It was discovered on 16 September 1998, by American astronomer Nichole Danzl at the Kitt Peak National Observatory in Arizona.

[5] 1998 SM165 has a semi-major axis (average distance from the Sun) near the edge of the classical belt.

[3][4] The observations with the infrared Spitzer Space Telescope combined with the orbits established using the Hubble Space Telescope allow the estimation of the density, assuming the components of equal albedo.

The resulting estimate of 0.51+0.29−0.14 g/cm3[6] is similar to the density of the binary plutino 47171 Lempo (0.3–0.8 g/cm3[7]) and Saturn's moon Hyperion (0.567±0.102 g/cm3[8]) Such a low density is indicative of a highly porous composition dominated by ice.

On 22 December 2001, a minor-planet moon was discovered by American astronomer Michael Brown and Chad Trujillo using the Hubble Space Telescope.