A wide-angle view shows the ascent of the shuttle Challenger on January 28, 1986. In the seconds after ignition, the rocket engines' hot blast began the process of destruction. (Photo by NASA)

Serbian police officers of the Special Anti-Terrorist Unit pose for a picture in their base outside Belgrade October 8, 2014. When the killing of an unarmed black teenager by a white policeman in Ferguson, Missouri, in August sparked sometimes violent protests, the response of police in camouflage gear and armoured vehicles wielding stun grenades and assault rifles seemed more like a combat operation than a public order measure. Some U.S. police departments have recently acquired U.S. military-surplus hardware from wars abroad, but there are many law enforcers around the world whose rules of engagement also allow the use of lethal force with relatively few restrictions. But for every regulation that gives police wide scope to use firearms, there is another code that sharply limits their use. In Serbia, police may use measures ranging from batons to special vehicles, water cannon and tear gas on groups of people who have gathered illegally and are behaving in a way that is violent or could cause violence, but they may use firearms only when life is endangered. (Photo by Marko Djurica/Reuters)

Adventurer Sam Cossman movies towards the huge lava lake wearing a custom built industrial proximity heat suit on December 20, 2014 in Ambrym, Vanuatu. (Photo by Conor Toumarkine/Barcroft Media)

Two guests pose prior to the Dolce & Gabbana 2021 women's spring-summer ready-to-wear collection during the Milan's fashion week in Milan, Italy, Wednesday, September 23, 2020. (Photo by Luca Bruno/AP Photo)

People pose near a new Banksy artwork in Rothesay Avenue, Nottingham, Britain on October 17, 2020. (Photo by Carl Recine/Reuters)

Kashmiri women walk in a garden covered with fallen Chinar leaves on the outskirts of Srinagar, Indian controlled Kashmir, Wednesday, November 4, 2020. Kashmiris collect fallen leaves in autumn to make charcoal for use during winters. (Photo by Dar Yasin/AP Photo)

A pro-democracy protester wears a hat in the shape of a yellow rubber duck, which has become a recent symbol for the ongoing protests, during an anti-government rally in Bangkok on November 22, 2020. (Photo by Lillian Suwanrumpha/AFP Photo)

A medical worker in protective gear sprays mist on her colleague during a hot day at an outdoor clinic for coronavirus tests at a public health facility in the southwestern city of Gwangju, South Korea, 05 June 2020. (Photo by Yonhap/EPA/EFE)