The Northern Lights glow green in a spectacular light show above a field of trees frozen solid with snow. (Photo by Jaak Sarv/Solent News & Photo Agency)

Children dressed up as Hindu Lord Krishna pose during Janmashtami festival celebrations marking the birth anniversary of Krishna in Agartala, India August 24, 2016. (Photo by Jayanta Dey/Reuters)

A Somali police officer arrests a suspected rebel member of the al Qaeda-affiliated al Shabaab among beach goers in Mogadishu. Al Shabaab claimed responsibility for today's pre-dawn attack on a Kenyan university campus near the Somali border. The following gallery examines who is al Shabaab. Here: Somali police officer (R) arrests a suspected rebel member (L) of the Al Qaeda-affiliated al Shabaab among beach goers at the Lido beach north of Somalia's capital Mogadishu March 23, 2012. (Photo by Feisal Omar/Reuters)

An instructor (C) adjusts the posture of students of flight attendant major during a training session at Anhui Foreign Languages University, in Hefei, Anhui province, China, May 25, 2015. (Photo by Reuters/China Daily)

A participant in costume uses a mobile phone at a Halloween event in Kawasaki, south of Tokyo, Japan October 29, 2017. (Photo by Kim Kyung-Hoon/Reuters)

Indian Air Force officers stretch before taking part in full dress rehearsal for India's Republic Day parade in Kolkata, January 23, 2018. (Photo by Rupak De Chowdhuri/Reuters)

A general view of Copacabana beach during the coronavirus disease (COVID-19) outbreak in Rio de Janeiro, Brazil, March 22, 2020. (Photo by Ricardo Moraes/Reuters)

An internally displaced Afghan girl plays outside her shelter, amid the spread of the coronavirus disease (COVID-19), in Kabul, Afghanistan on May 7, 2020. (Photo by Mohammad Ismail/Reuters)