1999 RK257 is a large asteroid whose orbit extends beyond the orbit of Neptune. NASA JPL has not classified 1999 RK257 as potentially hazardous because its orbit does not bring it close to Earth.
1999 RK257 orbits the sun every 102,000 days (279.26 years), coming as close as 40.59 AU and reaching as far as 44.95 AU from the sun. Based on its brightness and the way it reflects light, 1999 RK257 is probably between 55.533 to 124.177 kilometers in diameter, making it larger than 99% of asteroids, very roughly comparable in size to the U.S. state of Delaware.
1999 RK257's orbit is 39.60 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.
1999 RK257's orbit is determined by observations dating back to Sept. 11, 1999. It was last officially observed on Sept. 13, 1999. The IAU Minor Planet Center records 8 observations used to determine its orbit.
The position of 1999 RK257 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.