18439 1994 LJ1 is a main belt asteroid with an estimated diameter of 5 km. It was discovered on June 9 1994, by Helin, E. F. at Palomar. The semi-major axis is 2.31 AU, the eccentricity is 0.206 and the inclination is 12.30 degrees.
Observations of this asteroid were made on six nights between December 2010 and February 2011. Analysis of the data showed a period of 18.291 hours.