[2] The stony asteroid has a short rotation period of 2.6 hours and measures approximately 7.9 kilometers in diameter.
In June 2020, a companion was discovered by Brian Warner, Robert Stephens and Alan Harris.
[4][5] Suomi is a member of the Hungaria family, which form the innermost dense concentration of asteroids in the Solar System.
[21] The Collaborative Asteroid Lightcurve Link (CALL) agrees with IRAS, and adopts an albedo of 0.157 and a diameter of 7.9 kilometers with an absolute magnitude of 13.146.
[5] Since 1991, a large number of rotational lightcurves of Suomi have been obtained from photometric observations (also see infobox).