Mount Sinabung is seen during an eruption from Surbakti village in Karo, North Sumatra, Indonesia, April 20, 2015. The local government is preparing the relocation of residents from three of the villages that were destroyed. (Photo by Tibta Pangin/Getty Images/Anadolu Agency)

People walk past debris on May 3, 2015 in Bhaktapur, Nepal. A major 7.8 earthquake hit Kathmandu mid-day on Saturday, and was followed by multiple aftershocks that triggered avalanches on Mt. Everest that buried mountain climbers in their base camps. (Photo by David Ramos/Getty Images)

A man holds a child after rescuing him from a kindergarten affected by a fire at a commercial building, in Ningde, Fujian province, China, September 16, 2015. According to local media, more than 260 people were evacuated due to the fire, which broke out Wednesday morning. No causalities have been reported and the cause of it is still unknown. (Photo by Reuters/China Daily)

Kyrgyz men on horseback compete during their traditional game of “Oodarysh” during the celebrations of the 90th anniversary formation of the Chui region in the village of Kuntu some 20 kms from Bishkek on May 27, 2016. (Photo by Vyacheslav Oseledko/AFP Photo)

A demonstrator argues with policewomen after she turned up her shirt and was taken out from a protest to demand the resignation of Brazilian President Dilma Rousseff, on March 13, 2016 in Paulista Avenue in Sao Paulo. Protesters, many draped in the Brazilian national flag, poured into the streets of Brasilia and Rio de Janeiro on Sunday at the start of mass demonstrations seeking to bring down President Dilma Rousseff. Authorities in Sao Paulo, Brazil's biggest city and an opposition stronghold, said they were bracing for a million protesters. (Photo by Miguel Schincariol/AFP Photo)

A young woman flashes the victory sign in front of a bonfire as Turkish Kurds gather during Newroz celebrations for the new year in Diyarbakir, southeastern Turkey, on March 21, 2018. Newroz (also known as Nawroz or Nowruz) is an ancient Persian festival, which is also celebrated by Kurdish people, marking the first day of spring, which falls on March 21. (Photo by Ilyas Akengin/AFP Photo)

Macro or Micro? Scientists’ pictures baffle our sense of scale. It began when Stephen Young, a geography professor at Salem State University in Massachusetts, tricked his biologist colleague Paul Kelly into thinking a satellite image was one of his electron microscope scans. Can you guess whether they are close-up or very far away? (Photo by Paul Kelly)

“The McDonnell Douglas KC-10 Extender is an air-to-air tanker aircraft in service with the United States Air Force derived from the civilian DC-10-30 airliner. The KC-10 was the second consecutive McDonnell Douglas transport aircraft to be selected by the US Air Force following the C-9 Nightingale. The similar KDC-10 is in service with the Royal Netherlands Air Force.”

Photo: A B-52G Stratofortress aircraft takes off with another B-52G close behind. Three cells of six B-52 and KC-10 Extender aircraft will takeoff seconds apart under combat conditions during the minimum interval takeoff exercise. The exercise is a part of an operational readiness inspection by the Strategic Air Command Inspector General Team. (Photo by USAF). 1998