'Blue moon' appears for a second time in 2018

Photo taken on Saturday, March 31, 2018 shows the blue moon hanging over a stadium in Kaili city, in southwest China's Guizhou Province.A 'blue moon' appeared for the second time this year on Saturday, March 31, 2018. A blue moon is means a second full moon within one a calendar month, which is quite rare. The next blue moon is due in October 2020. [Photo: IC]