To mark World Water Day, on March 22nd Solidarités International and its agency BDDP Unlimited will roll out a campaign to build awareness of the scourge of undrinkable water.

Second World War veteran 90 year old William Walker launches the Scottish Poppy Appeal, together with soldiers from the Royal Highland Fusiliers, 2nd Battalion the Royal Regiment of Scotland, on October 27, 2011 in Penicuick, Scotland. Mr Walker, who was wounded while serving in Burma in 1943 with the Royal Scots, helped the soldiers form the shape of ninety to celebrate the 90th anniversary of the annual November campaign. (Photo by Jeff J Mitchell/Getty Images)

Bikers passes along the High Street on March 18, 2012 in Royal Wootton Bassett, England. The ride, in its third and final year and involving thousands of bikers started at Hullavington airfield and aims to honour the people of Royal Wootton Bassett and to raise money for the Afghan Heroes charity. (Photo by Matt Cardy/Getty Images)

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.