Wedges of an orange generate enough current and electrical juice – 3.5 volts – to power an LED. The fruit’s citric acid helps electrons flow from galvanized nails to copper wire in this 14-hour exposure. This image was published in September’s Visions of Earth, a trio of photos that appear in each issue of National Geographic. (Photo by Caleb Charland/National Geographic)

The Royal Observatory just announced its Astronomy Photographer Of The Year 2013 winners. Australian photographer Mark Gee was chosen among a thousand amateur and professional photographers around the globe to win the top title. His work is part of an exhibition of the winning photographers, which opened on Sept. 19 at the Royal Observatory Greenwich. The Royal Observatory shared with us the winners and notable mentions of the competition. Their descriptions of the prizewinners can be found below the images.

A vendor (C) cuts slaughtered dogs for sale at his roadside stall in Duong Noi village, outside Hanoi December 16, 2011. While animal rights activists have condemned eating dog meat as cruel treatment of the animals, it is still an accepted popular delicacy for some Vietnamese, as well in some other Asian countries. Duong Noi is well-known as a dog-meat village, where hundreds of dogs are killed each day for sale as popular traditional food. Dog-eating as a custom is rooted in Vietnam and was developed as a result of poverty. One kilogram of dog meat costs about 130,000 dongs ($6.2). (Photo by Reuters/Kham)

“The white tiger is a recessive mutant of the Bengal tiger, which was reported in the wild from time to time in Assam, Bengal, Bihar and especially from the former State of Rewa”. – Wikipedia. (Photo by Tambako The Jaguar)

A replica of the truck made from matchsticks by Janusz Urbanski is pictured at his flat in Ruda Slaska, Poland May 4, 2016. Janusz Urbanski has a one of a kind chessboard he never plays, a personalised guitar he does not strum and a boat he cannot sail. Why? They are all made from tens of thousands of matches. For the last 40 years, the former Polish miner and ironworker has harboured a passion to build replicas of objects, buildings and famous sites with just matchsticks and glue. (Photo by Kacper Pempel/Reuters)

A dune buggy driver trains before competing in a sand dune drag racing event on January 8, 2016, as part of the Liwa 2016 Moreeb Dune Festival in the Liwa desert, some 250 kilometres southwest of Abu Dhabi. The festival, which attracts participants from around the Gulf region, includes a variety of races (cars, bikes, falcons, camels and horses) or other activities aimed at promoting the country's folklore. (Photo by Karim Sahib/AFP Photo)

A tourist pets a cat before the “Horus protects Ramses II as a child”, dating to the reign of the Ancient Egyptian New Kingdom pharaoh (1303-1213 BC), at the Egyptian Museum in the centre of Egypt's capital Cairo on October 19, 2022. (Photo by Amir Makar/AFP Photo)

A reveler celebrates New Year's Eve in Kuala Lumpur, Malaysia on December 31, 2022. (Photo by Hasnoor Hussain/Reuters)