3688 Navajo

Navajo is an asteroid in a cometary orbit (ACO), with no observable coma but with a Tisserand's parameter just below the defined the threshold of 3.0. ACO's may be extinct comets.^[5] It is a member of the small dynamical Griqua group, a marginally unstable group of asteroids observed in the Hecuba gap, a 2:1 resonant zone with the gas giant Jupiter.^[3] The group is named after its largest member, 1362 Griqua.

Navajo is a non-family asteroid from the main belt's background population.^[4] It orbits the Sun in the outermost asteroid belt at a distance of 1.7–4.8 AU once every 5 years and 9 months (2,112 days; semi-major axis of 3.22 AU). Its orbit has a high eccentricity of 0.48 and an inclination of 3° with respect to the ecliptic.^[2] The body's observation arc begins with a precovery taken at Siding Spring Observatory, just weeks before its official discovery observation at Anderson Mesa.^[1]

Navajo has been characterized as a dark and primitive P-type asteroid.^[5] It has an absolute magnitude of 15.1.^[2] As of 2018, no rotational lightcurve of Navajo has been obtained from photometric observations. The body's rotation period, pole and shape remain unknown.^[2]

According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Navajo measures 6.086 kilometers in diameter and its surface has an albedo of 0.047.^[6]