[meteorite-list] Trajectory comparison of 2012 DA14 and Russian meteor

From: Rob Matson <mojave_meteorites_at_meteoritecentral.com>
Date: Sat, 16 Feb 2013 10:52:41 -0800
Message-ID: <000001ce0c76$cccd1670$66674350$_at_cox.net>

Hi Mike/Bjorn/List,

Esko, Bill Gray and I exchanged a number of e-mails amongst each other yesterday
and early today discussing the Russian meteor trajectory. From the perspective
of
the earth, the two trajectories to first order are nearly perpendicular to each
other.
So that is pretty much end-of-story for any dynamical linkage between the
Russian
meteor and 2012 DA14.

Esko has since revised his estimate of the approach azimuth by a few degrees,
resulting in a lower velocity for the Russian meteor -- and getting closer to
the
minimum velocity possible. Unfortunately, the chances of precovery observations
of the small asteroid are pretty much zero due to the low solar elongation.
About
the only hope of a precovery observation would be if the elongation was low
enough that the object was within SOHO LASCO C3's field of view roughly a
day before impact. But even if it was, I doubt it would have been anywhere
near bright enough for LASCO to detect due to its small size and extremely
poor phase angle. --Rob

-----Original Message-----
From: meteorite-list-bounces at meteoritecentral.com
[mailto:meteorite-list-bounces at meteoritecentral.com] On Behalf Of Mike Hankey
Sent: Saturday, February 16, 2013 10:39 AM
To: Bjorn Sorheim
Cc: meteorite-list at meteoritecentral.com
Subject: Re: [meteorite-list] Russia mega meteor and asteroid 2012DA14 related,
yes I think so...

Esko posted these yesterday on meteor obs. This is estimated. The
wired article said it used SETI results.

Using mainly the video:
http://www.youtube.com/watch?v=4ZxXYscmgRg
and the weather satellite image, with no real good calibrations, I get a
rough solar system orbit ( the last stage by means of Marco Langbroek
Excel sheet).


( Entry with velocity 17 km/s ( 17.3) from about az. 97 with the slope
of 18 deg. Corresponding (luminous) start heigth (assumed, quite heigh
for the velocity, but considers very big size) 100 km and the end 7+ km.)
a=1.66
e=0.52
q=0.80 AU
aphelion at 2.53 AU
node=326.43 ( J2000.0 )
arg peri=116.0
i=4.05
43.6 days after perihelion
The geocentric radiant is 338, +2
This is only of very general quality and given with (a lot) too many
decimals.

The orbit does not much resemble the 2009 Feb, 16 innish fireball that I
told of yesterday.

According to that solution, the landing site would be not much more than
30 km away from that video recording site. But I do not know the
coordinates of this, except very roughly.
There quite probably are a lot of small fragments fallen down much
earlier along the track, (with possibly a number of bigger ones,
besides the main piece).

Esko




On Sat, Feb 16, 2013 at 1:35 PM, Bjorn Sorheim <astrogeo at online.no> wrote:
>
> Where are these elements posted??
> It's impossible that they could be as different as you state here.
> My mailbox got full yesterday, so if they have been posted on this list
> while I could not receive any new messages, I must apologize.
> But if not, post the elements or supply a link.
> It is interesting to note that NASA have not issued any stronger comment
> than they did yesterday.
> I am also surprised that good elements, as your anwer would indicate,
> could be computed the same day they first occured. Not a thing of earlier
> days
> such an achievement.
>
> The professor of astrophysics and celestial mechanics is a highly competent
> guy,
> therefore NASA used him.
>
> Bj?rn S?rheim
>
>
>
>>I'm talking about two different trajectories. Different inclinations,
>>different semimajor axes, (very) different eccentricities, (very)
>>different geocentric velocities. There is no plausible mechanism for
>>ending up with two pieces of the same body in such radically different
>>orbits- it would require first separating them, and then subjecting each
>>to a different history of three-body interactions.
>>
>>If the "foremost" celestial mechanics expert in your country says the
>>two are similar, he is not competent. I don't notice him speaking out.
>>
>>Chris
>>
>>*******************************
>>Chris L Peterson
>>Cloudbait Observatory
>>
>>
>>On 2/15/2013 11:35 PM, Bjorn Sorheim wrote:
>>>
>>> Two completely different trajectories??
>>> What the heck are you talking about?
>>> They are quite similar. It would not at this point say they are
>>> identical.
>>> In WHAT way are they _completely different_, elaborate please.
>>> And don't be so d** arrogant, for christ sake.
>>> I could mention that the foremost celest mechanican in my country says
>>> they
>>> are strangly similar, and he has been working for NASA and the Voyagers,
>>> and he has
>>> an asteroid named after him.
>>>
>>> Bj?rn S?rheim
Received on Sat 16 Feb 2013 01:52:41 PM PST