian leased Baikonur cosmodrome, Kazakhstan, Thursday, July 18, 2019, with a statue of Soviet Union founder Vladimir Lenin in the foreground. Circular star tracks around the Polar Star and tracks of the ISS is the result of the camera multiple exposure with a total duration of two hours. (Photo by Dmitri Lovetsky/AP Photo)

An Iraqi Kurdish Peshmerga female officer bites a Rabbit while demonstrating skills during a graduation ceremony in the Kurdish town of Soran, about 100 kilometres northeast of the capital of Iraq's autonomous Kurdish region Arbil, on February 12, 2020. (Photo by Safin Hamed/AFP Photo)

In this Saturday, June 24, 2017 file photo, Zeid Ali, 12, left, and Hodayfa Ali, 11, comfort each other after their house was hit and collapsed during fighting between Iraqi forces and Islamic State militants in Mosul, Iraq. The Ali cousins said some of their family members are still under the rubble. (Photo by Felipe Dana/AP Photo/File)