Lightning strikes during a storm over the Ionian Sea in Calabria, Italy on June 27, 2016. (Photo by Alfonso Di Vincenzo/Pacific Press/Rex Features)

An airplane crosses a nearly full-moon on its way to Los Angeles International Airport near Whittier, Calif., Thursday, December 24, 2015. Not since 1977 has a full moon dawned in the skies on Christmas. (Photo by Nick Ut/AP Photo)

The 26th annual National Geographic Traveler Photo Contest is now accepting submissions. Official categories include: “Travel Portraits”, “Outdoor Scenes”, “Sense of Place” and “Spontaneous Moments”. The contest is accepting entries until June 30. Photo: “Forest lights”. Aurora Borealis over the forest of the Pyhae Luosto National Park, Finland. (Photo and caption by Nicholas Roemmelt/National Geographic Traveler Photo Contest)

Gorgeous galaxies and stunning stars make up this selection of pictures from the shortlisted entries for this year’s Insight Astronomy Photographer of the Year award. The winners will be announced on 15 September, and an exhibition of the winning images will be will be displayed in a free exhibition at the Royal Observatory Greenwich’s Astronomy Centre from 17 September. Here: “Seven Magic Points”. The rusty red swirls of the circular, iron sculpture Seven Magic Points in Brattebergan, Norway mirror the rippling aurora above. (Photo by Rune Engebø/Royal Observatory Greenwich’s Astronomy Photographer of the Year 2016/National Maritime Museum)

Sharafkhaneh port and lake Urmia. Masoud Ghadiri (Iran). The summer Milky Way is very prominent in this photo. On the galaxy zone, Saturn is located besides the Lagoon nebula. On the right of the horizon, you can see the extreme light pollution of Urmia, which is caused by ever-increasing city development. (Photo by Masoud Ghadiri/National Maritime Museum)

What makes a watch the most valuable in the world? It’s supercomplicated – literally. In 1925 banker Henry Graves Jr. (considered the greatest watch collector of the 20th century) commissioned Patek Philippe to create a unique gold pocket watch. When Graves finally received it – eight years later – it was the most complex timepiece ever created by human hands... (Photo by Suzanne Plunkett/Reuters)

Lightning illuminates a thundercloud as a storm front hits the North Sea region near Westerhever, northern Germany, on August 11, 2014. (Photo by Daniel Reinhardt/AFP Photo/DPA)

Fireworks explode over Elizabeth Tower housing the Big Ben clock in London. (Photo by Kirsty Wigglesworth/Associated Press)