A police officer chases shoppers to clear the streets of the Red Light market on the first day of lockdown to stop the spread of the coronavirus disease (COVID-19) in Monrovia, Liberia on April 11, 2020. (Photo by Derick Snyder/Reuters)

Nikolai Vasilyev, 64, dressed as Father Frost, the Russian equivalent of Santa Claus, water-skis along the Yenisei River outside the Siberian city of Krasnoyarsk, Russia December 19, 2017. Vasilyev, former teacher of the Siberian State Aerospace University, constructed the water skis out of plastic foam and designed the sticks to propel him forward, while travelling on the water surface. (Photo by Ilya Naymushin/Reuters)

A young girl takes selfie with Easter rabbit sculpture during the Easter eggs (Pysanka) and rabbit exhibition in front of St. Sophia Cathedral in Kiev, Ukraine, 05 April 2018. Ukrainians will mark Orthodox Easter on 08 April 2018, according to Julian calendar. (Photo by Sergey Dolzhenko/EPA/EFE/Rex Features/Shutterstock)

Five-year-old sniffing dog “Vine” wears protection goggles against the sun and dust as he poses together with Giulia Gausemann for photographers, at the sniffing dogs school of the German Army (Bundeswehr) in Daun, Germany, July 24, 2020. The Bundeswehr sniffing dogs school and the veterinarian university of Hanover are developing a training programme to sniff out the coronavirus disease (COVID-19) with dogs at airports, border crossings and other highly frequented places. (Photo by Wolfgang Rattay/Reuters)

A view of Yarimoglu sinkhole (obruk), caused by some form of collapse of the surface layer in 2009, in Konya province, Turkiye on May 15, 2025. The gigantic pit formed between the fields where intensive irrigation activities are carried out is expanding and growing every year. (Photo by Abdullah Dogan/Anadolu via Getty Images)

Londoners sleep on the platform and on the train tracks at Aldwych Underground station,London, during heavy all night Nazi bombing raids, October 8, 1940. (Photo by AP Photo)

France's Alize Cornet celebrates scoring a point in the first round match of the French Open tennis tournament against Italy's Roberta Vinci at the Roland Garros stadium, in Paris, France, Monday, May 25, 2015. (Photo by Christophe Ena/AP Photo)

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.