Mr. Zhong Hua, of Johns Hopkins University School of Medicine, took this image of the peripheral nerves (those outside of the brain) in an 11.5-day-old mouse embryo, magnified five times. (Photo by Zhong Hua)

“Diver in Magic Kingdom”. Green Lake (Grüner See) is located Tragöss Austria. In spring snowmelt raises the lake level about 10 meters. This phenomenon, which lasts only a few weeks covering the hiking trails, meadows, trees. The result is magical to watch diving landscapes. Photo location: Grüner See at Tragöss, Austria. (Photo and caption by Marc Henauer/National Geographic Photo Contest)

The double compound eyes of a male St. Mark's fly (Bibio marci), submitted by Dr. David Maitland from Feltwell, UK. (Dr. David Maitland)

A chevrotain or mouse deer feeds in its enclosure at Zurich Zoo, Zurich, Switzerland, October 17, 2012. (Photo by Patrick B. Kraemer/AP)

A Lion-Tailed macaque holds a big block of ice with a mix of frozen vegetables and fruit at the zoo in Leipzig, central Germany, Friday, July 19, 2013. Weather forecasts predict sunny weather and warm temperatures for Germany in the next few days. (Photo by Jens Meyer/AP Photo)

Vegetarian 19-year-old model Courtney Stodden gets ready to serve veggie hot dogs wearing a lettuce bikini during a People for the Ethical Treatment of Animals (PETA) free veggie dog handout on Capitol Hill in Washington, DC, July 16, 2014. (Photo by Jim Watson/AFP Photo)

North Korea has closed its borders in fear of the spread of the Ebola virus. But at a time when the secretive state was still welcoming tourists, former aid worker Andrew Macleod made the journey to the repressive nation. Andrew's holiday snaps and camera footage provide a unique insight into the reclusive country, where he came across deserted motorways, metro stations plastered with propaganda and attractive border guards. Here: a female traffic police officer in the snow in February 2013, in Pyongyang, North Korea. (Photo by Andrew Macleod/Barcroft Media)

Locals harvest their potatoes as Mount Sinabung spews volcanic ash in Karo, North Sumatra province, Indonesia on August 10, 2020. (Photo by Sastrawan Ginting/Antara Foto via Reuters)