Cao Zhen, chief scientist of China's Large High Altitude Air Shower Observatory (LHAASO), poses for a photo with the sand table of LHAASO at the Institute of High Energy Physics (IHEP) under the Chinese Academy of Sciences (CAS), Feb. 23, 2021. Based on the observations of China's LHAASO, one of the country's key national science and technology infrastructure facilities, Chinese scientists have measured the brightness of the standard candle in high-energy astronomy. They achieved an accurate measurement in the ultra-high energy band from 0.3 to 1.1 PeV (1 PeV is equivalent to one quadrillion electronvolts) for the first time, thus calibrating the brightness of the standard candle over an unprecedented energy range. (Xinhua/Jin Liwang)
