How to develop trajectory for Chelyabinsk Meteor

[darius]

Could you tell me how to develop trajectory for the Chelyabinsk Meteor,
video recorded by a number of peers at geolocations based on the following compilation of videos
to work for Celestia ?

Compilation of recorded videos of the Chelyabinsk Meteor
http://www.youtube.com/watch?v=7Ce6Pk_0 ... r_embedded

[selden]

None of us have enough information to do that.

I saw a brief TV program about it. The people who determined the orbit had to travel to the locations where the videos were recorded in order to get enough information about where the cameras were pointed before they could do the necessary calculations.

[darius]

thanks,
does it mean this trajectory can be downloaded from a known web page
and installed in Celestia to be verified against registered videos ?

[abramson]

Hi. I have made an ssc file for the computed trajectory of the Cheliabinsk meteoroid. The orbit was calculated by Jorge Zuluaga et al., using geometrical analysis of the videos. His results appeared in the arxiv of physics preprints, but I used an update found at his webpage: FACom.

The result is rather good, even if the intersection of the orbits is not perfect. Here it is for anyone interested. If you happen to have a better orbit, please comment. I included a couple of screen captures in the zip. Place the ssc anywhere within Celestia's extras folder and Celestia will find it. Search for "Chelya" and you will find it. Time of the meteor was 2013-02-15 03:20:00 UT (I set an "Ending" specification for it).

Guillermo

[abramson]

I made a short video showing the last half orbit of the Chelyabinsk meteor and its fall over Chelyabinsk. I very small retouch of Zuluaga's mean orbital data, within their standard deviations, was enough to have it falling in the right place. Enjoy!

Guillermo

http://youtu.be/HaBIxLFI-Yo

[t00fri]

Great video, Guillermo!

F.

[Chuft-Captain]

Yes,

Great video Guillermo. You've obviously put a lot of effort into that.

I downloaded your addon, but unfortunately I've not been able to replicate the accuracy of the trajectory that you obviously were able to in the making of this video. (Not quite as exciting as I expected! )
In my Celestia, at the time of impact the asteroid is still at least 10,000 km from Earth when it disappears. Did the ZIP file include the aforementioned "retouch of Zuluaga's mean orbital data"?

CC

[abramson]

I downloaded your addon, but unfortunately I've not been able to replicate the accuracy of the trajectory that you obviously were able to in the making of this video.

Sorry, the uploaded addon contains just the published elements. As you notice, I had to tweak them to make the orbit intersect the Earth at the right place. Find them below.

I have to mention (in case it's needed) that there is no atmospheric slowing down. The orbit is just a Keplerian ellipse. Zuluaga made a many-body integration to compute osculating elements at different epochs, but it's difficult to match them in Celestia, so I didn't bother. As it is, it's enough for illustrative purposes. Also, the final 1000 km should need a sampled orbit since it's not elliptical at all.

These are the elements I used in the video. Use at wil:

Code: Select all

#-------------------------------------------------------------------------------
Location "Chelyabinsk" "Sol/Earth"
{
LongLat [ 61.375833 55.154722 0 ]
Importance 400
Type "City"
}
#-------------------------------------------------------------------------------
# THIS ONE IMPACTS SOUTH OF CHELYABINSK VERY CLOSE TO T0
"Chelyabinsk meteoroid (based on Zuluaga march 31 t0)" "Sol"
{
  Class "asteroid"
  Mesh "asteroid.cms"
  Texture "asteroid.jpg"
  Radius  0.0095 # diam. ~19 meters
#  Begining
#  Ending           # Time of impact was 2013-02-15 03:20:00 UT = 2456348.638889
  EllipticalOrbit   # Osculating elements at t0
  {
     Epoch       2456338.639279 # t0 as specified by Zuluaga 2013-02-15 03:20:33 UT
     SemiMajorAxis     1.60856214  # a
     Period            2.040124935402528774730728582932  # a^(3/2)
     Eccentricity      0.5854550   # e (0.585459704)
     Inclination       12.9692066  # i (10.9692066)
     AscendingNode    326.431364   # \Omega
     ArgOfPericenter   96.888      # \omega
     MeanAnomaly       23.5382     # M (23.5373425)
  }
  Albedo            0.2    # rock
  RotationPeriod    0.25   # guess
}
#-------------------------------------------------------------------------------