A fisherman boats in Chao Lake where thick cyanobacteria gather on the surface on August 5, 2015 in Chaohu, Anhui Province of China. As high temperature came in summar, part of water in Anhui Province's Chao Lake breeds large tracts of cyanobacteria which not only brought pollution to sense of smell, but also affected people's life. (Photo by ChinaFotoPress/ChinaFotoPress via Getty Images)

Participants of an unauthorized opposition rally gather in Tverskaya street in central Moscow on June 12, 2017. Authorities detained Russian opposition politician Alexei Navalny and hundreds of his supporters on Monday, as they mounted demonstrations across the nation against government corruption. Over 200 were detained in Moscow and Saint Petersburg an hour into the protest, according to an NGO that tracks arrests, with Navalny himself picked up by police in his building as he was headed to the event. (Photo by Vasily Maximov/AFP Photo)

A newly married bride is seen after a mass wedding ceremony in which 2,016 couples participated, at Zocalo square in Mexico City, Mexico, March 19, 2016. Thousands of couples took part in a mass wedding ceremony Saturday in Mexico City. More than 5,000 people descended on Mexico City’s central square for the festivities. Among them were 2,165 couples ready to get married. (Photo by Edgard Garrido/Reuters)

A picture made available on 30 March 2016 shows members of the anti-terror squad of the local paramilitary force have a training in Suining, in southwest Sichuan province, China, 29 March 2016. (Photo by Zhong Min/EPA)

“The titan arum or Amorphophallus titanum (from Ancient Greek amorphos, “without form, misshapen” + phallos, “phallus”, and titan, “giant”) is a flowering plant with the largest unbranched inflorescence in the world. The titan arum's inflorescence is not as large as that of the Talipot palm, Corypha umbraculifera, but the inflorescence of the Talipot palm is branched rather than unbranched”. – Wikipedia

Photo: Kew Gardens employee Lauren Bird Royal examines the flowering of the Titan Arum lily at the Botanical Gardens at Kew on September 30, 2005 in London, England. For the first time in horticultural history, the Titan Arum lily can be seen at all three active stages in its lifecycle – in flower, fruit and leaf.The flowering corm is nearly three metres tall and weighs 91kg and is very rarely seen outside of the rainforests of Sumatra, Indonesia. (Photo by Scott Barbour/Getty Images)

A young arab boy, armed with a rifle and a knife, in the Aden Protectorate near Yemen. (Photo by Richards/Fox Photos/Getty Images). February 1938

An Olympic Airways airplane stands on the premises of the former Athens International airport, Hellenikon June 16, 2014. For about six decades Hellenikon was Athens' only airport but it closed down in 2001 to make way for a newer, more modern airport before the city hosted the 2004 Olympic Games. After languishing for years as a wasteland of crumbling terminals, Hellenikon is set for resurrection as a glitzy coastal resort. Lamda Development, controlled by Greece's powerful Latsis family and leading a consortium of Chinese and Abu-Dhabi based companies, has big dreams for the area since signing a 915 million euro deal for a 99-year lease in March 2014. (Photo by Yorgos Karahalis/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.