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2023 BU is a near-Earth object that passed from the centerpoint of Earth around 27 January 2023 00:29 UT. Since Earth's radius is about , it was expected to pass approximately from the surface of Earth over the southern tip of South America. It passed at an altitude above low Earth orbit which is and below geostationary orbit which is . The asteroid is about 3–8 meters in diameter and approached Earth from the night sky. It is the fifth closest non-impacting approach known to Earth (excluding Earthgrazers) after , , , and .
Orbital details
The asteroid came to perihelion (closest approach to the Sun) on 27 January 2023, four hours after closest approach with Earth. 2023 BU was first imaged by Gennadiy Borisov at Nauchnyi, Crimea, on 21 January 2023 23:53 UT, about five days before closest approach. It was last observed on 31 January 2023.
+2023 BU closest Earth approach on 2023-Jan-27 00:27 UT Date and time of closest approach Earth distance(AU) Sun distance(AU) Velocitywrt Earth(km/s) Velocitywrt Sun(km/s) Uncertainty region(3-sigma) Reference 2023-01-27 00:27 9.3 35.1 ± 0.05 km Horizons
The gravitational effect of the 2023 Earth approach will increase the orbital period from 359 days to an estimated 425 days. It will lift the perihelion and aphelion distances. The relatively low Earth encounter speed of is a result of a low eccentricity and Earth-like orbit.
+Orbital elements Parameter Epoch Period(p) Aphelion(Q) Perihelion(q) Semi-major axis(a) Eccentricity(e) Inclination(i) Units (days)AU(°) Pre-flyby 2022-Oct-25 358.9 1.05 0.926 0.988 0.063 2.35° Post-flyby 2023-Feb-25 425.4 1.23 0.984 1.11 0.111 3.75°
Impact assessment There was no risk of an Earth impact during the 2023 Earth approach. Assuming the asteroid is at the larger size estimate of 8 meters in diameter, if it had entered the atmosphere it would not have reached the ground intact and would breakup around 30 km above the ground, thus representing only minimal threat to life.
Impacts by objects in diameter occur, on average, every 5 years; impacts by objects in diameter happen, on average, once every year. 2023 BU has a 1 in 17 million chance of impacting Earth on 20 January 2110.
+History of 2023 BU closest approach uncertainties for the 3500–3600 km pass of Earth's surface JPL SBDBsolution Observation arc Date and time of closest approach Uncertainty region(3-sigma) JPL 1 1 day (25 obs) 2023-01-26 21:17 ± 02:22 ± 2,600 kmArchive JPL 1 Horizons JPL 2 2 days (30 obs) 2023-01-27 00:17 ± 01:05 ± 1,700 kmArchive JPL 2 Horizons JPL 3 3 days (42 obs) 2023-01-27 00:28 ± 00:10 ± 262 kmArchive JPL 3 Horizons JPL 4 3 days (39 obs) 2023-01-27 00:26 ± 00:10 ± 260 kmArchive JPL 4 Horizons JPL 5 4 days (65 obs) 2023-01-27 00:28 ± 00:02 ± 29 kmArchive JPL 5 Horizons JPL 6 4 days (61 obs) 2023-01-27 00:28 ± 00:02 ± 27 kmArchive JPL 6 Horizons JPL 9 5 days (121 obs) 2023-01-27 00:29 ± <00:01 ± 5 kmArchive JPL 9 Horizons JPL 11 5 days (143 obs) 2023-01-27 00:29 ± <00:01 ± 2 kmArchive JPL 11 Horizons JPL 12 6 days (166 obs) 2023-01-27 00:29 ± <00:01 ± 0.3 kmArchive JPL 12 Horizons JPL 13 6 days (191 obs) 2023-01-27 00:29 ± <00:01 ± 0.2 kmArchive JPL 13 Horizons JPL 14 6 days (194 obs) 2023-01-27 00:29 ± <00:01 ± 0.19 kmArchive JPL 14 Horizons JPL 15 6 days (199 obs) 2023-01-27 00:29 ± <00:01 ± 0.18 kmArchive JPL 15 Horizons JPL 19 10 days (231 obs) 2023-01-27 00:29 ± <00:01 ± 0.15 kmArchive JPL 19 Horizons JPL 21 10 days (238 obs) 2023-01-27 00:29 ± <00:01 ± 0.13 kmArchive JPL 21 Horizons
See also List of asteroid close approaches to Earth in 2023
Notes
References
External links
Archived