grantcblair May 24, 2013
--- In find_orb@yahoogroups.com, "Glen Deen" <glen.deen@...> wrote:
>
> Is this topic appropriate for this group? Maybe so if you read my last
> paragraph.
>
> An Australian friend of mine asked me:
>
> "I was amazed that there was no heads-up on the
> meteorite that struck in Russia recently.
> Is NORAD not able to track these?"
>
> I found these articles using Google. My friend could have found them too.
> http://ogleearth.com/2013/02/reconstructing-the-chelyabinsk-meteors-path-wit
> h-google-earth-youtube-and-high-school-math/
> http://www.technologyreview.com/view/511691/astronomers-calculate-orbit-of-c
> helyabinsk-meteorite/
> And this paper.
> http://arxiv.org/abs/1302.5377
>
> As I understand it, the authors of that paper used NOVAS to calculate the
> orbit.
> Couldn't they just as well have used Find_Orb?
>
> How did this meteorite sneak up on us without having been observed while
> inbound?
>
> With a direct orbit, I think it should have been observable after sunset
> while
> it was inbound. Has anybody calculated its proper motion relative to its
> radiant
> position in the sky? Was it too small for the motion to be noticed?
>
> Would I be wasting my time if I used Find_Orb to study this question? I
> would
> attempt to compute the proper motion of this body as a function of time over
>
> many days while it was inbound to start with. Then I would use Guide to plot
>
> the incoming radiant in the field of stars to see if there is any bright
> star nearby
> that would hide this object in its glare. If so, that might be considered
> to be an
> observation over several days at the same position. Then I might look at how
>
> sensitive the displacement from that radiant was to variations in each of
> the
> heliocentric orbital elements. Does any of that sound feasible to you?
>
> -Glen
>