Scientists test the temperature, salinity and depth of the seawater as they prepare for the dive of the Jiaolong, China's manned submersible, on its mother ship Xiangyanghong 09, May 22, 2017. The ship arrived at the Mariana area Monday and started testing temperature, salinity and depth for Tuesday's dive in the Mariana Trench, the first of the expedition's third stage. (Xinhua/Liu Shiping)
