11857 (1988 RK9) is a mid-sized asteroid orbiting between Mars and Jupiter in the main portion of the asteroid belt. NASA JPL has not classified 1988 RK9 as potentially hazardous because its orbit does not bring it close to Earth.
1988 RK9 orbits the sun every 1,870 days (5.12 years), coming as close as 2.56 AU and reaching as far as 3.38 AU from the sun. Based on its brightness and the way it reflects light, 1988 RK9 is probably between 6.801 to 15.207 kilometers in diameter, making it larger than 99% of asteroids, very roughly comparable in size to the San Francisco Bay.
1988 RK9's orbit is 1.55 AU from Earth's orbit at its closest point. This means that there is an extremely wide berth between this asteroid and Earth at all times.
Orbital simulations conducted by NASA JPL's CNEOS do not show any close approaches to Earth.
1988 RK9's orbit is determined by observations dating back to Aug. 16, 1988. It was last officially observed on June 23, 2023. The IAU Minor Planet Center records 2,965 observations used to determine its orbit.
The position of 11857 (1988 RK9) is indicated by a ◯ pink circle. Note that the object may not be in your current field of view. Use the controls below to adjust position, location, and time.