Brain-on-a-chip. Dazzling in green and magenta this image shows the nerve fibres (in green) produced by neural stem cells (in magenta) as they grow on a synthetic gel. Captured by a technique known as confocal microscopy, the image is part of research shedding light on how tinkering with the environment can affect the way in which nerve fibres grow. (Photo by Collin Edington and Iris Lee/Massachusetts Institute of Technology/Wellcome Images)

Most people know Nikon as a purveyor of pro and consumer-grade digital cameras. But the company's expertise with optics bleeds over into related markets – it's one of the science community's major suppliers of microscopes. And each year the company asks the community to send it some of their favorite images of tiny objects. A panel of scientists and journalists have chosen the best of this past year's submissions, which Nikon has placed on its Small World site.

Photo: Honorable Mention. “Snow crystal, illuminated with colored lights (5x)”. (Photo by Dr. Kenneth Libbrecht, California Institute of Technology (Caltech), Department of Physics, Pasadena, California, USA)

A brig with scarlet sails travels on the Finnish Gulf coast during a rehearsal for the the Scarlet Sails festivities marking school graduation in St. Petersburg, Russia, early Saturday, June 27, 2020. This year the festival will not be held in the city center, but on the Finnish Gulf. Due to the coronavirus pandemic, there will be no spectators but the event will be broadcast on television. (Photo by Dmitri Lovetsky/AP Photo)