Eurocopter's X³ high-speed hybrid helicopter demonstrator performs, September 6, 2010. The Eurocopter X³ (X-Cubed) is an experimental high-speed compound helicopter developed by Eurocopter (now Airbus Helicopters). A technology demonstration platform for Eurocopter “high-speed, long-range hybrid helicopter” or H³ concept, the X³ achieved 255 knots in level flight on 7 June 2013, setting an unofficial speed record for a helicopter. (Photo by Reuters/HO/Eurocopter/Penna)

Competitors in the Big Air challenge at the Proryv-2016 festival of extreme sports in Moscow, Russia on March 27, 2016. (Photo by Xinhua/Rex Features/Shutterstock)

Dead leaf or almost by Guilhem Duvot. Taken in Nován Stráž, Slovakia. Describe what is pictured? A dead leaf grasshopper. How does this image fit with the theme of the competition? The perfect camouflage – nature is amazing. I saw the grasshopper only because it jumped. (Photo by Guilhem Duvot/Royal Society of Biology)

A person wearing a face mask is reflected in an art work entitled “A=V” by Ben Cullen Williams, amid the coronavirus disease (COVID-19) outbreak, in Covent Garden, London, Britain on October 16, 2020. (Photo by John Sibley/Reuters)

A mural depicting NHS nurse Melanie Senior, based on a photograph by Johannah Churchill, which The National Portrait Gallery commissioned artist Peter Barber to create in Manchester's Northern Quarter, on October 19, 2020 in Manchester, England. Greater Manchester's leaders including Mayor Andy Burnham will want better financial arrangements for workers affected before they agree for the region to be moved into a Tier 3 Covid-19 lockdown. (Photo by Christopher Furlong/Getty Images)

In this Thursday, October 3, 2019 photo, a female black bear sleeps with its tongue out high up in a Ponderosa pine tree near Clark Fork School in the Rattlesnake neighborhood of Missoula, Mont. The bear's cub, not pictured, was snoozing on a nearby branch. (Photo by Tommy Martino/The Missoulian via AP Photo)

“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

A tale of two foxes. Surprising behaviour, witnessed in Wapusk national park, on Hudson Bay, Canada, in early winter. Red foxes don’t actively hunt Arctic foxes, but where the ranges of two predators overlap, there can be conflict. Though the light was poor, the snow-covered tundra provided the backdrop for the moment that the red fox paused with the smaller fox in its mouth in a grim pose. (Photo by Don Gutoski/2015 Wildlife Photographer of the Year)