This image is NGC 6543 known as the Cat's Eye Nebula as it appears to the Chandra X-Ray Observatory and Hubble Telescope. A planetary nebula is a phase of stellar evolution that the sun should experience several billion years from now, when it expands to become a red giant and then sheds most of its outer layers, leaving behind a hot core that contracts to form a dense white dwarf star. This image was released October 10, 2012. (Photo by J. Kastner/NASA/CXC/RIT)

The Arcaid awards highlight the best architectural photographs of the year – pictures of everything from giant arenas to tiny huts. The shortlisted photographs will be exhibited at the World Architecture Festival in Berlin, from 16 to 18 November, with an overall winner announced during the event’s gala dinner. Here: The stage for Haduwa Arts & Culture Institute, Ghana. Architect: (applied) Foreign Affairs. Nominated in the Sense of Place category. The open-air auditorium of this arts institute in Apam, Ghana, is built from ultra-strong curved bamboo. (Photo by Julien Lanoo)

Revellers enjoy themselves during Hogmanay celebrations in Edinburgh, Scotland on December 31, 2017. (Photo by Russell Cheyne/Reuters)

Climate change activist Greta Thunberg reacts during a news conference during COP25 climate summit in Madrid, Spain, December 9, 2019. (Photo by Juan Medina/Reuters)

A long exposure image shows star trails from the abandoned submerged orthodox church of St. Nicholas without roof, submerged in the Mavrovo Lake, near Mavrovi Anovi, North Macedonia, 17 March 2019. Constructed in 1850 and submerged in 1952 due to the construction of the hydro system Mavrovo, the church St. Nicholas continues to attract the attention of almost every visitor as it peaks from the water. (Photo by Georgi Licovski/EPA/EFE)

A Palestinian boy holds an umbrella as he runs near houses that witnesses said were destroyed or damaged by Israeli shelling during the most recent conflict between Israel and Hamas, on a rainy day in the east of Gaza City November 16, 2014. (Photo by Suhaib Salem/Reuters)

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 woman looks out of a dusty window after boarding a bus to be transported to see the casket of Nelson Mandela at the Union Buildings in Pretoria, South Africa, Wednesday December 11, 2013. On Thursday, December 5, 2013, Mandela died at the age of 95. (Photo by Markus Schreiber/AP Photo)