102109 (1999 RD166) is a mid-sized asteroid with an orbit that crosses the orbit of Mars. NASA JPL has not classified 1999 RD166 as potentially hazardous because its orbit does not bring it close to Earth.
1999 RD166 orbits the sun every 1,220 days (3.34 years), coming as close as 1.62 AU and reaching as far as 2.85 AU from the sun. Based on its brightness and the way it reflects light, 1999 RD166 is probably between 1.058 to 2.366 kilometers in diameter, making it larger than 99% of asteroids, very roughly comparable in size to the U.S. Pentagon.
1999 RD166's orbit is 0.61 AU from Earth's orbit at its closest point. This means that there is a very 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.
1999 RD166's orbit is determined by observations dating back to March 24, 1998. It was last officially observed on May 25, 2022. The IAU Minor Planet Center records 596 observations used to determine its orbit.
The position of 102109 (1999 RD166) 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.
The above comparison is an artistic rendering that uses available data on the diameter of 1999 RD166 to create an approximate landscape rendering with Mount Everest in the background. This approximation is built for full-resolution desktop browsers. Shape, color, and texture of asteroid are imagined.