 According to the surveys carried out by the Japanese Akari satellite and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, "Mally" measures between 11.20 and 16.60 kilometers in diameter, and its surface has an albedo between 0.059 and 0.097.The "Collaborative Asteroid Lightcurve Link" assumes an albedo of 0.10 – a compromise value between the brighter stony (0.20) and darker carbonaceous asteroids (0.057) used for bodies with a semi-major axis between 2.6 and 2.7 AU – and calculates a diameter of 10.7 kilometers based on an absolute magnitude of 12.98.In September 2013, a rotational lightcurve of "Mally" was obtained from photometric observations taken at the Palomar Transient Factory in California.