These powerful images capture the spear-wielding tribes of Papua new Guinea who believe they are possessed with the spirit of the crocodile. They show how the Kangunaman clansmen scar their backs to resemble reptile scales while the Huli Wigmen wear elaborate headdresses to signal they are ready for battle. (Photo by Trevor Cole/Media Drum World)

A guard secures gates of a catfish farm visited by a group of foreign reporters in Pyongyang, North Korea April 17, 2017. (Photo by Damir Sagolj/Reuters)

Mourning woman. (Photo by Rich Legg/Getty Images/iStockphoto)

A protester from the People for the Ethical Treatment of Animals (PETA) displays a placard from a bathtub as a people looks on during a demonstration to call on the public to eat more vegetables to save water, in Sao Paulo on August 2, 2016. (Photo by Cris Faga via ZUMA Wire)

The North Side Skull & Bone Gang stand together during the wake up call for Mardi Gras, Tuesday, February 9, 2016, in New Orleans. Their costumes are intended to represent the dead and they bring a serious message, reminding people of their mortality and the need to live a productive and good life. (Photo by Brynn Anderson/AP Photo)

Indian Hindu devotees carry an idol of the elephant-headed Hindu deity Ganesha for immersion in a temporary pond near Sangam in Allahabad on September 4, 2017. The Ganesh Chaturthi festival is a popular 11-day religious festival which is annually celebrated across India. (Photo by Sanjay Kanojia/AFP Photo)

Revellers take part in the “Canto a la Tierra” parade on January 3, 2018, during the Carnival of Blacks and Whites in Pasto, Colombia, the largest festivity in the south- western region of the country. More than 10,000 people among artists, craftsmen and revellers take part in the Blacks and Whites Carnival, which has its origins in the mix of the multiple Andean, Amazonian and Pacific cultural expressions. It is celebrated every year from January 2 to 6 in the city of Pasto and is part of UNESCO's Intangible Cultural Heritage of Humanity since 2009. (Photo by Luis Robayo/AFP Photo)

M42 Subtle V1 cropped. One of the most well-known astronomical objects in our universe is the Orion Nebula and this image depicts the wider region of the Orion Molecular Cloud Complex that is its home. This complex also includes another popular target for astrophotographers, the Horsehead Nebula, as well as Barnard’s Loop and the Running Man Nebula, which can be seen to the left of this photograph. (Photo by Patrick Gilliland)