Photo taken on July 31, 2013 shows an unusual astronomical phenomena above the sky in Boao Town of Qionghai City, south China's Hainan Province. (Xinhua/Guo Cheng)

Photo taken on July 31, 2013 shows an unusual astronomical phenomena above the sky in Boao Town of Qionghai City, south China's Hainan Province. (Xinhua/Guo Cheng)

Photo taken on July 31, 2013 shows an unusual astronomical phenomena above the sky in Boao Town of Qionghai City, south China's Hainan Province. (Xinhua/Guo Cheng)

Photo taken on July 31, 2013 shows an unusual astronomical phenomena above the sky in Boao Town of Qionghai City, south China's Hainan Province. (Xinhua/Guo Cheng)

Photo taken on July 31, 2013 shows an unusual astronomical phenomena above the sky in Boao Town of Qionghai City, south China's Hainan Province. (Xinhua/Guo Cheng)