Asteroid observer finds object beyond Moon

From: Tony Beresford (aberesford@iprimus.com.au)
Date: Tue Sep 10 2002 - 07:29:50 EDT

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    Mr Bill Yeung, a well equipped amatuer astrometrist has found an object in
    Earth orbit. From his own and other observers measurements over 3 days
    here are the orbital elements, derived using the orbfit programme 
    associated with the planetarium/charting programe Guide 8.
    J002E3 is the temporary designation assigned by the observer.
    As this isnt in orbit around the Sun, this hasnt been replaced 
    by a designation, as is usually the case.
    
    Orbital elements relative to the Earth
    19002 143
       Perigee 2002 Aug 12.242364 TT
    Epoch 2002 Sep  3.0 TT = JDT 2452520.5
    M 158.25875              (2000.0)            P               Q
    n   7.27371087     Peri.  197.86606     -0.89385997      
    0.44471372     
    a  568562.564 km   Node     9.18081     -0.35532406     -
    0.62519113     
    e   0.4547354      Incl.   20.91490     -0.27342119     -
    0.64137801     
    P  49.49d           H   26.0           G   0.15      q 310016.997 km
    From 39 observations 2002 Sep. 3-6;   RMS error 1.054 arcseconds
    To summarize, its motion is currently such that its orbiting the Earth
    about every 50 days, at distances varying from 310,000Km to 847,000Km
    On september 6, it was about mag 16( see observation reports)
    
    On  temporary basis this object has been added to the spacecraft list
    on the JPL Horizons system. Observations should be reported to
    the Minor planet Center ( mpc@cfa.harvard.edu ) and to Paul Chodas
    at JPL( paul.chodas@jpl.nasa.gov ) , whose quick and decisive action is to be applauded
    -----------------------------------------------------------------------
    The unusual object J002E3, formerly on the Minor Planet Center NEO
    confirmation page, has been loaded into our Horizons system so that
    interested observers can generate ephemerides.  Our latest orbit
    solution shows that the object is in a loosely bound orbit about the
    Earth, with a period of about 50 days.  This leads us to believe the
    object is a spacecraft or rocket body, but it has not been associated
    with any known launch.  Further observations of the object are highly
    desirable to help characterize the nature of the object: we will
    update our orbit solution as they become available.
    
    Telnet and email users of Horizons can access this object by typing
    "J002E3".  Web users of Horizons can access the object by going to
    the Major Body Menu, selecting the Spacecraft list, and choosing the
    entry "J002E3 Spacecraft (UNCONFIRMED)".  The available time span is
    currently August 1 through December 1, 2002.  The telnet address of
    Horizons is telnet://ssd.jpl.nasa.gov:6775, and the web address is
    <http://ssd.jpl.nasa.gov/cgi-bin/eph>.
    =====================================================================
    A further comment about the recent behaviour of this object. The discoverer
    was amazed that it hadnt been observed sooner. Dr. Chodas's comments give
    a plausible explanation .
    
    ------------------------------------------------------------------------
    I agree that the chance of J002E3 being a captured NEA is small,
    but its orbit is _consistent_ with a captured NEO.  Running our
    nominal orbit solution backwards, I calculate that the object
    passed through the opposition point only once, around June 17, at
    just over one half a lunar distance and a skyplane rate of about
    100 arc-sec per minute.  (Would the surveys have found it at that
    rate?)  Our best orbit solution indicates that the object was
    likely captured from heliocentric orbit during the April/May time
    period, as it passed through the L1 Lagrange point between the
    Earth and the Sun.  (These calculations all assume just the nominal
    set of asteroidal perturbations; perturbations which might be
    important for a man-made object are neglected.)
    
    Another point: even if the object was captured from heliocentric
    orbit, that doesn't mean it is asteroidal: it could for example be
    a rocket stage escaped from an earlier cis-lunar orbit.
    
    We may never know what this object is, but a longer astrometric
    data arc may help narrow down the possibilities.  Perhaps our best
    hope, if we get an accurate enough orbit, is to observe the object
    with radar.
    ==================================================================
    
    
    Here are the observation, as reported to the Minor Planet Center, in their
    standard format, to which I have added column headings. 
    TEL 0.45-m  Schmidt-Cassegrain + CCD
    NET GSC-ACT
         Object ID Year MM dd.ddddd   RA           Dec               Magn.      Obs code
         J002E3 * C2002 09 03.32505 01 13 42.12 +03 12 16.3          16.7 V      G78
         J002E3   C2002 09 03.33734 01 13 44.81 +03 13 08.8          16.7 V      G78
         J002E3   C2002 09 03.34919 01 13 47.21 +03 13 58.7          16.7 V      G78
         J002E3   C2002 09 05.98163 01 43 42.15 +05 55 00.5                d     557
         J002E3   C2002 09 05.98245 01 43 42.36 +05 55 03.4                d     557
         J002E3   C2002 09 05.98326 01 43 42.62 +05 55 06.4                d     557
         J002E3   C2002 09 05.98409 01 43 42.89 +05 55 10.1                d     557
         J002E3   C2002 09 05.98490 01 43 43.13 +05 55 13.5                d     557
         J002E3   C2002 09 05.98572 01 43 43.37 +05 55 16.8                d     557
         J002E3   C2002 09 05.98653 01 43 43.63 +05 55 19.7                d     557
         J002E3   C2002 09 05.98735 01 43 43.88 +05 55 23.3          16.9 Vd     557
         J002E3   C2002 09 05.98816 01 43 44.12 +05 55 26.8                d     557
         J002E3   C2002 09 06.00044 01 43 47.68 +05 56 15.5                d     557
         J002E3   C2002 09 06.00422 01 44 10.69 +05 59 26.6          16.0 Rd     946
    
         J002E3   C2002 09 06.00792 01 43 49.76 +05 56 45.1                d     557
         J002E3   C2002 09 06.00792 01 44 11.64 +05 59 41.4          16.0 Rd     946
    
         J002E3   C2002 09 06.01284 01 44 12.91 +06 00 01.8          16.1 Rd     946
         J002E3   C2002 09 06.01444 01 43 51.51 +05 57 10.5                d     557
         J002E3   C2002 09 06.01625 01 43 59.47 +05 56 42.3          16.4 Rc     636
         J002E3   C2002 09 06.01796 01 44 00.13 +05 56 48.8          16.5 Rc     636
         J002E3   C2002 09 06.02139 01 44 01.07 +05 57 03.0          16.3 Rc     636
         J002E3   C2002 09 06.02190 01 43 53.48 +05 57 39.7                d     557
         J002E3   C2002 09 06.02310 01 44 01.60 +05 57 08.8          15.8 Rc     636
         J002E3   C2002 09 06.03127 01 43 55.88 +05 58 15.9                d     557
         J002E3   C2002 09 06.03774 01 44 16.71 +06 02 14.9          16.8 Rm     620
         J002E3   C2002 09 06.03780 01 43 57.52 +05 58 40.9                d     557
         J002E3   C2002 09 06.04197 01 44 17.51 +06 02 32.2          16.8 Rm     620
         J002E3   C2002 09 06.04340 01 43 58.88 +05 59 02.3                d     557
         J002E3   C2002 09 06.04513 01 44 18.13 +06 02 45.1          16.4 Rm     620
         J002E3   C2002 09 06.04838 01 44 18.75 +06 02 57.0          16.6 Rm     620
         J002E3   C2002 09 06.05661 01 44 02.09 +05 59 52.0                d     557
         J002E3   C2002 09 06.06127 01 44 03.17 +06 00 09.3                d     557
         J002E3   C2002 09 06.23925 01 47 01.69 +06 14 19.2          16.0 Rc     649
         J002E3   C2002 09 06.24060 01 47 02.13 +06 14 25.1          15.9 Rc     649
         J002E3   C2002 09 06.24250 01 47 02.75 +06 14 33.1          15.8 Rc     649
         J002E3   C2002 09 06.24449 01 47 03.43 +06 14 41.8          15.9 Rc     649
         J002E3   C2002 09 06.41722 01 47 38.42 +06 25 48.5          16.1 Rd     734
         J002E3   C2002 09 06.41924 01 47 38.70 +06 25 54.6          16.2 Rd     734
         J002E3   C2002 09 06.42271 01 47 39.24 +06 26 05.9          16.1 Rd     734
    G78 is Bill Yeung Desert Wanderer Obs
    557 is Ondrejov in Czechia
    946 is Jamie Nomen ( Ametella de Mar )
    636 is Essen 
    620 is Mallorca, Spain
    649 is Powell Obs Louisburg Kansas
    734 is Farpoint obs, Eskridge, Kansas
    Of these sites only 557 are professional astronomers
    
    
    
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