[neo_followup] Improved 1964-054A = OGO-1 data, ephems

[Francisco Ocaña González]

Hello Bill,

regarding the 1972 fireball, it seems the meteoroid is still out
there: https://ui.adsabs.harvard.edu/abs/1994A%26A...283..287C/abstract.

Indeed most of them do not lose enough energy to get into a geocentric
orbit. Even more, some geometry encounters are lucky enough to put
them in a larger orbit (e.g., this recent fireball
https://iopscience.iop.org/article/10.3847/1538-3881/ab8002/pdf btw,
nice paper, including review of grazing fireballs).

And following the topic, another relevant papers on how these grazing
fireballs end up in JFC orbits:   https://arxiv.org/pdf/2008.08848.pdf

Regards,

Paco

El jue., 27 ago. 2020 a las 17:30, Bill Gray
(<pluto at projectpluto.com>) escribió:
>
> Hello all,
>
>     I found quite a bit of additional data for this object in
> my inbox this morning (thank you!).  At present,  I've got
> 46 observations from the current orbit :
>
> https://www.projectpluto.com/temp/ogo1.txt
>
>     A correction to my previous e-mail : you can just download
> the above file and feed it into Find_Orb,  either "current"
> Windows or Linux,  or on-line,  or the old Windows GUI version,
> and compute ephemerides for your location that should be good
> to within a few arcminutes.  That's about the level of effect
> I expect the upcoming perigee (occurring as I write) to have.
>
>     You can still turn on solar radiation pressure (by hitting
> the '*' key) and constrain the area/mass ratio to be A=0.03,
> and get suitably adjusted results.  But unless you have a
> small field of view,  the non-SRP version should at least let
> you find the object.
>
>     The good news is that,  if the nominal AMR makes a five
> arcminute difference (300") and the object is measured to an
> arcsecond,  it means the effects of atmospheric drag during
> that pass will be measured to about one part in 300.  Which
> is pretty good.  And we'll probably get enough data to
> _really_ nail down the re-entry time and location.
> (Currently looks to be at about 21:00 UTC on the 29th over
> French Polynesia,  but a little more or less drag could
> make that prediction look stupid.)
>
>     This may be a useful exercise to prepare for something
> like the 1972 fireball that zipped through the atmosphere,
> lost lots of speed,  and probably was left in Earth orbit
> and crashed at the next perigee.
>
> -- Bill
>
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