Kale grows at Kajodlingen farm in Gothenburg, Sweden, September 28, 2016. They are doing it on the rooftops, on tower block balconies and even on a disused railway: Swedes have discovered a passion for urban gardening as a way of growing fresh food and getting back in touch with nature. Part of a global movement, an increasing number of Swedish city-dwellers are growing their own in window boxes and allotments or are visiting public gardens built in or on industrial or office spaces. (Photo by Maxim Shemetov/Reuters)

A rooster bred for its all black appearance walks through the yard of a small backyard farm on February 3, 2017 on the outskirts of Jakarta, Indonesia. The roosters, called Ayam Cemani, are completely black including their bones and meat and are often sold for use in rituals. (Photo by Ed Wray/Getty 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)

“NASA's Pathfinder, Pathfinder Plus, Centurion and Helios Prototype were an evolutionary series of solar- and fuel-cell-system-powered unmanned aerial vehicles. AeroVironment, Inc. developed the vehicles under NASA's Environmental Research Aircraft and Sensor Technology (ERAST) program. They were built to develop the technologies that would allow long-term, high-altitude aircraft to serve as “atmospheric satellites”, to perform atmospheric research tasks as well as serve as communications platforms”. – Wikipedia

Photo: The solar-electric Helios Prototype flying wing is flies over the Hawaiian islands of Niihau and Lehua during the first solar-powered test flight July 14, 2001 from the U.S. Navy's Pacific Missile Range Facility on Kauai, HI. The 18-hour flight was a functional checkout of the aircraft's systems and performance in preparation for an attempt to reach sustained flight at 100,000 feet altitude later in the summer. (Photo Courtesy of NASA/Getty Images)

In this Thursday, May 8, 2014 photo, Iranian coal miners push metal carts to be loaded with coal at a mine near the city of Zirab 212 kilometers (132 miles) northeast of the capital Tehran, on a mountain in Mazandaran province, Iran. International sanctions linked to the decade-long dispute over Iran's nuclear program have hindered the import of heavy machinery and modern technology in all sectors, and coal mining is no exception. (Photo by Ebrahim Noroozi/AP Photo)

Plaster cast moulds of victims of the Mount Vesuvius eruption lie on a display table in a laboratory at Pompeii October 13, 2015. An expert team made up of archaeologists, radiologists, orthodontists and anthropologists began on September 2015 to use CAT scan technology (computerised axial tomography) to peer inside the plaster cast moulds of Pompeii's victims, in a study that has added more detail to previous findings. A 16-layer scan had to be used in order to penetrate the hardened plaster but the results showed up impressive skeletal remains and near perfect teeth. (Photo by Alessandro Bianchi/Reuters)

In this Wednesday, July 23, 2014 file photo, Omaha photographer Lane Hickenbottom photographs the night sky in a pasture near Callaway, Neb. With no moon in the sky, the Milky Way was visible to the naked eye. More than one-third of the world’s population can no longer see the Milky Way because of man-made lights, according to a scientific paper by Light Pollution Science and Technology Institute's Fabio Falchi and his team members, published on Friday, June 10, 2016. (Photo by Travis Heying/The Wichita Eagle via AP Photo)

Women are reflected on silver panels of the French luxury brand Louis Vuitton flagship store at the Central Business District in Beijing, Wednesday, March 6, 2019. China will bar government authorities from demanding overseas companies hand over technology secrets in exchange for market share, a top economic official said Wednesday, addressing a key complaint at the heart of the current China-U.S. trade dispute. (Photo by Andy Wong/AP Photo)