Safronov Regio

Observation and naming

Safronov Regio was first observed as the New Horizons spacecraft approached Pluto and its system of moons. As Pluto rotated, a series of equatorial dark regions were observed and informally nicknamed the Brass Knuckles, with Safronov Regio being the westermost of the dark regions. It was initially informally named Krun Macula after Krun, the greatest of the five Mandaean lords of the underworld. However, the International Astronomical Union (IAU) instead officially approved the name Safronov Regio in honor of Russian astronomer Viktor Safronov, an early proponent of the planetesimal hypothesis for Solar System formation. The name was approved on 22 September 2023.