Merit Prize Winner: “A Well Earned Rest in the Sahara”. This photo of Moussa Macher, our Tuareg guide, was taken at the summit of Tin-Merzouga, the largest dune (or erg) in the Tadrat region of the Sahara desert in southern Algeria. Moussa rested while waiting for us to finish our 45-minute struggle to the top. It only took ten minutes of rolling, running, and jumping to get back down. The Tadrat is part of the Tassili N'Ajjer National Park World Heritage area, famous for its red sand and engravings and rock paintings of cattle, elephants, giraffes, and rhinos that lived there when the climate was milder. Photo location: Summit of Tin-Merzouga, Tadrat, Tassili N'Ajjer National Park, Algeria. (Photo and caption by Evan Cole/National Geographic Photo Contest)

Canadian slackliner Mia Noblet walks on a slackline (25mm wide, 3mm thick and 60m long) during “Tianmen Mountain Female High-Heeled Highline Challenge” at Zhangjiajie National Forest Park on May 27, 2018 in Zhangjiajie, Hunan Province of China. 23-year-old Canadian slackliner Mia Noblet became the first one who finished the challenge in 22 minutes and 36 seconds while 32-year-old French slackliner Mini Guesdon broke the record in 9 minutes and 24 seconds during her second attempt on Sunday. (Photo by VCG/VCG via Getty Images)

A couple ride a motorcycle along a street during snow in Altay, Xinjiang Uighur Autonomous Region, China, November 8, 2015. Picture taken November 8, 2015. (Photo by Reuters/Stringer)

Strokkur geyser against cloudy sky at sunset. Strokkur is a fountain geyser located in a geothermal area beside the Hvítá River in Iceland in the southwest part of the country, east of Reykjavík. It is one of Iceland's most famous geysers, erupting once every 6–10 minutes. Its usual height is 15–20 m, although it can sometimes erupt up to 40 m high. (Photo by Teatsche Dijkhuis/Getty Images/EyeEm)

In this Wednesday, December 2, 2015 photo, Dr. Gal Kelmer, head of the department of large animals, unties a horse after its operation at the University's Koret School of Veterinary Medicine in Rishon Lezion, Israel. “Horses have an instinctive response of flight from danger”, Kelmer said. “The minute they wake up they start trying to stand and run, even if they don't have control of their limbs. So then they fall”. (Photo by Oded Balilty/AP Photo)

A photographer is using a unique method to show the shift from day to night across famous cities in spectacular images. Daniel Marker-Moors' take on time-lapse photography – which he calls time slice – sees the photographer snap image after image, before combining them to create beautiful, vibrant works. His images usually focus on a point in the day with the most dramatic change in light, such as sunrise or sunset. Marker-Moors, from Los Angeles, begins by shooting hundreds and sometimes thousands of images from the same spot. Here: Chicago – 35 photographs, 15 minutes. (Photo by Daniel Marker-Moors/Caters News)

Crowds on the beach in Cape Canaveral, Fla., watch the launch of the SpaceX Falcon 9 Crew Dragon on its Crew-1 mission carrying four astronauts, Sunday, November 15, 2020, in this 3 1/2-minute time exposure. The rocket was launched from Launch Complex 39A at Kennedy Space Center at 7:27 p.m. Sunday evening. (Photo by Malcolm Denemark/Florida Today via AP Photo)