Radio heliograph antennas stand on the grassland near the Minggatu (Mingantu) Astronomical Observatory in Zhengxiangbai Banner, Xiliin (Xilin) Gol League, Inner Mongolia autonomous region on Sept 16, 2018. The Minggatu Astronomical Observatory is equipped with radio heliographs composed of 100 white parabolic antennas centered on the sun and receiving the solar radio frequencies. The resultant images are displayed through digital processing of signals from the astronomical instruments. [Photo/Xinhua]