Ukrainian servicemen patrol near the humanitarian aid center in Avdiivka, Ukraine, Saturday, February 4, 2017. Fighting in eastern Ukraine sharply escalated this week. Ukraine's military said several soldiers were killed over the past day in shelling in eastern Ukraine, where fighting has escalated over the past week. (Photo by Evgeniy Maloletka/AP Photo)

“Cub”. In the colony of penguins in South Georgia. (Photo and caption by Ondrej Zaruba/National Geographic Traveler Photo Contest)

ATTENTION! All pictures are presented in high resolution. To see Hi-Res images – just TWICE click on any picture. In other words, click small picture – opens the BIG picture. Click BIG picture – opens VERY BIG picture.

A woman takes a selfie in front of a Lunar New Year display featuring sheep at a shopping mall in Hong Kong, February 13, 2015. (Photo by Bobby Yip/Reuters)

A goat named “White On The Right” bleats as it is paraded with other goats prior to a race during the annual Easter goat racing event at the Mount Pleasant recreation ground in Tobago April 6, 2015. (Photo by Andrea De Silva/Reuters)

Dark clouds bearing down on the city on April 17, 2011 in Foshan, Guangdong Province of China. According to flood control authorities on Monday, gales as strong as 45.5 meters per second, accompanied by hailstorm, cloudburst and strong wind battered cities including Guangzhou, Foshan, Zhaoqing and Dongguan of south China's Guangdong Province on Sunday, has killed at least 17 people and injured 118. (Photo by ChinaFotoPress/Getty Images)

“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

Mazda Motor introduces the company's concept vehicle, Taiki during the press day of the 40th Tokyo Motor Show at Makuhari Messe, on October 24, 2007 in Chiba Prefecture, Japan. (Photo by Koichi Kamoshida/Getty Images)

“Contrails (short for “condensation trails”) or vapour trails are artificial clouds that are the visible trails of condensed water vapour made by the exhaust of aircraft engines. As the hot exhaust gases cool in the surrounding air they may precipitate a cloud of microscopic water droplets or, if the air is cold enough, tiny ice crystals”. – Wikipedia

Photo: An airplane leaves a vapor trail as it flies in front of he moon on January 17, 2007 above Hanover, Germany. (Photo by Alexander Hassenstein/Getty Images)