Looking at a lot of pictures, I always thought that the lava from Kilauea Caldera would grow bigger and bigger after dark, and I realized that it was an illusion of visual effect. We can only see the edge of the crater from time to time, and it has been steaming constantly. During the day, it is a feeling of water vapor. After dark, the temperature drops, the temperature difference between the inside and outside of the crater increases, and the water vapor becomes more. Against the background of the surrounding black, the water vapor at the bottom of the crater flashes bright red light. The photograph shows the feeling of a flame. The Jaggar Museum will have staff speaking in English in the open air before dark. As the sun sinks to the West and the temperature on the mountain drops to several degrees in a straight line, the preparation of the cold-proof clothes is indispensable.