The newly discovered asteroid 2023 BU, observed for the 1st time by Gennadiy Borisov a couple of days ago, will have a safe and close approach to Earth on January 26th, at 23:56 UTC. I’ve just done a Horizon query for confirmation.
Asteroid’s diameter should be in a range of 4 to 9 mt. and its speed with respect to Earth is about 8 Km/s. No danger for Earth’s inhabitants but the distance is lesser than geostationary orbits of many satellites (30000-35000 Km).
Center to center least distance evaluated by Horizons is 0.00009379414178 UA, that is 14031 Km. We have to subtract the Earth radius (6378 Km) to obtain the minimum approximate distance from our planet’s surface, 7600 Km.
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JPL/HORIZONS (2023 BU) 2023-Jan-23 12:34:44
Rec #:50644526 (+COV) Soln.date: 2023-Jan-23_05:30:52 # obs: 30 (2 days)
IAU76/J2000 helio. ecliptic osc. elements (au, days, deg., period=Julian yrs):
EPOCH= 2459966.5 ! 2023-Jan-22.00 (TDB) Residual RMS= .41587
EC= .06705378261031335 QR= .9202175551592298 TP= 2460056.3394871554
OM= 306.7023024315471 W= 272.790777337173 IN= 2.458343567481403
A= .9863564887308609 MA= 269.6099806998312 ADIST= 1.052495422302492
PER= .97962 N= 1.006127953 ANGMOM= .017045897
DAN= .97873 DDN= .98514 L= 219.4956465
B= -2.4554262 MOID= .00019054 TP= 2023-Apr-21.8394871554
Asteroid physical parameters (km, seconds, rotational period in hours):
GM= n.a. RAD= n.a. ROTPER= n.a.
H= 29.215 G= .150 B-V= n.a.
ALBEDO= n.a. STYP= n.a.
ASTEROID comments:
1: soln ref.= JPL#2, OCC=6
2: source=ORB
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Ephemeris / WWW_USER Mon Jan 23 12:34:45 2023 Pasadena, USA / Horizons
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Target body name: (2023 BU) {source: JPL#2}
Center body name: Earth (399) {source: DE441}
Center-site name: (user defined site below)
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Start time : A.D. 2023-Jan-26 23:00:00.0000 UT
Stop time : A.D. 2023-Jan-27 01:00:00.0000 UT
Step-size : 1 minutes
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Target pole/equ : No model available
Target radii : (unavailable)
Center geodetic : 12.6167000,41.8667000,1.014E-12 {E-lon(deg),Lat(deg),Alt(km)}
Center cylindric: 12.6167000,4756.89324,4234.5894 {E-lon(deg),Dxy(km),Dz(km)}
Center pole/equ : ITRF93 {East-longitude positive}
Center radii : 6378.1 x 6378.1 x 6356.8 km {Equator, meridian, pole}
Target primary : Sun (R_eq= 696000.000) km
Vis. interferer : MOON (R_eq= 1737.400) km {source: DE441}
Rel. light bend : Sun {source: DE441}
Rel. lght bnd GM: 1.3271E+11 km^3/s^2
Small-body perts: Yes {source: SB441-N16}
Atmos refraction: NO (AIRLESS)
RA format : HMS
Time format : CAL
RTS-only print : NO
EOP file : eop.230120.p230414
EOP coverage : DATA-BASED 1962-JAN-20 TO 2023-JAN-20. PREDICTS-> 2023-APR-13
Units conversion: 1 au= 149597870.700 km, c= 299792.458 km/s, 1 day= 86400.0 s
Table cut-offs 1: Elevation (-90.0deg=NO ),Airmass (>38.000=NO), Daylight (NO )
Table cut-offs 2: Solar elongation ( 0.0,180.0=NO ),Local Hour Angle( 0.0=NO )
Table cut-offs 3: RA/DEC angular rate ( 0.0=NO )
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Initial IAU76/J2000 heliocentric ecliptic osculating elements (au, days, deg.):
EPOCH= 2459966.5 ! 2023-Jan-22.00 (TDB) Residual RMS= .41587
EC= .06705378261031335 QR= .9202175551592298 TP= 2460056.3394871554
OM= 306.7023024315471 W= 272.790777337173 IN= 2.458343567481403
Equivalent ICRF heliocentric cartesian coordinates (au, au/d):
X=-5.171937946033230E-01 Y= 7.742646323463939E-01 Z= 3.399295762038308E-01
VX=-1.405701873560648E-02 VY=-8.830808153728322E-03 VZ=-4.634143805486034E-03
Asteroid physical parameters (km, seconds, rotational period in hours):
GM= n.a. RAD= n.a. ROTPER= n.a.
H= 29.215 G= .150 B-V= n.a.
ALBEDO= n.a. STYP= n.a.
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Date__(UT)__HR:MN R.A._________(ICRF)_________DEC R.A.___(airless-apparent)___DEC APmag S-brt delta VmagSn VmagOb
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$$SOE
2023-Jan-26 23:56 03 19 09.044289 -43 52 36.02648 03 19 57.767343 -43 47 52.26478 12.447 n.a. 0.00009379414178 33.0598080 8.2025656
$$EOE
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Buonasera. La rete di monitoraggio dei NEO sembra efficiente, se riesce a darci il preavviso di 3 giorni su oggetti così piccoli!
Già, e credo che nei prossimi decenni le cose andranno sempre meglio. Non mi risulta sia un oggetto a composizione metallica quindi quand’anche fosse entrato in atmosfera probabilmente sarebbe esploso prima di arrivare a terra. Le probabilità che colpisca un satellite geostazionario sono infinitamente basse, praticamente nulle, ma se dovesse succedere sarebbe un bel guaio, soprattutto per la quantità di detriti generati.
saluti
A.C.
Buona serata
Secondo il sito https://www.media.inaf.it/2023/01/24/asteroide-2023-bu-flyby/
Per gli osservatori italiani sarà possibile osservare 2023 BU durante la fase di avvicinamento nella prima serata del 26 gennaio. L’ora migliore per le osservazioni sarà attorno alle 21:30 UT (22:30 ora italiana), quando l’asteroide sarà alle coordinate equatoriali Ra = 08h 11m 37,9s Dec = +24° 02′ 04,9″ (J2000), bello alto sull’orizzonte nella parte settentrionale della costellazione del Cancro, circa 9° nord-ovest dall’ammasso stellare del Presepe (M44). L’asteroide sarà di magnitudine +7,6 quindi abbastanza luminoso da essere visibile anche con un piccolo binocolo o telescopio a patto di osservare da un cielo buio.
Personalmente al momento del passaggio indosserò il casco nel caso ci sia un errore di calcolo.
Cordiali saluti
ha ha ha, nice move! 🙂
P.S.
Le souhait indescriptible de chaque astronome est que l’astéroïde frappe tous les satellites starlink les uns après les autres comme des quilles 🙂
regards
A.C.