From past experience, I would wait until nearer the desired observing date to update the orbital elements. I missed a close approach by about 20 arcmin last year by having slightly older elements loaded into Guide...it simply hadn't occurred to me they would change quite so much during a close pass.

Unless I'm mistaken, any published elements right now will be for the "current" solar orbit. As a body nears Earth, that orbit will begin to change more rapidly. I would assume with a small body and a relatively close pass, 2012DA14 will exhibit more change than most.


Grant

--- In guide-user@yahoogroups.com, "Adam" wrote:
>
> Hi
>
> Add this line to usrcomet.txt and +1 tu number on top
>
> 2012 DA14 15.809604 2 2013 0. 0.00022798 4.2292420 86.211283 354.074027 175.058537 2000. 24.36 .15 A Center: 3
>
> Take a look to
> http://tech.groups.yahoo.com/group/guide-user/message/9270
>
> replace link in message from
> http://www.projectpluto.com/temp/usrcomet.htm
> to
> http://www.projectpluto.com/temp/usrcomet.txt
>
> You can also correct this elements data using HORIZONS/JPL
> sets Geocenter , reference plane at Earth mean equator and time at close encounter.
>
> You can do that also using e-mail, send this
>
> !$$SOF
> COMMAND= 'DES=2012 DA14'
> CENTER= '500@399'
> MAKE_EPHEM= 'YES'
> TABLE_TYPE= 'ELEMENTS'
> START_TIME= '2013-02-15.809604'
> STOP_TIME= '2013-02-16.809604'
> STEP_SIZE= '1 h'
> OUT_UNITS= 'AU-D'
> REF_PLANE= 'FRAME'
> REF_SYSTEM= 'J2000'
> TP_TYPE= 'ABSOLUTE'
> ELEM_LABELS= 'YES'
> CSV_FORMAT= 'NO'
> OBJ_DATA= 'YES'
> !$$EOF
>
> to horizons@... and subject: BATCH-LONG
> Email must be in plain text
>
>
> Adam
>
> --- In guide-user@yahoogroups.com, "pastorgalactico" wrote:
> >
> > I would like to see the 2012 DA14 for February 15 and would like to know how to put this asteroid ephemeris GUIDE 9 Most Successful possible then.
> >
> > regards
> >
>