|Discovery date 22 January 2013|
Minor planet category Apollo NEO, PHA
Discovered 22 January 2013
Absolute magnitude 20.4
Discoverer Mount Lemmon Survey
|MPC designation 2013 BP73|
Observation arc 4645 days (12.72 yr)
Earth moid 0.2 cm
Asteroid group Apollo asteroid
|Discovered by Mt. Lemmon Survey (G96)|
Aphelion 2.1633 AU (323.63 Gm) (Q)
2013 BP73 (also written 2013 BP73) is an Apollo near-Earth asteroid and potentially hazardous object. From discovery until August 2013 when Sentry updated to planetary ephemeris (DE431), it had the 4th highest impact threat on the Palermo Technical Impact Hazard Scale. It was discovered on 22 January 2013 by the Mount Lemmon Survey at an apparent magnitude of 21 using a 1.5-meter (59 in) reflecting telescope. It has an estimated diameter of 310 meters (1,020 ft). Six Precovery images from April 2003 have been located. It was removed from the Sentry Risk Table on 3 January 2014.
It has an observation arc of 10 years with an uncertainty parameter of 2. Perturbations by Earth, Venus, and Mercury will increase the orbital uncertainty over time. When the asteroid only had an observation arc of 52 days, virtual clones of the asteroid that fit the uncertainty region in the known trajectory showed a 1 in 588,000 chance that the asteroid could impact Earth on 11 December 2096. With a 2096 Palermo Technical Scale of −3.42, the odds of impact by 2013 BP73 in 2096 were about 2630 times less than the background hazard level of Earth impacts which is defined as the average risk posed by objects of the same size or larger over the years until the date of the potential impact. Using the nominal orbit, JPL Horizons shows that the asteroid will be 0.9 AU (130,000,000 km; 84,000,000 mi) from Earth on 11 December 2096. 2013 BP73 will make a close approach to Earth on 17 December 2018 that should allow a refinement to the known trajectory.