The announcement came of the discovery of asteroid 2021 PH27, which has the shortest orbital period among the known asteroids with about 113 Earth days. Astronomer Scott S. Sheppard of the Carnegie Institution of Science identified it in data collected by the Dark Energy Camera (DECam), an instrument designed for cosmological research that on several occasions has also proved useful for other astronomical research. In this case, the images were captured by Ian Dell’Antonio and Shenming Fu of Brown University on August 13, 2021. The orbit of 2021 PH27 is probably not stable over the long period, and studying this asteroid will help to understand the movements of objects with orbits close to that of the planet Mercury.