Geographos orbits the Sun at a distance of 0.8–1.7 AU once every 1 years and 5 months. Its orbit has an eccentricity of 0.34 and an inclination of 13° with respect to the ecliptic. Its orbit is well-determined for the next several hundred years. Due to its high eccentricity, Geographos is also a Mars-crosser asteroid. The body's observation arc begins at Palomar, two weeks prior to its official discovery observation.
Close approaches
As a potentially hazardous asteroid, Geographos has a minimum orbital intersection distance with Earth of less than 0.05 AU and a diameter of greater than 150 meters. The Earth-MOID is currently, which translates into 11.7 lunar distances. In 1994, Geographos made its closest approach to Earth in two centuries at 5.0 Gm – which will not be bettered until 2586.
Failed ''Clementine'' mission
Geographos was to be explored by the U.S.'s Clementine mission which was launched in January 1994. However, a malfunctioning thruster ended the mission before it could approach the asteroid.
Since the 1970s, several rotational lightcurve of Geographos have been obtained from photometric observations. Lightcurve analysis gave a rotation period between 5.222 and 5.224 hours with a very high brightness variation between 1.02 and 2.03 magnitude. The Yarkovsky effect is causing a decrease in the orbital semimajor axis of, while the YORP effect is increasing the asteroid's rotation at the rate of.
Spin axis
Several lightcurve were also modeled from the abundant photometric observations. In 1994 and 1995, Polish astronomers obtained a concurring period 5.223328 hours and found a spin axis of in ecliptic coordinates . Radiometric observations gave a period of 5.223327 hours and a pole of. Two other international studies obtained a period of 5.223326 hours and a pole at and, respectively.
Shape and structure
The light curve shows a high amplitude, indicative of its elongated shape, measuring 5.0 × 2.0 × 2.1 kilometers, which corresponds to a mean-diameter of 2.5 km. The interior of the asteroid probably has a rubble-pile structure. The asteroid's high thermal inertia indicates the surface is most likely a mix of fine grains and large rocks and boulders. During the asteroid's close approach to Earth in 1994, a radar study of it was conducted by the Deep Space Network at the Goldstone Observatory, California. The resultant images show Geographos to be the most elongated object in the Solar System.
According to the observations with the Goldstone Observatory and the space-based surveys carried out by the Infrared Astronomical SatelliteIRAS and the NEOWISE mission of the Wide-field Infrared Survey Explorer, Geographos measures between 1.77 and 2.56 kilometers in diameter and its surface has an albedo between 0.26 and 0.3258. The Collaborative Asteroid Lightcurve Link adopts an albedo of 0.26 and a diameter of 2.5 kilometers based on an absolute magnitude of 15.09.
