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Asteroid 2010 RF12

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Well, I've been investigating how one goes about finding the azimuth and elevation of an asteroid pass. It isn't easy, but the JPL Horizons system has the answers. It isn't an easy program to understand, and you access it by telnet (how 1992), but it's also pretty cool. I ran the system for the asteroid that will pass within 1/5 of the distance to the moon to us. I've posted the system output below. This data is for 122º W Longitude and 45º North Latitude. The columns you probably want to use are the Azimuth and Elevation. I've cut the portions of model output that have less than 0 elevation. (Click "Read More" for the data)

Update: Guh. I hate Matlab. Anyway, I added an image of the trajectory as seen from Oregon. North is to the right, west is on the top. I know, it sucks… I don't know enough about Matlab to fix it. Also, 90º overhead is 0, and 0º is 90.

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Ephemeris / PORT_LOGIN Wed Sep  8 09:40:43 2010  Pasadena, USA   / Horizons    
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Target body name: (2010 RF12)                     {source: JPL#6}
Center body name: Earth (399)                     {source: DE405}
Center-site name: (user defined site below)
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Start time      : A.D. 2010-Sep-07 00:00:00.0000 UT-07:00
Stop  time      : A.D. 2010-Sep-09 00:00:00.0000 UT-07:00
Step-size       : 10 minutes
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Target pole/equ : No model available
Target radii    : (unavailable)                                                
Center geodetic : 238.000000,45.0000478,-0.000347 {E-lon(deg),Lat(deg),Alt(km)}
Center cylindric: 238.000000,4517.59088,4487.3484 {E-lon(deg),Dxy(km),Dz(km)}
Center pole/equ : High-precision EOP model        {East-longitude +}
Center radii    : 6378.1 x 6378.1 x 6356.8 km     {Equator, meridian, pole}    
Target primary  : Sun                             {source: DE405}
Interfering body: MOON (Req= 1737.400) km         {source: DE405}
Deflecting body : Sun, EARTH                      {source: DE405}
Deflecting GMs  : 1.3271E+11, 3.9860E+05 km^3/s^2                              
Small perturbers: Ceres, Pallas, Vesta            {source: SB405-CPV-2}
Small body GMs  : 6.32E+01, 1.43E+01, 1.78E+01 km^3/s^2                        
Atmos refraction: YES (Earth refraction model)
RA format       : DEG
Time format     : CAL 
Time zone       : UT-07:00
RTS-only print  : NO       
EOP file        : eop.100907.p101129                                           
EOP coverage    : DATA-BASED 1962-JAN-20 TO 2010-SEP-07. PREDICTS-> 2010-NOV-28
Units conversion: 1 AU= 149597870.691 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 )                           
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Initial FK5/J2000.0 heliocentric ecliptic osculating elements (AU, DAYS, DEG):
 EPOCH=  2455446.5 ! 2010-Sep-07.00 (CT)         Residual RMS= .51054         
 EC= .1790426100393394  QR= .8185988097139194  TP= 2455532.390114616        
 OM= 165.5596199702477  W= 284.0221727285949   IN= 3.599336147379268        
Asteroid physical parameters (KM, SEC, rotational period in hours):
 GM= n.a.               RAD= n.a.              ROTPER= n.a.                 
 H= 28.298              G= .150                B-V= n.a.                    
 ALBEDO= n.a.           STYP= n.a.                   
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Date_(ZONE)_HR:MN     Azi_(r-appr)_Elev  r-ObsEcLon  r-ObsEcLat
****************************************************************
$SOE
2010-Sep-07 18:50 *r   88.0837   1.2209 345.2093905   8.7187668
2010-Sep-07 19:00 *    89.9485   2.7959 345.1984220   8.5009369
2010-Sep-07 19:10 *    91.8184   4.4307 345.1623414   8.3374745
2010-Sep-07 19:20 *    93.6971   6.0909 345.1133871   8.1983984
2010-Sep-07 19:30 *    95.5881   7.7611 345.0566579   8.0711552
2010-Sep-07 19:40 C    97.4951   9.4329 344.9944504   7.9500074
2010-Sep-07 19:50 C    99.4218  11.1011 344.9278998   7.8320371
2010-Sep-07 20:00 C   101.3720  12.7617 344.8576092   7.7156172
2010-Sep-07 20:10 N   103.3495  14.4114 344.7839147   7.5997670
2010-Sep-07 20:20 N   105.3582  16.0471 344.7070087   7.4838547
2010-Sep-07 20:30 N   107.4022  17.6657 344.6270009   7.3674481
2010-Sep-07 20:40 A   109.4855  19.2644 344.5439515   7.2502357
2010-Sep-07 20:50 A   111.6122  20.8400 344.4578897   7.1319808
2010-Sep-07 21:00 A   113.7864  22.3893 344.3688247   7.0124955
2010-Sep-07 21:10 A   116.0124  23.9090 344.2767525   6.8916239
2010-Sep-07 21:20     118.2942  25.3957 344.1816604   6.7692317
2010-Sep-07 21:30     120.6361  26.8455 344.0835297   6.6451990
2010-Sep-07 21:40     123.0418  28.2546 343.9823378   6.5194157
2010-Sep-07 21:50     125.5153  29.6189 343.8780594   6.3917785
2010-Sep-07 22:00     128.0600  30.9340 343.7706675   6.2621879
2010-Sep-07 22:10     130.6790  32.1954 343.6601341   6.1305470
2010-Sep-07 22:20     133.3748  33.3983 343.5464307   5.9967602
2010-Sep-07 22:30     136.1495  34.5378 343.4295284   5.8607319
2010-Sep-07 22:40     139.0041  35.6087 343.3093985   5.7223661
2010-Sep-07 22:50     141.9390  36.6059 343.1860127   5.5815653
2010-Sep-07 23:00     144.9532  37.5240 343.0593427   5.4382308
2010-Sep-07 23:10     148.0445  38.3579 342.9293609   5.2922613
2010-Sep-07 23:20     151.2093  39.1023 342.7960402   5.1435535
2010-Sep-07 23:30     154.4428  39.7524 342.6593537   4.9920011
2010-Sep-07 23:40     157.7382  40.3033 342.5192754   4.8374948
2010-Sep-07 23:50     161.0876  40.7509 342.3757795   4.6799221
2010-Sep-08 00:00     164.4813  41.0914 342.2288406   4.5191669
2010-Sep-08 00:10     167.9087  41.3217 342.0784338   4.3551094
2010-Sep-08 00:20     171.3578  41.4393 341.9245343   4.1876259
2010-Sep-08 00:30  t  174.8162  41.4425 341.7671175   4.0165884
2010-Sep-08 00:40     178.2708  41.3306 341.6061590   3.8418648
2010-Sep-08 00:50     181.7088  41.1035 341.4416343   3.6633181
2010-Sep-08 01:00     185.1175  40.7621 341.2735185   3.4808067
2010-Sep-08 01:10     188.4850  40.3080 341.1017867   3.2941841
2010-Sep-08 01:20     191.8006  39.7435 340.9264134   3.1032984
2010-Sep-08 01:30     195.0545  39.0718 340.7473726   2.9079923
2010-Sep-08 01:40     198.2387  38.2962 340.5646376   2.7081031
2010-Sep-08 01:50     201.3463  37.4208 340.3781809   2.5034621
2010-Sep-08 02:00     204.3724  36.4499 340.1879742   2.2938945
2010-Sep-08 02:10     207.3130  35.3880 339.9939882   2.0792195
2010-Sep-08 02:20     210.1660  34.2399 339.7961928   1.8592497
2010-Sep-08 02:30     212.9301  33.0101 339.5945573   1.6337915
2010-Sep-08 02:40     215.6053  31.7035 339.3890504   1.4026444
2010-Sep-08 02:50     218.1925  30.3245 339.1796409   1.1656015
2010-Sep-08 03:00     220.6934  28.8777 338.9662985   0.9224495
2010-Sep-08 03:10     223.1103  27.3674 338.7489949   0.6729691
2010-Sep-08 03:20     225.4459  25.7977 338.5277061   0.4169354
2010-Sep-08 03:30     227.7033  24.1724 338.3024153   0.1541195
2010-Sep-08 03:40     229.8858  22.4953 338.0731180  -0.1157099
2010-Sep-08 03:50     231.9970  20.7700 337.8398293  -0.3927832
2010-Sep-08 04:00     234.0404  18.9996 337.6025971  -0.6773244
2010-Sep-08 04:10     236.0198  17.1875 337.3615226  -0.9695419
2010-Sep-08 04:20     237.9386  15.3366 337.1167965  -1.2696129
2010-Sep-08 04:30     239.8004  13.4500 336.8687648  -1.5776535
2010-Sep-08 04:40     241.6087  11.5309 336.6180543  -1.8936630
2010-Sep-08 04:50     243.3668   9.5829 336.3658318  -2.2174072
2010-Sep-08 05:00 A   245.0779   7.6106 336.1143867  -2.5481574
2010-Sep-08 05:10 A   246.7451   5.6213 335.8686046  -2.8840315
2010-Sep-08 05:20 A   248.3714   3.6299 335.6402501  -3.2200863
2010-Sep-08 05:30 A   249.9595   1.6739 335.4622419  -3.5420167
$EOE
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Column meaning:

TIME

 Prior to 1962, times are UT1. Dates thereafter are UTC. Any 'b' symbol in
the 1st-column denotes a B.C. date. First-column blank (" ") denotes an A.D.
date. Calendar dates prior to 1582-Oct-15 are in the Julian calendar system.
Later calendar dates are in the Gregorian system.

 The uniform Coordinate Time scale is used internally. Conversion between
CT and the selected non-uniform UT output scale has not been determined for
UTC times after the next July or January 1st.  The last known leap-second
is used over any future interval.

 NOTE: A time-zone correction has been requested. See header.

 NOTE: "n.a." in output means quantity "not available" at the print-time.

SOLAR PRESENCE (OBSERVING SITE)
 Time tag is followed by a blank, then a solar-presence symbol:

 '*'  Daylight (refracted solar upper-limb on or above apparent horizon)
 'C'  Civil twilight/dawn
 'N'  Nautical twilight/dawn
 'A'  Astronomical twilight/dawn
 ' '  Night OR geocentric ephemeris

LUNAR PRESENCE WITH TARGET RISE/TRANSIT/SET MARKER (OBSERVING SITE)
 The solar-presence symbol is immediately followed by another marker symbol:

 'm'  Refracted upper-limb of Moon on or above apparent horizon
 ' '  Refracted upper-limb of Moon below apparent horizon OR geocentric
 'r'  Rise    (target body on or above cut-off RTS elevation)
 't'  Transit (target body at or past local maximum RTS elevation)
 's'  Set     (target body on or below cut-off RTS elevation)

RTS MARKERS (TVH)
 Rise and set are with respect to the reference ellipsoid true visual horizon
defined by the elevation cut-off angle. Horizon dip and yellow-light refraction
(Earth only) are considered. Accuracy is < or = to twice the requested search
step-size.

Azi_(r-appr)_Elev =
 Refracted apparent azimuth and elevation of target center. Corrected for
light-time, the gravitational deflection of light, stellar aberration,
precession, nutation and approximate atmospheric refraction. Azimuth measured
North(0) -> East(90)-> South(180) -> West(270) -> North (360). Elevation is
with respect to plane perpendicular to local zenith direction. TOPOCENTRIC
ONLY.  Units: DEGREES

r-ObsEcLon r-ObsEcLat =
 Observer-centered ecliptic-of-date longitude and latitude of the target
center's apparent position, corrected for light-time, the gravitational
deflection of light, stellar aberration and atmospheric refraction. The
ecliptic plane is the Earth's orbital plane at print time.  Units: DEGREES

Computations by ...
 Solar System Dynamics Group, Horizons On-Line Ephemeris System
 4800 Oak Grove Drive, Jet Propulsion Laboratory
 Pasadena, CA  91109   USA
 Information: http://ssd.jpl.nasa.gov/
 Connect    : telnet://ssd.jpl.nasa.gov:6775 (via browser)
 telnet ssd.jpl.nasa.gov 6775    (via command-line)
 Author     : Jon.Giorgini@jpl.nasa.gov

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