2023 BU
{{Short description|Near-Earth asteroid}}
{{Use dmy dates|date=January 2023}}
__NOTOC__
{{Infobox planet
| minorplanet = yes
| name = 2023 BU
| background = #FFC2E0
| image = 2023 BU Goldstone radar 2023-01-29.jpg
| image_scale =
| caption = Radar image of 2023 BU by the Goldstone Solar System Radar on 29 January 2023
| discoverer = Gennadiy Borisov
| discovery_site = {{abbr|MARGO|private observatory of Gennadiy Borisov, discoverer of the object}}, Nauchnyi, Crimea
| discovered = 21 January 2023
| mpc_name = 2023 BU
| alt_names = gb00553
| mp_category = {{nowrap|NEO{{·}}Apollo}}
| epoch = 25 February 2023 (JD 2460000.5)
(Post-flyby orbit)
| uncertainty = 1
| observation_arc = 10 days (231 obs)
| earliest_precovery_date =
| aphelion = 1.230 AU
| perihelion = 0.9840 AU
| time_periastron = 27 January 2023 04:30
| semimajor = 1.107 AU
| eccentricity = 0.1111
| period = 1.16 yr
| mean_anomaly = 28.7°
| mean_motion =
| inclination = 3.75°
| asc_node = 125.5°
| arg_peri = 355.8°
| moid = {{Convert|0.00046|AU|km LD|abbr=on}}
| mean_diameter = 3–8 meters (CNEOS)
| rotation = ~77 secondsNortholt Branch Observatory: [https://twitter.com/NBObservatories/status/1618975466773438467 77 seconds with an amplitude of 0.9 mag]
| albedo =
| spectral_type =
| magnitude =
| abs_magnitude = {{val|29.4|0.5}} (JPL)
29.4 (MPC)
}}
2023 BU is a near-Earth object that passed {{cvt|9967 ± 1|km|mi}} from the centerpoint of Earth around 27 January 2023 00:29 UT. Since Earth's radius is about {{cvt|6378|km|mi}}, it was expected to pass approximately {{cvt|3589 ± 1|km|mi}} from the surface of Earth over the southern tip of South America. It passed at an altitude above low Earth orbit which is {{cvt|2000|km|mi|abbr=unit}} and below geostationary orbit which is {{cvt|36000|km|mi|abbr=unit}}. The asteroid is about 3–8 meters in diameter and approached Earth from the night sky. It is the fourth closest non-impacting approach known to Earth (excluding Earthgrazers) after {{mpl|2020 VT|4}}, {{mpl|2020 QG}}, and {{mpl|2021 UA|1}}.
Orbital details
File:Animation of 2023 BU around Sun.gif
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.
{{anchor|CA}}
| class="wikitable" style="text-align: center; font-size: 0.9em;"
|+2023 BU closest Earth approach on 2023-Jan-27 00:29 UT ! Date and time of closest approach ! Earth distance ! Sun distance ! Velocity ! Velocity ! Uncertainty region ! Reference | ||||||
| 2023-01-27 00:29 | {{Convert|0.000067|AU|km LD|abbr=unit|lk=on|sigfig=3}} | {{Convert|0.985|AU|e6km LD|abbr=unit}} | 9.3 | 35.2 | ± <1 km | [https://ssd.jpl.nasa.gov/horizons_batch.cgi?batch=1&COMMAND=%272023+BU%27&START_TIME=%272023-01-27%2000:29%27&STOP_TIME=%272023-01-28%27&STEP_SIZE=%271%20day%27&QUANTITIES=%2719,20,22,39%27 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 {{convert|9.3|km/s|mph|abbr=on}} is a result of a low eccentricity and Earth-like orbit.
| class=wikitable style="font-size: 0.9em;"
|+Orbital elements | |||||
| valign=top
! Parameter ! Epoch ! Period ! Aphelion ! Perihelion ! Semi-major axis ! Eccentricity ! Inclination | |||||
| valign=top
! Units ! ! (days) !colspan=3|AU ! !(°) | |||||
| align=center
! Pre-flyby | 358.9 | 1.05 | 0.926 | 0.988 | 0.063 | 2.35° |
| align=center
! Post-flyby | 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 {{convert|8|m|sp=us}} in diameter occur, on average, every 5 years; impacts by objects {{convert|4|m|sp=us}} in diameter happen, on average, once every year. 2023 BU has a 1 in 17 million chance of impacting Earth on 20 January 2110.
{{anchor|History}}
{{Closest non-impacting asteroids to Earth}}
See also
Notes
{{notelist|refs=
{{efn|name=enlarged|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.}}
{{efn|name=active|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
{{Reflist|refs=
|title=JPL Small-Body Database Browser: (2023 BU)
|publisher=Jet Propulsion Laboratory
|url=https://ssd.jpl.nasa.gov/tools/sbdb_lookup.html#/?sstr=2023BU&view=OPC
|archive-url=https://archive.today/20230122171527/https://ssd.jpl.nasa.gov/tools/sbdb_lookup.html%23/?sstr=2023BU&view=OPC
|archive-date=2023-01-22
|url-status=live
|accessdate=2023-01-28}}
|title=2023 BU
|work=Minor Planet Center
|url=https://www.minorplanetcenter.net/db_search/show_object?object_id=2023+BU
|accessdate=2023-01-28}}
|title = MPEC 2023-B72 : 2023 BU
|url = https://minorplanetcenter.net/mpec/K23/K23B72.html
|work = Minor Planet Electronic Circular
|publisher = Minor Planet Center
|date = 2023-01-22
|accessdate = 2023-01-22}}
|title=Perihelion @ 0.984AU on 27 Jan 2023
|publisher=JPL Horizons
|type=Perihelion occurs when rdot flips from negative to positive
|url=https://ssd.jpl.nasa.gov/horizons_batch.cgi?batch=1&COMMAND=%272023+BU%27&START_TIME=%272023-Jan-27%2004:00%27&STOP_TIME=%272023-Jan-27%2005:00%27&STEP_SIZE=%271%20min%27&QUANTITIES=%2719%27
|accessdate=2023-01-26}}
|title=Horizons Batch showing epoch 2022-Oct-25 and 2023-Feb-25
|publisher=JPL Horizons
|url=https://ssd.jpl.nasa.gov/horizons_batch.cgi?batch=1&COMMAND=%272023+BU%27&TABLE_TYPE=%27ELEMENTS%27&START_TIME=%272022-10-25%27&STOP_TIME=%272023-02-25%27&STEP_SIZE=%274%20months%27&CENTER=%27@Sun%27&OUT_UNITS=%27AU-D%27
|accessdate=2023-01-24}}
|title=Earth Impact Effects Program
|publisher=Imperial College London / Purdue University
|author1=Robert Marcus |author2=H. Jay Melosh |author3=Gareth Collins
|url=https://impact.ese.ic.ac.uk/ImpactEarth/cgi-bin/crater.cgi?dist=0.0001&distanceUnits=1&diam=8&diameterUnits=1&pdens=&pdens_select=3000&vel=11.4&velocityUnits=1&theta=45&wdepth=&wdepthUnits=1&tdens=2750
|access-date=2023-01-24}} (using 8-meter diameter, density of 3000 kg/m3, speed of 11.4 km/s, and impact angle of 45°)
|title=Earth Impact Risk Summary: 2023 BU
|publisher=NASA/JPL Near-Earth Object Program Office
|url=https://cneos.jpl.nasa.gov/sentry/details.html#?des=2023%20BU
|accessdate=2023-02-11}}
|title=NASA System Predicts Small Asteroid to Pass Close by Earth This Week
|publisher=Jet Propulsion Laboratory
|date=2023-01-25
|url=https://www.jpl.nasa.gov/news/nasa-system-predicts-small-asteroid-to-pass-close-by-earth-this-week
|accessdate=2023-01-26}}
}}
External links
- {{NeoDys|2023+BU}}
- {{ESA-SSA|2023BU}}
- {{JPL small body|id=54339759}}
- Archived [https://archive.today/20230122062528/https://cneos.jpl.nasa.gov/scout/%23/object/gb00553 Scout entry]
{{2023 in space}}
{{Small Solar System bodies}}
{{Portal bar|Astronomy|Outer Space}}
{{Authority control}}
{{DEFAULTSORT:2023 BU}}