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Near-Earth asteroid
2023 BU
is a
near-Earth object
that passed 9,967 ± 1 km (6,193.21 ± 0.62 mi) from the centerpoint of Earth around 27 January 2023 00:29 UT.
[3]
Since
Earth's radius
is about 6,378 km (3,963 mi), it was expected to pass approximately 3,589 ± 1 km (2,230.10 ± 0.62 mi) from the surface of Earth over the southern tip of
South America
.
[7]
It passed at an
altitude
above
low Earth orbit
which is 2,000 km (1,200 mi) and below
geostationary orbit
which is 36,000 km (22,000 mi). The asteroid is about 3?8 meters in diameter
[5]
and approached Earth from the night sky. It is the fourth closest non-impacting approach known to Earth (excluding
Earthgrazers
) after
2020 VT
4
,
2020 QG
, and
2021 UA
1
.
Orbital details
[
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]
The asteroid came to
perihelion
(closest approach to the Sun) on 27 January 2023,
[4]
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,
[2]
about five days before closest approach. It was last observed on 31 January 2023.
[1]
2023 BU closest Earth approach on 2023-Jan-27 00:29 UT
[3]
Date and time of closest approach
|
Earth distance
(
AU
)
|
Sun distance
(AU)
|
Velocity
wrt Earth
(km/s)
|
Velocity
wrt Sun
(km/s)
|
Uncertainty region
(
3-sigma
)
|
Reference
|
2023-01-27 00:29
|
0.000067
AU
(10,000
km
; 0.0261
LD
)
|
0.985 AU (147.4 million km; 383 LD)
|
9.3
|
35.2
|
± <1 km
|
Horizons
|
The gravitational effect of the 2023 Earth approach will increase the
orbital period
from 359 days to an estimated 425 days.
[8]
It will lift the perihelion and aphelion distances. The
relatively low Earth encounter speed
of 9.3 km/s (21,000 mph) is a result of a low
eccentricity
and Earth-like orbit.
Impact assessment
[
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]
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.
[9]
Impacts by objects 8 meters (26 ft) in diameter occur, on average, every 5 years; impacts by objects 4 meters (13 ft) in diameter happen, on average, once every year.
[9]
2023 BU has a 1 in 17 million chance of impacting Earth on 20 January 2110.
[10]
History of 2023 BU closest approach uncertainties for the 3500?3600 km pass of Earth's surface
JPL SBDB
solution
|
Observation arc
|
Date and time of closest approach
|
Uncertainty region
(
3-sigma
)
[a]
|
JPL 1
|
1 day (25 obs)
|
2023-01-26 21:17 ± 02:22
[11]
|
± 2,600 km
[12]
|
JPL 2
|
2 days (30 obs)
|
2023-01-27 00:17 ± 01:05
[13]
|
± 1,700 km
[14]
|
JPL 3
|
3 days (42 obs)
|
2023-01-27 00:28 ± 00:10
[15]
|
± 262 km
[16]
|
JPL 4
|
3 days (39 obs)
|
2023-01-27 00:26 ± 00:10
[17]
|
± 260 km
[18]
|
JPL 5
|
4 days (65 obs)
|
2023-01-27 00:28 ± 00:02
[19]
|
± 29 km
[20]
|
JPL 6
|
4 days (61 obs)
|
2023-01-27 00:28 ± 00:02
[21]
|
± 27 km
[22]
|
JPL 9
|
5 days (121 obs)
|
2023-01-27 00:29 ± <00:01
|
± 5 km
[23]
|
JPL 11
|
5 days (143 obs)
|
2023-01-27 00:29 ± <00:01
[24]
|
± 2 km
[25]
[b]
|
JPL 12
|
6 days (166 obs)
|
2023-01-27 00:29 ± <00:01
[5]
|
± 0.3 km
[26]
|
JPL 13
|
6 days (191 obs)
|
2023-01-27 00:29 ± <00:01
|
± 0.2 km
[27]
|
JPL 14
|
6 days (194 obs)
|
2023-01-27 00:29 ± <00:01
|
± 0.19 km
[28]
|
JPL 15
|
6 days (199 obs)
|
2023-01-27 00:29 ± <00:01
|
± 0.18 km
[29]
|
JPL 19
|
10 days (231 obs)
|
2023-01-27 00:29 ± <00:01
|
± 0.15 km
[30]
|
JPL 21
|
10 days (238 obs)
|
2023-01-27 00:29 ± <00:01
|
± 0.13 km
[31]
|
See also
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Notes
[
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]
- ^
The
JPL SBDB
time of closest approach can vary by a minute from the
Horizons
time of closest approach giving them slightly different uncertainty regions. Horizons values are calculated using the JPL SBDB time of closest approach.
- ^
JPL#11 Soln.date: 2023-Jan-26_15:02:34 PST was the active solution at the time of closest approach "2023-Jan-26 16:29 PST".
References
[
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]
External links
[
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]