Reconstructing the Chelyabinsk meteor’s path, with Google Earth, YouTube and high-school math

[March 2: Read the follow-up article, Comparing paths with the pros in Google Earth]

[March 9: Read the follow-up article, Three trajectory models of the Chelyabinsk meteoroid compared]

[April 5: Help scientists to more accurately calculate the trajectory. Visit www.russianmeteor2013.org to contribute videos or help with the analysis.]

Like many others, I was absolutely astounded by the meteor strike over Chelyabinsk when I woke on Friday morning. One silver lining to our self-surveilling society is that an event of this magnitude is certain to get caught on the myriad of always-on dash- and webcams. I for one could not get enough of the videos.

Might it be possible to use this viral footage with Google Earth to have an initial go at mapping the meteorite’s trajectory? I was pondering this question some 2,500km away from Chelyabinsk when I chanced upon this video:

That place is easy to find — it’s Revolution Square at the absolute center of Chelyabinsk, looking almost directly south. It is also easy to measure — the distance between the two central light poles is 32 meters, as per a quick measurement in Google Earth, while the five lanes of traffic going right to left (west to east) measure 19 meters. From this it is easy to estimate the height of the light poles to be around 12 meters — an estimate corroborated by numerous panoramas in Google Earth showing people next to these lamp posts, giving us added data points.

Using all this information, I was able to do some image analysis in Photoshop on the lengths and angles of the shadows as the meteor streaked across the sky. Here’s an animated gif showing the result of that:

gif-animation-small

The ensuing grade-school mathematics (SOHCAHTOA!) resulted in three lines of sight at three instants a few seconds apart. (For the sake of the record, I roughly calculated them to be towards 122 degrees at an inclination of 33 degrees at 9:20:28.7, towards 187 degrees at an inclination of 40 degrees at 9:20:32.2, and towards 222 degrees at an inclination of 32 degrees at 9:20:33.4. These times are the video’s own timeline, though they appear to correlate closely with the timelines of other videos.)

This allowed me to draw an inclined plane in Google Earth that should include the meteor’s path, though it does not allow me to know the distance of the meteor from central Chelyabinsk, nor its speed.

meteorgeview

However, we have more clues. We know a fragment of the meteor landed in Lake Chebarkul, roughly 70km WSW of Chelyabinsk. Gratifyingly, the inclined plane generated from the above video intersects with the crash site. Also useful was the estimate by the Russian Academy of Sciences that the meteorite hit the Earth’s atmosphere at around 50,000 km/h, shattering at an altitude of 30-50km. If that was the rough speed of the meteor as it burned up in the video, then the 4.7 seconds between the first and last shadow measurements would have seen it travel 65 km. Fitting a 65km line between these two lines of sight allows us to draw a straight line path for the meteor towards the crash site, with the first measured time yielding a height of 29km, which is the moment the meteor first brightened enough to give a clear shadow.

Download the visualizations for this as a KMZ file to open in Google Earth. Do play with the opacity slider of the overlay to check the alignments yourself — it’s most of the fun.

Screen Shot 2013-02-16 at 16 Feb 02.07.21 CET

How does this data square with the Meteosat 9 image that has being doing the rounds? At first glance, not well: Overlaying the image in Google Earth and aligning the border with Kazakhstan shows a 240km contrail that appears to end some 75km to the ENE of Chelyabinsk, even though the path when traced on the ground also leads directly to Lake Chebarkul.

At first, I thought the image might have been taken 5 minutes earlier, before the meteor streaked straight across Chelyabinsk proper, because the image’s metadata gives us a time of 3:15:00Z, or UTC, which is 6 hours behind Chelyabinsk time. But no meteor is going to take 5 minutes to traverse 75km, so we’ll just have to live with the time discrepancy. Webcams are not atomic clocks.

Much more interesting is the fact that if you look at the position of Meteosat 9, which is in a geostationary orbit, you see that Chelyabinsk is near the horizon of its view of Earth. This leads to extreme foreshortening in the snapshot of the meteor’s contrail:

Meteor vapour trail, 15th Feb 2013
(Notice the outline of the Sea of Azov in the foreground. Here is another version showing the thermal impact (source).)

The version used in the overlay is an enhanced view of this image, taken from the same angle. (The blacked-out upper right-hand corner of the overlay is behind the horizon as seen from Meteosat 9.). If you simulate this view of Chelyabinsk in Google Earth, you see that in fact, the contrail aligns quite nicely over Chelyabinsk considering that it would be 30km high and at such an extreme angle over the horizon. So the 4.7 seconds of maximal brightness (with contrail) do get to happen just south of Chelyabinsk proper, as per the above video, and without contradiction by Meteosat 9.

I feel this post would not be complete without some big caveats: I am not a trained scientist; I don’t know if meteors travel through the atmosphere in straight lines or at constant speeds (I assume they don’t, but that it doesn’t matter for back-of-the-envelope type calculations). Still, it is satisfying to know that with judicious use of Google Earth, YouTube and Photoshop you can get quite far in the meteor simulation game. I can’t wait to see what the professionals come up with.

UPDATE 2013-02-16: Via SebastienP in the comments comes another triangulation, comparing the calculated path from the KMZ file with the view from another dash cam. It holds up pretty well!

stefangeensreconstituti

(Source)

UPDATE 2013-02-17: In this comment, some smart calculations by Sean Mac are confirmed by a video he’s found showing the contrail crossing almost exactly above the southern suburb of Yemanzhelinsk. I found the exact vantage point of the video he references in Google Earth by connecting this Panoramio photo to this view in the video.

This suggests the meteor’s trajectory towards Earth was higher and steeper along the inclined plane of sight derived from the central Chelyabinsk vantage point than the initial calculation suggested. That’s not surprising, as that calculation was based on an initial estimate of the velocity by the Russian Academy of Sciences, which now appears to have been on the low side.

I’ve now added a second path for the meteor in Google Earth, together with the location of the vantage point in Yemanzhelinsk, in this KMZ file. Open it as a complement to the first KMZ file to see what I would consider to be an upper bound (green) for the trajectory along the same inclined plane, with a new likeliest path (red).

latestredline

“Looking up” in Google Earth from the vantage point in Yemanzhelinsk (I can because I have a 3D mouse from 3DConnexion), I get a very similar angle of view of the contrail when framed by the NNW axis of the buildings on that square.

abovehead

A further video showing the perspective from the town of Korkino further north (included in the new KMZ file) shows that the meteor passed a little to the south of there, allowing for a pretty accurate triangulation. (Thanks to Robin Whittle and liilliil in the comments for the heads up.)

UPDATE 2013-02-22: OK, so this is kind of special: An astrophysics paper has just been submitted to ArXiv.org that models the orbit of the Chelyabinsk meteor, referencing this blog post as a starting point: A preliminary reconstruction of the orbit of the Chelyabinsk Meteoroid by Jorge I. Zuluagaa and Ignacio Ferrin. Details are here, and here comes the resulting animation:

[March 2: Read the follow-up article, Comparing paths with the pros in Google Earth]

[March 9: Read the follow-up article, Three trajectory models of the Chelyabinsk meteoroid compared]

[April 5: Help scientists to more accurately calculate the trajectory. Visit www.russianmeteor2013.org to contribute videos or help with the analysis.]

374 thoughts on “Reconstructing the Chelyabinsk meteor’s path, with Google Earth, YouTube and high-school math”

  1. Stefan,
    This video I sent you earlier where the smoke trail seems to pass overhead is from Yetkul about 15km SE of Korkino.

    The video starts at this location
    http://www.wikimapia.org/#lat=54.8217&lon=61.5844&z=18&l=0&m=s

    It is interesting that 26 seconds into the video, the camera looks WNW, showing a tall tower and the smoke trail.

    If the smoke trail passed through the zenith, then a line drawn through the vertical axis of the tower, and a line drawn along the smoke trail, should intersect at the zenith.
    What is required is a photo montage joining the images together as the camera pans up along the smoke trail past the zenith to the ESE.
    Could you help with this please.

  2. Great article! Very interesting! I live in Chelyabinsk. Chelyabinsk residents have witnessed the historic event. It should be noted that at first we thought it was a terrorist attack, or a plane crash. The windows in homes, offices, shops, schools and hospitals were broken by the shock wave. Everyone was scared! We are all lucky!

  3. Stefan,
    If you look at the Yemanzhelinsk video http://www.youtube.com/watch?v=64gXz9W2oyQ
    A line drawn along the vertical axis of the light pole and a line drawn along the smoke trail diverge towards the zenith, making a large angle.
    Therefore the smoke trail passed well north of Yemanzhelinsk and not a little north as has been suggested.

    1. Agreed that the contrail passed north of Yemanzhelinsk, but we also know it passed south of Korkino – so my red line more or less splits the difference.

  4. Just 4 of the useful resources I have found online recently:

    *Interesting NYTimes article on variation in damage and infrasound discussion:
    In Russia, Ruins and Property Spared by Meteor, Side
    by Side
    http://www.nytimes.com/2013/02/18/world/europe/in-russia-property-ruined-and-spared-by-meteor-share-space.html

    *Attempted list of all video:
    http://www.webmasterworld.com/foo/4546400.htm

    *Attempted list of all unique/unedited video:
    https://web.duke.edu/isis/gessler/meteorites/chelyabinsk.htm

    *A very familiar sounding description of a meteor burst from 1642.
    http://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#.22Cannon_fire.22_following_meteorite_impacts
    “In an instant was heard first a hideous rumbling in the air, and presently after followed a strange and fearful peal of thunder; it maintained the fashion of a fought battle. It began thus: first, for an onset, went off one great cannon as it were of thunder alone, like a warning-piece to the rest that were to follow. Then, a little while after, was heard a second; until the number of 20 were discharged, or thereabout. In some little distance of time after this, was audibly heard the sound of a drum, beating a retreat. Amongst all these angry peals shot off from heaven, at the end of the report of every crack, a hissing noise made way through the air, not unlike the flying of bullets from the mouth of great ordnance, and by judgement were thunderbolts; for one of them was seen by many people to fall at a place called Bawlkin Green…” – anonymous leaflet on the Hatford meteorite fall of 1628

      1. Not meaning to go off topic, even a little bit, but reading about Phaëton there is a near perfect description of the February meteor:

        [from Wikipedia] . . .In Plato’s Timaeus, Critias tells the story of Solon’s visit to Egypt shortly after Solon was elected archon in 594 B.C. Solon was puzzled by the fact that the Greeks had no history prior to the Trojan War and told the Egyptians that history must begin with the first man (Phoroneus) and woman (Niobe) and after the Deluge with Deucalion and Pyrrha. To which the Neith priest, identified by Plutarch as Sonchis the Saite, said,
        …in mind you are all young; there is no old opinion handed down among you by ancient tradition, nor any science which is hoary with age. And I will tell you why. There have been, and will be again, many destructions of mankind arising out of many causes; the greatest have been brought about by the agencies of fire and water, and other lesser ones by innumerable other causes. There is a story, which even you have preserved, that once upon a time Paethon, the son of Helios, having yoked the steeds in his father’s chariot, because he was not able to drive them in the path of his father, burnt up all that was upon the earth, and was himself destroyed by a thunderbolt. Now this has the form of a myth, but really signifies a declination of the bodies moving in the heavens around the earth, and a great conflagration of things upon the earth, which recurs after long intervals.”

        A “declination of the bodies moving in the heavens around the Earth” – hmmm, now if the term “declination” is taken to mean “declining” certainly that is so, and if “around the Earth” means in the vicinity of, as in near earth objects, Sonchis was no dummy.

        This February one did not burn up all that was no the Earth, but the inability to drive them and the thunderbolt destruction – if this one hit 3 centuries ago or more, it would be a good description in non-technical terms. The meteor “came out of the sun” (one of the very first descriptions I read), and it careened across the sky, with billows VERY akin to dust behind a chariot, then died quickly after the thunderbolt hit it. All the elements are there.

        Ok, back on topic, now! Sorry!

        Steve Garcia

  5. To: Steve on February 20, 2013 at 08:11

    Can’t you see, that the pole is not straight? It is usual, that poles with electric cables attached, especially, when cable is only in on side, will get skewed.

  6. Thank you Kuuuurija.
    I must admit I did not pay much attention to the angle of the pole because the angle of the smoke trail was so far from vertical.
    If the smoke trail passed through the zenith then when viewed in the WNW it should have been exactly vertical.
    I should have explained that better.

  7. This is the video from Yetkul, that I posted earlier, that seems to show the smoke trail pass overhead.

    Looking both WNW and ESE the smoke trail appears vertical, which it must be to pass through the zenith.

    About 26 seconds into the video, the camera looks WNW, showing a tall tower and the smoke trail.

    To the right of the tall tower is a short tower.
    The google earth image dated June 2009 clearly shows both towers and their shadows, allowing the accurate location of the base of the towers.
    Tall Tower 54.82186ºN 61.57460ºE 232m
    Short Tower 54.82229ºN 61.57870ºE 228m
    Camera 54.82193ºN 61.58430ºE 230m

    Using a precision geodesic program
    Camera to Tall Tower Az 269.29ºT 624m
    Camera to Short Tower Az 276.36ºT 362m

    With these bearings I calculated the azimuth of the smoke trail from the video as 282.9º/102.9º.
    It is hopefully accurate within a few degrees, assuming the smoke trail passed through the zenith at Yetkul and that the smoke trail did not move far cross track between when it was made and when it was videoed.

    After I calculated the meteor azimuth I calculated
    Yetkul to Lake Chebarkul ice hole azimuth 282.0º 81.8km. A nice agreement.

    The sound delay recorded at Korkino (54.89070ºN,61.39898ºE) was 88 seconds.
    The track from Yetkul passes about 5km a little west of south from Korkino.
    Assuming the track at this point was nearly level, which it must have been for pieces to reach Lake Chebarkul, and using a 3 layer atmosphere model, I calculate the height of the sound source that reached Korkino was 26km.
    If the height of the tall tower was known the elevation of the last part of the smoke trail could be estimated.

    1. Steve –

      You don’t need the tower projected up to the zenith. You have in this video everything that is needed to extrapolate the meteor’s heading. . .

      . . .At 0:02 the view clearly shows the path of the object’s trail is very slightly to the left. The angle is not vertical, but slightly skewed. Ergo, this camera is NOT exactly under the trail.

      …At 0:09 this is repeated, so I can safely say that the trail – as observed – is slightly to the south of the camera.

      …At 0:25 the cameraman stops. He immediately points the camera at the building on the west side of the street. The trail is aligned with the center of the roof eave’s southern end. Almost.

      Still standing in that spot, he swings the camera overhead, along the trail, and stops at 0:26 (you have to be quick with the ) when he has the eastern end in view. Also in view is the roof of the house on the east side. The trail aligns about a foot to the left of the southern edge.

      . . .At 0:27 the east end of the trail aligns about 1 foot from the southern edge of the blue roof. The western end is about 1 meter east of the center of the southern edge of the roof of the long apt. building on the west side.

      The blue roof is 14 meters wide.

      The white roof is also 14 meters wide.

      So now we have a camera in one spot, underneath the trail, and it has both ends of the trail. Bingo!

      Now we just have to determine where he is. He is at 54°49’19.02″N 61°35’3.50″E, about 0.5 meter off the edge of the road. This can be determined by the views as he is walking.

      Lining up those two points, we draw a line. The E-W heading is 279.46°. I’d give that a +/- of 0.5° with a 75% certainty it is within 0.25°.

      Now, that heading worked back from Lake Chebarkul, using the end of the 2nd trajectory calcs above (the 1st doesn’t show an impact point), passes only 70 meters north of the cameraman.

      But north isn’t south. Why do the 0:02 and 0:09 views look like the trail is to the south a little bit?

      Issues:
      1. Time – We don’t know how soon afterward the cameraman got out there.
      2. Accuracy – I estimated the distances from the center of one roof and from the edge of the other. The two are less than 45 meters from each other, so extrapolating up to over 70 km will multiply any error by about 1500-fold.
      3. Wind – was the wind blowing out of the north, pushing the trail southward? If not, then I don’t know how to rectify these observations. So I have to posit that the wind WAS blowing that way.

      This heading is only 0.25° below the value of the first calcs above. So I am pretty confident of it.

      Steve Garcia

      p.s. IMHO the REAL problem is the transition from orbiting the Sun to that final heading at that location – latitude and longitude. I liken it to a really fast bug overtaking a bus from one side (the left one, I think) and then making a 90° right turn and going SPLAT! on the windshield halfway across and near the top of the glass. But this bug has no ability to maneuver on its own. Astronomers have done the easy parts – the flight as an Apollo and the final flight. But those two do not easily mesh, not at all.

      Right now I am thinking it had to have circled Earth more than once before entering the atmosphere. I can’t see how it could have gotten into THAT heading at the end, not from that starting orbital path.

  8. I updated my guesstimate: http://goo.gl/yd7Jk Added some orients, for explaining the azimuths. If you will find some errors (wrong location of a video, etc), or have idea of some good videos or photos that can improve my compilation, then let me know. Especially helpful would be videos and photos from behind the meteor, like from Troebratsky, Nikolaevka, Semipolka (KZ).

    1. Like that map with the vid/pics located to get a feel of the whole thing.
      Saw this one linked http://www.youtube.com/watch?v=iwkKvLf3fZE
      On the right hand side of the trail from the POV of the cam – the trail looks like the rock is skipping! and quite consistently too with three loops there. The meteor did the triple jump :) Should probably call it meteors because from the trail looks like there were were two paths at least. Anyway good map and hope more gets added to it.

      1. In another video shot from almost directly underneath, and with some close up shots, the main trail has what looks like a spiral or helix within it. Looks like the object was spinning very rapidly.

      2. To Gary,
        The video was taken some time after the meteor.
        You can see the dense part of the cloud has risen a long way like a mushroom cloud.
        The wiggles in the right hand side of the smoke trail are due to upper atmosphere winds distorting what was originally a straight line.

  9. BTW, does anybody knows was the exact position, course, altitude and speed ob the airplane, that was nearby at the moment of explosion? At least the Tower of Chelyabinsk Airport should know, as the plane was preparing to land there.

  10. Take in a view, that end point of trajectory line should not be land at Chebarkul pool – it should be higher and continue farther. There are only not very big pieces stopped by air friction. It is interesting, how far it is continuing without air friction.

  11. I am very interested whether you managed to get a precise information about the position of DMSP satellite, as well as about the correct way of projecting the satellite image onto the map.

    Also, do you possess a decent-quality version of that image? I only found these two images: http://phys.org/news/2013-02-colorado-state-university-scientists-visible.html and http://www.today.colostate.edu/story.aspx?id=8234 , both of which have relatively low resolution.

    1. Thanks to g1smd’s connection we might get some help on that. But perhaps it is good also to try directly through the colorado scientists. Sadly, I won’t have time the next 8hours.

    2. Hi penguinny, I’ve already asked the scientists from Colorado university. We might get some information.

    1. Wow, that one photo with the full fresh contrail should go on to win all kinds of international photo prizes. Stunning.

  12. This seems to be one of the better videos to capture the multiple bangs from the event. http://www.youtu.be/gQ6Pa5Pv_io The sound is a bit dampened by being inside a vehicle, however you can see the sound visibly shakes the vehicle a few times. Shame about the car alarm sounding over the first part.

    This one too for sounds: https://www.youtu.be.com/efvP-RRuJuA
    There are deep shadows in the car park but doesn’t look like anything that can be measured for distance.

  13. For ssvilponis
    Troitsk car camera
    54.07707ºN
    61.53128ºE
    bearing of Vanishing point
    329.0º
    using full resolution and full screen

  14. Interesting CCTV video with some fragments falling down:

    http://www.youtube.com/watch?feature=player_embedded&v=ZzwB7FeJRgA

    The poster politely refused to provide the location, so I guess it’s a high security object like military base, depot or something nuclear related. So I found a military base and a security wall resembling what is on the video at 54.99633, 60.74004 but some features on the video do not match, so I don’t think the camera is there. Can you, the shadow specialists, calculate approximate location of the camera and the bearing of the wall?

    1. Hi Serge, if the updated kmz from Stefan is accurate, and considering the almost abscence of shadow at the pole’s foot, I’d say the barrier’s orientations in the village of Sart-Abdrashevo match pretty well the video. It’s at 54.778019,62.247326

    2. Serge –

      First off, NICE video! It could be used to find meteorites.

      I got it the location of the camera for you.

      The fence alignment matches, and the tanks on the right match. The pipeline you see in the distance diving under the fence, with another pipeline beyond. I even can see the pole the camera is mounted on. It is at 54°50’56.53″N 61°33’15.14″E.

      It is a facility just NW of the town of Yetkul/Etkul/Etcul.

      Based on the angle of the flight, it had to be very near – but slightly to the right – of the flight. The object passed overhead just to the left, but finished to the right. So, the fence had to have an alignment essentially E-W. I tracked back along the right edge of the first trajectory calcs (above) on GE.

      It was farther back than I’d thought. But by backing out and getting a low perspective that was close to that in this video, I was able to get it pretty quickly.

      Steve Garcia
      Central Mexico

      1. Nice sleuthing! That definitely is the location, and most calculated paths I’ve seen pass exactly overhead of this location.

    1. I’ve found some problems with this video taken from Otradny (not “Otradnoye”) near Samara. Notice that fireball is well above the horizon. Earth approx. diameter is 12740 km, distance from Korkino to Otradny is near 680 km. Simple calculation (or plotting) demonstrates that you can observe objects at altitudes no less than about 35 km at such distances! I suggested that this mismatch may be due to some atmosphere optical effects (that also can not be excluded and may be important for large-distance obsrvations).

  15. For Sean Mac
    You said that on a Chelyabinsk traffic camera a car alarm started 160 seconds after the meteor.
    If this is the video
    http://www.youtube.com/watch?v=tWYGbOQubIk
    I see it start at about 142 seconds.
    And a person standing near the car seems to react to something.
    Can you tell me the camera location please.

    1. The location is written in the bottom left corner. It’s a public webcam at 55.143883, 61.41443. You can also watch the camera on Google’s maps webcams layer.

  16. Yet another idea, may be interesting: if operator started recording after the meteor passed the sky (the most common situation), it may be possible to estimate time (more or less precise) by comparing some small details of the contrail using videos with fireball taken from the similar perspective. A good 4D model (3D+time) of developing contrail is desirable for such purposes (but not strongly required at first steps). A huge work, BTW…

  17. Serge, can you be more specific about your claim, that the corner of the building seems to be misplaced?
    The frontal building from the video is under construction on Google satellite map. Only the basement is visible. And the corner stays left if you look at the camera towards the landing site of the meteor.

    1. Posting on Serge’s behalf:

      =======
      Yandex maps has fresher satellite images in this region and they also crowd-source vector maps. Here is the map http://maps.yandex.ru/-/CVRP4B0b and here is the image http://maps.yandex.ru/-/CVRP4B96. I believe the white building on the video is 18k2. What you think is a building under construction is probably a demolished building. Here is also a map with height perspective http://kvels74.ru/uploads/company/70854787/map.png
      =======

  18. For ssvilponis
    On your very nice path map
    http://goo.gl/yd7Jk
    You show a meteorite find reported near Kuvashi which is about 60km down range from Lake Chebarkul.
    I see no evidence in the videos for this.
    A dark filght of about 75km does not compute.
    I would be very interested to find out if it is a real meteorite, and similar to the Lake Chebarkul meteorites.
    And if so, if it was transported by someone to Kuvashi.

    1. To: Steve on February 22, 2013 at 04:36

      Some pieces of the cosmic body fell down earlier, mostly starting with the “explosion” – fast disintegration of the meteor. Those pieces were too small to leave a visible contrail and fall down earlied because of sudden loss of velocity in violent disintegration process.

  19. Great site, some excellent analysis. But I see a few big problems with some of the analysis, mostly related to descent angle, and attributing too much significance to the plane defined by the meteor path and an arbitrary observer’s location. #1: With such a linear path, 1000 different observer locations give 1000 different planes, 1000 different plane intersections with Earth’s surface, etc. #2: So, except for observers seeing it pass through their zenith, the plane intersection with Earth is not the ground track. #3: Drawing any/all of the proposed paths to the ground at Chebarkul Lake is definitely an error, as it gives each of thee proposed paths a different heading for its ground track, all radiating out from the lake. #4: Having solved the ground track heading as being 282.5 degrees (good work!), just draw various proposed paths on your plane, all having ground track heading 282.5 with the ground track passing over the lake at various altitudes. #5: In general, when measuring every photo or video with a protractor to see descent angle, remember that the measured angle is simply an upper limit on how steep it might be. Even the trail of an airplane in level flight can be made to appear perpendicular to the horizon (by an observer whose zenith it passed through), but a vertical pole can never be made to appear parallel to the horizon. Every photo makes the path look steeper than it is, except for an observer perfectly positioned to show the true angle (by sheer coincidence, in a case like this where they didn’t “know” where to be for a protractor-ready view). #6: There is some info about a fall area 80km farther along the path than the lake. I have seen it variously described as Zlatoust area or village of Kuvashi. Without knowing the impact velocity there, it is impossible to say where a straight-line impact would have been, which the path must be aimed at.

    1. Re #2, I don’t think anyone assumed that. The reason the contrail on the meteosat 9 image fits the ground track of the plane as seen from central Chelyabinsk in the video is because the satellite, completely by accident, also found itself aligned with that plane.

  20. My last comment was not suggesting that we can calculate where near Kuvashi it must be. I was suggesting that Kuvashi is too near to be the “linear aim point”, as would be any other found meteorite from this event.

  21. For ssvilponis
    in this video

    you can see the formation of the explosion trail at 09:20:31
    If you carefully watch the right end of the explosion trail, in the next 4 seconds it moves to the right.
    So videos taken of the explosion trail cloud more than 4 seconds after it was formed will show it displaced down range.

    Re my earlier message about a meteorite reported near Kuvashi.
    When people see a meteor go below their horizon or behind objects near the horizon they frequently think a meteorite landed nearby not realising how far away the meteor really was.

    1. To: Steve on February 22, 2013 at 05:25
      Forming of the contrail is complex process and during the fall there are some differences there, as atmosphere is layered (different density, temperature, moisture content etc), the disintegration speed varies and energy involved decreases. For finding azimuths I used contrail ends after they were (almost) completely formed. Some times it was little tricky as video was filmed from a moving car.

  22. For ssvilponis
    I think the most important thing now is to estimate the height of the vanishing point above ground.
    Was it 25km, 20km, or 15km, this affects how far the landing zone might extend beyond Lake Chebarkul.
    It will also give a more accurate radiant for the meteor.
    In my option the landing zone does not extend very far beyond Lake Chebarkul, if at all.
    We know the explosion trail height and location, so for each video its elevation can be calculated.
    To allow for the curvature of the earth subtract
    H = D²/12.75
    from the height
    where H is in metres, and D is in km
    This should only be a small correction.
    This can then be used to estimate the elevation of the vanshing point on the video, we already know the distance so the height can be calculated.
    You will need to add the above correction for the vanshing point height.

    1. Steve on February 22, 2013 at 06:44 said:

      I think it should be relatively easy to find the height if to use two near but opposite views (with some decent orients) to the vanishing point. But this is not my priority now. Instead I try to find more information for my sound delay map. It should give some idea about altitudes. At first I assume that the speed of the sound is constant, 300 m/s. Afterwards, as I know the approximate height, I can use more complex modelling.

      1. You can try my excel worksheet:

        https://docs.google.com/file/d/0BwwWPUHhxn2ESERRYXRsTUlWdk0/edit?usp=sharing

        Calculations based on the 3-layer atmosphere model (temperature falls from the ground-T to -56.6°C at 11 km, then T=const up to 25 km, then rises again). It is very simple but widely used approximation if actual T-Alt is not available. I’m also interested in such calculations, I think it’s possible to detect hypersonic shock waves by such way if their speed was high for some distances…

        I found also another model with more layers, but I did’n use it yet.

        BTW, I have found several papers about meteoritic acoustic waves, 2 of them may be interesting to read:

        J.B.Tatum, L.C.Parker, L.L.Stumpf (2000) Sound from a fi reball – distinguishing between the hypersonic shock front and the terminal burst. Planetary and Space Science, v.48, p. 921-923

        J.B. Tatum (1999) Fireballs: Interpretation of airblast data. Mefeorrfrcs & Planefury Science, v.34, p. 511-585

        The latter contains chapter about supersonic shock fronts, too (and provides some estimations…)

  23. Greate job!

    I’ve made an estimation based on the luminous part trajectory taken from outskirts Chelyabinsk, Kamensk-Uralsky and Magnitogorsk. The flight path is parallel to your updated estimation. Your initial trajectory contradicts Magnitogorsk footage. (road is parallel to estimated trajectory while on the record it is not).
    Soon I’ll be able to publish calculations for comparisson.

    Best regards,
    Vladimir.

  24. Congratulations, amazing job!
    You are even more crazy than me: I only THOUGHT about doing this job…. but I eventually didn’t even try it due to complexity of calculations…
    Anyway, I have some more data for you to play with:
    a shot taken just from above the scene from a military satellite:

    An image to be verified against GoogleEarth to figure out if it’s fake or real. I’m trying doing this, but maybe you’ll be faster than me.

  25. For those of you still following along, I’ve just added an update to the original post:
    ====
    UPDATE 2013-02-22: OK, so this is kind of special: An astrophysics paper has just been submitted to ArXiv.org that models the orbit of the Chelyabinsk meteor, referencing this blog post as a starting point: A preliminary reconstruction of the orbit of the Chelyabinsk Meteoroid by Jorge I. Zuluagaa and Ignacio Ferrin. Details are here, and here comes the resulting animation:
    ====
    Check the post for the Youtube video they made.

  26. Congratulations Stefan The astrophysics paper makes the
    same simple assumption as you, that an extension of the descending
    straight line path of the meteor intersects the earth at Lake
    Chebarkul. It does not, it passes high above Lake Chebarkul. This
    occurs because as the speed reduces gravity has more time to
    deflect the path into a much steeper angle. The simple assumption
    results in an arrival angle that it to steep.

    1. Some physics to take into account for a more accurate
      model: – an object in horizontal movement at constant speed over a
      flat surface starts falling along a parabolic path as soon as the
      flat surface “ends”: horizontal speed remains constant (neglecting
      air friction), but vertical speed starts accelerating like “9,81 *
      time”. Same happens if initial movement is not horizontal but
      obliquous, but modelling it is quite more complex. – taking into
      account air friction, horizontal speed is not constant also; air
      friction affects speed by mean of friction force: F = 0,5 * ro *
      CdA * speed^2 ro = air density CdA = Total drag coefficient, made
      of Cd*A, where Cd=”empirical drag coefficient” and A = frontal area
      (=section). This makes all very complex as you can’t exactly know
      bot Cx and A, and ro varies with altitude! It’s quite a mess! :-)
      Only thing you can say by sure is that if meteorite entered
      atmosphere in point A with direction (D), the line crossing A
      toward (D) CANNOT pass through the impact point L (lake), which
      MUST be closer to A due to air friction. Hence, if actually
      meteorite was found in the lake, the initial trajectory angle w.r.t
      horizontal line must be SMALLER than the angle between AL line and
      the horizon. Drawing: http://penolo.com/rrUX

  27. For ssvilponis On your map you have the Kartaly video
    placed next to Yuzhnouralsk. The Shelomentsevo video does not load
    for me with my viewer.

  28. Here is a meteoric event similar to the Chelyabinsk event.
    1919 Nov 27 ~02h UT Michigan/Indiana USA ~42ºN ~86ºW The Washington
    Times (D.C.) 1919 Nov 27 page 1b.
    http://chroniclingamerica.loc.gov/lccn/sn84026749/1919-11-27/ed-1/seq-1/
    “EARTH QUIVERS AS SKY PHENOMENON DESCENDS Electric Plants Wrecked
    As Strange Visitor Appears on Michigan-Indiana Line. CHICAGO, Nov.
    27. – Telegraph and telephone communications and electric lighting
    plants in several cities in southern Michigan and northern Indiana
    are out of commission today as a result of a remarkable phenomenon,
    believed by several scientists to have been a gigantic meteor which
    rushing earthward from the East appeared to dissolve as it
    approached the earth near Athens, Mich., last night. The phenomenon
    is reported to have assumed various forms, in its race earthward,
    ranging from a brilliant illumination to a heavy rain accompanied
    by heavy thunder. The phenomenon was seen over Chicago by several
    persons. It was reported here shortly before 8 o’clock. It appeared
    over the lake and resembled in appearance an extraordinarily
    prolonged flash of heat lightning. Athens, Battle Creek, and Three
    Oaks, Mich., report considerable damages to property. At Athens, it
    is said, there was an earthquake, continuing for fully three
    minutes, accompanied by a heavy rain and wind storm, a loud clap of
    thunder, and a flash of light in the sky of longer duration than
    lightning. At La Porte, South Bend, Fort Wayne, Warsaw, and other
    Indiana points, windows were broken by the concussion. The Calumet
    Electric Light Company, at Kalamazoo, Mich., and several smaller
    plants throughout this section of the country were temporarily
    disabled.” Area of reported building damage and smashed windows:-
    Athens Michigan 42.09ºN 85.23ºW Battle Creek Michigan 42.31ºN
    85.20ºW Three Oaks Michigan 41.80ºN 86.62ºW La Porte Indiana
    41.61ºN 86.72ºW South Bend Indiana 41.67ºN 86.26ºW Fort Wayne
    Indiana 41.08ºN 85.14ºW Warsaw Indiana 41.24ºN 85.85ºW The main
    difference is that the impacted area of Michigan/Indiana had a
    small number of people and buildings compared to the Chelyabinsk
    area. This event made front page news and was investigated at the
    time by astronomers, but has been completely forgotten. You will
    not find it on any list. How many more events like these have been
    recorded and forgotten.

  29. For ssvilponis No meteorite at Kuvashi. Update. February
    16, 2013 “searches were conducted at the village Zvyagino and
    Kuvashi. According to the assessment by the Commission of the
    Government of the Chelyabinsk region, finds of the celestial body
    remains failed.”
    http://meteorites.ru/menu/press-e/yuzhnouralsky2013-e.php
    Approximate place of falling Chelyabinsk’s meteorite near the
    Kuvashi village. Coordinates: 55°8’43″N 59°26’54″E “This place was
    deleted, it will be removed from all search engines in few weeks.”
    http://wikimapia.org/26842025/deleted

  30. For ssvilponis sound map:
    http://krasview.ru/video/342138-METEORIT_15_02_2013g_Chelyabinsk_Chel.obl._g.Emanjelinsk.
    The only video I could find south of the trajectory. It started at
    54.75587, 61.30517 and unfortunately it was cut in the middle while
    the car was moving. I think at the end the car was parked facing NW
    at one of the building not that far away, for example at 54.759006,
    61.30369 or 54.762482, 61.309376. Even though the exact location is
    not known as far as I see it does not confirm to the current
    trajectory on your sound map. Did I miscalculate
    something?

    1. Max. flash is at ~09:06:22, thunder is at 09:07:53, delay
      is 91 sec (observ. angle may be near 80°), and 88 s on well-known
      video from the market-place in Korkino (angle was near 68°). I
      don’t see dramatic differences (taking into account that some
      assumptions may be wrong or too simplified, e.g. regarding first
      thunder source points and cyllindrical shape of wave front). More
      thorough analysis is required to fine-tune distances and altitudes,
      I think.

      1. Intersection of wave front with the ground surface should
        be elliptical if trajectory is not parallel to the
        ground…

      2. Misprint is in my previous post: angles should be 80° for
        the Korkino video and 68° for Yemanzhelinsk…

      3. I was confused by the lines on ssvilponis’ sound map
        http://goo.gl/pNxPh After I found Pervomaysky video, I see the
        Yemanzelinks dashcam video is fine. The explosion was above
        Pervomaysky. BTW I assumed the flash on the video is at 6:23,
        windows destroyed at 7:22.5, delay is 89.5. Also while you say the
        Korkino delay is 88 while ssvilponis maps says 89. Hopefully
        whoever does the final calculations will rectify the
        discrepancies.

    2. Serge, you can use this video from Troitsk, too:
      http://youtu.be/6TYV4EQvz2w Observation angle is measurable by
      object/shadow proportion, delay is about 5 minutes(!), detected by
      the first cam vibrations. Coordinates: 54°2’26.72″N,
      61°38’59.18″E.

    3. To: Serge on February 23, 2013 at 08:12
      Thanks! Found the exact place and included it onto map.
      Do not pay too much attention for distance and altitude calculations as I am still looking for more source data and preliminary calculations are very much simplified.

  31. I just pinpointed the location of a video from Pervomaysky
    http://www.youtube.com/watch?v=R99zvcrqXo8 – 54.872644, 61.200792.
    Watch the video, it looks like they are located right below the
    mushroom formation. If a panorama picture can be created from the
    video, it will be easier to see. Also if you measure the distance
    from the Korkino dashcam and the Yemananzelinsk dashcam I just
    posted they are almost at the same distance from that point, so it
    looks like that’s the location of the explosion.

  32. Don’t forget the upper atmosphere winds. The small
    meteorites that landed at Deputatskoye seem to have been blown
    south by a wind during their long fall. A south wind would mean
    that sound would arrive in less time at Yemanzhelinsk than if there
    was no wind. Can anyone find data on the upper atmosphere winds
    around the time of the meteor.

  33. Hi Stephan, This is so great to see. It’s riveting looking
    at your work and the collaboration from commentors. I have a small
    contribution to make below but can I first ask a question in
    relation to it: Have you got an Azimuth for the trajectory? Or
    maybe just the angle from true North of the ground track? I tried
    to use google Earth to click on the end points and work out the
    angle but I’m on an iPhone app- it won’t work. I can judge it as
    maybe 105 degrees but it would be nice to get it exact. My
    contribution is this: Firstly, I think the reason the the satellite
    image trajectory looks very convincing is because of parallax. From
    geostationary orbit, the Earth’s surface is slanted away at 55 deg
    at that point. Then you have to add another 7 deg for the
    translational displacement of the satellite about 5000km down in
    the equatorial plane. That’s 62 degrees. This means what we are
    really seeing is the plume projected onto to the surface in the
    wrong place. This effect gets worse the higher up the plume you go
    so at the 30km high point of the explosion it is projecting that
    56km north of the true ground track point (the complement angle of
    62 deg is 28 deg so the horizontal northward projection is the
    reciprocal of tan 28deg x 30km). The good thing is that if that’s
    the case it fits perfectly with your ground track at least when you
    eyeball it and assuming the inclination angle is correct which it
    seems to be. The second thing is that I don’t think Phil Plait’s
    vid is Meteosat 9. The other horizon photo is because its the right
    angle. Meteosat 9 is over the Greenwich meridian hence the eastward
    angle foreshortening. I think the video must be another
    geostationary satellite. Its much less foreshortened, if at all.
    There’s one over India. It doesn’t affect my point above- in fact
    the more square on in terms of longitude the geostationary
    satellite is, the better the latitudinal parallax can be resolved.
    Thanks, I hope that helps and if you or a commenter can help me
    with the azimuth/ bearing from north question about the tranectory,
    I’d be really grateful.

  34. There is a little viewed (603 views) video from directly (I
    guess within 1km or so) underneath the meteor’s trail, about in the
    middle of the most explosive part of its travel:
    http://www.youtube.com/watch?v=R99zvcrqXo8 I got these coordinates
    via an email update for this page written by Serge (who mentioned
    Pervomaysky), but the text of that update does not appear on this
    page itself. This video was clearly taken at the coordinates Serge
    supplied: 54.872644 N, 61.200792 E, with three smokestacks behind a
    building:
    http://maps.google.com/maps?q=54.872644+N,+61.200792+E&hl=en&ll=54.872687,61.202066&spn=0.004574,0.008497&sll=51.533333,55.008889&sspn=0.660343,0.582275&t=h&z=17
    This is the Korkino Cement Plant:
    http://www.lafarge.ru/wps/portal/ru/en/2_1_A_2-UralCementPlant next
    to the Klubnika railway station which is about 1.5km ENE of
    Pervomayskiy (note the ‘i’) AKA Pervomaiskii. This about 8km WSW of
    Korkino. I think this video locates the meteor’s path with a
    north-to-south accuracy better than any other evidence I recall
    seeing. Also, it may be possible to locate the features of the
    smoke trail in the east-west direction from this video. Serge made
    several contributions to this page, including the coordinates of
    the Korkino marketplace video, but all that appears is his first
    name.

  35. Hi Stefan, Here is a video:
    http://krasview.ru/video/342138-METEORIT_15_02_2013g_Chelyabinsk_Chel.obl._g.Emanjelinsk.
    with the final part of entry clearly visible, and then with
    multiple windows in a 5 storey building being blown in. This is
    taken with the same dashboard camera. The 90 time delay can be
    measured accurately from the meteor being at maximum brightness
    roughly overhead. This was a little south of the path. The
    translation of the title and Google maps enabled me to find the
    exact location. Just at or after the peak brightness, the car
    travels NW under a pipeline, which is visible with its shadow,
    directly SW of the L shaped building at 54.75639 N, 61.304564 E.
    https://maps.google.com/maps?q=%D0%95%D0%BC%D0%B0%D0%BD%D0%B6%D0%B5%D0%BB%D0%B8%D0%BD%D1%81%D0%BA&hl=en&ie=UTF8&ll=54.75639,61.304564&spn=0.002393,0.004249&sll=-37.73563,145.07369&sspn=0.05247,0.036392&t=h&hnear=Yemanzhelinsk,+Yemanzhelinsky+District,+Chelyabinsk+Oblast,+Russia&z=18
    The overhead brightest part is around 6:23. The shockwave arrives
    at 7:53. Someone with better knowledge of sound propagation, given
    the very high intensity of the shockwave near the meteor, could
    probably come up with a good estimate of distance within 1 km.
    There is information on the speed of sound here:
    http://www.sengpielaudio.com/SpeedOfSoundPressure.pdf but the
    pressure of this wave is extremely positive, so it may travel
    faster than the usual measures of low intensity sound, such as:
    http://en.wikipedia.org/wiki/Speed_of_sound A guess is 310m/sec *
    90 = 27.9km, with the meteor path being very close to vertical
    above this location, tilting somewhat downwards to the west. If we
    could find other similar time-delay videos along the path it may be
    possible to reasonably accurately deduce the angle of the path,
    even without making exact assumptions about the velocity of sound.
    As you pointed out, so far the best estimate of the path and what
    kind of asteroid orbit it may have come from is the work by Jorge
    I. Zuluaga & Ignacio Ferrin: http://arxiv.org/abs/1302.5377
    – based on your work on this page.

  36. For ssvilponis
    The Deputatskoye and Bereznyaki meteorites look real to me (amateur astronomer).
    It is very reasonable they are small pieces from the explosion south of Korkino blown south of the meteor path by winds.
    I think your landing zone should include them.
    Also, clearly from the videos, pieces landed all along the path before the vanishing point.

    I don’t know if there were meteorites found at Pustozerova, it is quite possible.

    I think the landing zone should extend from a little past Korkino to a little past Lake Chebarkul.

    1. Steve, it is possible, that small pieces reached the ground
      all the way since meteor descended into higher density atmosphere
      layers. I extended the area towards Zlatoust when there was a rumor
      about meteorite found near Zlatoust. I provided the area as my
      rough prediction only. Now I can’t see any other reason to still
      keep this area on the map, than one Norwegian newspaper published
      this map on their online edition and they referenced the magenta
      area in the text beneath the map. Known meteorite sites are now
      more precise information for searching teams, than my
      prediction.

      1. Thanks, Venus Explorer! I think the plane is not able to travel so fast, but thanks to you I recognised the terrain. The Bombardier CRJ-200 should travel at 700…800 km/h so during the gap between those two pictures (23s) it could travel only 4500…5000m.

        1. I think that is not The Bombardier CRJ-200. I think this is
          another plane to fly to another city by the way near Chelyabinsk.
          Unfortunately I do not have any additional information about these
          photoes.

          1. I agree! It might be, that those photos came from another
            airplane. Time and position of these photos has discrepancy with
            some details of the copilot report. I included the plane to the map
            to remind me to do some research about air traffic. I think it
            might give some information about the slope of the meteors
            trajectory.

  37. For ssvilponis: Very good location for triangulation:
    http://www.youtube.com/watch?v=mpKBXsowQfE It’s hard to see so feel
    free to double check the exact location. I believe the video starts
    at 55.00715, 61.19830, the car passes the beginning of the divider
    at 0:21 located at 55.007828, 61.20818, parks 55.008247, 61.21551
    and the explosion sound reaches the car at 55.00829,
    61.21638.

  38. http://www.youtube.com/watch?v=Y_u-MNyBnDk#!

    The moment of the worst building destruction (Zinc Works) caught on a dashcam video, a second earlier than the sound reached the car. That should silence any speculation that it was hit by a piece of meteorite.

    There is also the flash on the same camera http://www.youtube.com/watch?v=IWoe4Tqeu3o but I think we have enough sound delay videos from Checlyabinks. I’m not sure we need more of them from the same direction.

    1. I think the zinc plant zone should still be included as
      there were major damages to the buildings. Unfortunately I cant
      read the time stamp of the video (video is stabilised afterwards?)
      and because the video is cut into separate scenes, I cant rely on
      player time either.

    2. On some video near Zinc Works, could see the road sign
      “methane”. My hypothesis the wall destruction could connect with
      artificial detonation by sonic wave. But this is only
      hypothesis.

  39. I’ve added some features to Stefan’s KMZ file that include the cement factory data and a satellite photo I found at the Baltimore Sun. The KMZ file is available at http://greenes.com/index.html .

    Я добавил некоторые возможности для KMZ файл Стефана, которые включают цементный завод данными и спутниковые фотографии я нашел в Baltimore Sun.KMZ файл находится по адресу http://greenes.com/index.html.

  40. On your path map
    http://goo.gl/yd7Jk
    Just after you added the “Railway pole, Kartaly” symbol and the angles from Kartaly to the meteor, I noticed there was no “Spot of taking a video” symbol for the Kartaly video location.
    video
    http://www.youtube.com/watch?v=vl_kD8WtQyY#
    I still do not see it.

    I then went and clicked on the “Spot of taking a video” symbol at Yuzhnouralsk. To my surprise it said Kartaly.
    It now says Yuzhnouralsk.

    Symbol “Nadir, Shelomentsevo”
    http://tati.kiev.ua/video/14028/
    When I try to look at this video, my Adobe Flash Player 11 says “Movie not loaded”.
    I have not seen MeTube before, does it require a different viewer?

    Minor data entry errors on your sound delay map
    http://goo.gl/pNxPh
    Korkino
    D=300*89=2697m by sight [2697 => 26700]
    89s 26700m by sight 48700m by ground A=26252m [48700 => 4870]

    Lesoparkovaya
    D=300*140=4200m by sight [4200 => 42000]

    1. Steve, I think you just saw a moment of editing. Sometimes
      I had to displace a object to get access to another map element for
      correction. For Shelomentsevo video I do not use any special
      player. It just plays in browser like the other videos. I think
      that the problem is not related to the MeTube, but the camera
      codec. Thanks for pointing to errors!

  41. The most western video: http://www.youtube.com/watch?v=mJ7SL9PDsu4 Note the largest piece still didn’t hit the earth 80km after passing Cherbakul lake! The uploader provided the location, village Teploe near Satka city. The village is pretty small with the center at 55.04972, 58.93938, but I think the video was shot from one of the corner houses at 55.05159, 58.94324.

      1. From Serge:

        To jumpjack: I guess you have to be a native Russian speaker, Google
        translate does not work. You have to know abbreviations used in
        addresses. This is the comment by the uploader: “Челябинская область,
        г.Сатка, в трех километрах от центра города (пос. Теплый)”.
        Translation: “Chelyabinks region, Satka city, 3km from the center of
        the city (settlement Teply)”. I accidentally changed the ending of
        Teply in my previous post because I translated пос. (поселок) as
        village. Now I think settlement is a better translation. Another
        problem is that some Russian letters can be transliterated in
        different ways and that may prevent search from working. Teply can be
        written as Teplyi, Tepliy, Teplyy or Teplyiy.

        After getting the location name I used wikimapia.org to find it
        visually near Satka city. I have also confirmed the location by going
        to maps.yandex.ru and right clicked on it to use “Что здесь?” (“What’s
        here?”) feature.

        In general in Russia wikimapia.org and n.maps.yandex.ru (note the n.
        in the beginning, it’s crowdsourced maps supported by yandex) have the
        most features mapped. maps.yandex.ru is the best verified map.
        maps.google.com has the highest resolution satellite images.
        maps.yandex.ru has the most recent satellite images.
        ———————

    1. Sorry, but the video does not show the shock wave. It would
      be interesting, what was the delay in Miass. If it reached there at
      all.

      1. I am fairly sure that video was previously a lot longer,
        and showed movement several minutes after the flash.

  42. Here’s some info on the position of the sun at 03:20 UTC
    (GMT) on 15th Feb 2013 at the locations of Korkino and Cherbarkyl.
    I’m including it because the suns position is uncannily
    coincidential with the meteor trail and quite useful for
    calculations. Korkino coordinates are from the Wiki entry but to
    two decimal places (about 1 mile). Cherbarkyl coords are from this
    blog thread. There’s not much difference between the sun position
    of course but I included both for accuracy. Korkino: 54.89N 61.38E
    (decimal lat and long to 2 dec places) Altitude: (minus) -0.42
    degrees (+0.26 deg with refraction) Azimuth: 111.74 degrees
    Cherbarkyl: 54 deg 59N 60 deg 22″ E (not decimal) Alt: (minus)
    -0.98 deg (-0.16 with refraction) Azimuth: 110.92 degrees Altitude
    is height above horizon. Azimuth is angle from north through East
    so these azimuths show the sun is about 11-12 deg south of east. We
    know from Stefan’s map that the meteor path is around 110 deg
    azimuth. This means that the rising sun was almost directly below
    the meteor radiant (or the plume as you looked back along it).
    However, because the video above (with the plume almost head on
    with the suns ray-shadow) shows the sun as south of the plume (ie
    to the right of being centred below), it means the plume line can
    be constrained to less than 111.74 degrees of Azimuth for sure (the
    point below the explosion plume). Also the fact that sun was on the
    horizon was probably the reason for such a great ray shadow. And
    incidentally, it wasn’t on the horizon for the plume 30km up. At
    Cherbarkl, the -0.16 azimuth (for centre of suns disc) means that
    the top tip of the suns disc was at the horizon (in theory, 2% of
    the disc above! according to figures above- but a change of a few
    miles or minutes would change that). Where the video was taken it
    must’ve been just breaking the horizon but for the plume it was
    fully risen. A word of caution: that ray shadow looks like its at a
    big angle to the plume but it can’t be. It’s foreshortened by 80km
    or so therefore it fans right out like suns rays through clouds
    over the sea. But I suppose it could be calculated using the
    coordinates we have, eyeballing the angle in the video and flipping
    it over geometrically so we are looking down flat from above. I
    guess it must be at least 2 or 3 degrees which would corroborate
    the 110 or thereabouts line you have already. But it might just
    push it back to a tad less than 110 perhaps? If you could find
    another ray shadow plume video it might be usefu too. Coordinates
    above for the sun were used by converting the sun’s equatorial
    coordinate position from the JPL Horizons ephemeris tool at 03.20
    GMT on the day. Therefore it was a conversion from celestial
    coordinates to local horizontal coordinates. Hope that’s of help to
    someone. Scute

  43. Our parameters of the trajectory are (Spurny et al.):
    Relative Longitude Latitude Height Velocity Notes Time (s) (deg E)
    (deg N) (km) (km/s) 0.00 64.266 54.508 91.83 17.5 beginning of
    registration 9.18 61.913 54.788 41.02 17.5 minor flare 11.20 61.455
    54.836 31.73 17.5 major flare 12.36 61.159 54.867 25.81 17.5 flare
    13.20 60.920 54.891 21.05 12.5 minor flare 16.20 60.606 54.922
    14.94 4.3 end of registration Pavel Kalenda
    http://www.youtube.com/user/firstyurka

  44. Correction! In my last comment I meant Stefan’s
    reconstruction was around 100deg azimuth, not 110. But the video
    can still be used as I suggested to corroborate the findings along
    with the sun’s azimuth. It’s like the last word, to prove you are
    right. Sometimes people look at the hard-won research evidence and
    don’t ‘see’ it and have their doubts. The sun’s angle says it all,
    just to convince them.

  45. JPL’s HORIZONS system uses a “standard atmosphere
    refraction model”. You cannot enter the actual temperature near
    ground level at the time of the meteor, which was around -10ºC. The
    International Standard Atmosphere Base Temperature is +15ºC. Under
    average conditions a base temperature of -10ºC would mean slightly
    more refraction compared with +15ºC. However the actual refraction
    at the time depends on the rate of change of temperature with
    altitude. Changes from average conditions can vary refraction at
    the horizon by 0.3º or more.

    1. If you use the “reply” button on a post, your reply will
      appear immediately after that post. If you use the reply box at the
      bottom of the page, you start a new series of replies, not attached
      to previous comments and that makes the conversation impossible to
      follow

    2. Not really. But human mind can be easily fooled.
      Perspective together with the lens distortion may create such
      illusion, especially when landscape is not flat. In case of
      favourable wheather you can observe how lonely cloud casts shadows
      at sunset or sunrise. But if you like to think, that this is not a
      shadow, then you can think what you like.

  46. Comments on the provisional trajectory calculated by
    meteoric scientists.
    http://www.webalice.it/mizar02/articoli/Meteorb.dat They modeled
    the visible trajectory as a straight line, which is a good
    approximation. The ground track of this trajectory is a great
    circle. This great circle equation matches the tabled locations
    within ±37 metres. Latitude =
    arctan(1.453875*sin(41.029+Longitude)) Enter the Longitude in
    degrees and it gives the Latitude where the ground track crosses
    that Longitude. Their ground track passes very close to the Yetkul
    (Etkul) camera site, but it crosses Lake Chebarkul 2.2km south of
    the ice hole. They seem to have used an average of the trajectories
    of the largest fragment and smaller fragments. The ground intercept
    point of the trajectory is ~54.995ºN, ~59.818ºE with arrival
    azimuth ~98.9º and elevation ~16.09º. This location is about 33 km
    beyond Lake Chebarkul. As you travel back along the trajectory the
    azimuth and elevation both increase. This is because they are
    defined by a local coordinate system. At the start of the visible
    trajectory the inclination is over 17º.

  47. I don’t see it reaching Earth’s surface. But I also have
    difficulty fully understanding what I see. The shadow does not seem
    to start at the lit contrail cloud as it should. In fact, an unlit
    piece of contrail seems to be blocking the view of the lit contrail
    cloud. Or more likely, it is not directly sunlit, but only backlit
    by the lit cloud. Yet the dark streak by the time it is near the
    camera and heading to the left horizon, is definitely a shadow. It
    even seems to be diminishing toward the left as it should. Because
    the sun is not a point source, but about a 1/2 degree (1/115
    radian) disc, the visible (umbral) shadow it casts is a cone ending
    at a distance 115x the size of the object casting the shadow. If
    the contrail cloud is a 1km sphere or cylinder, its shadow cone
    ends 115km away (at the most). The larger penumbral shadow is
    difficult or impossible to notice.

    1. If you use the reply box at the bottom of the page, you post a disconnected comment.

      Please use the reply button on the post you want to reply to. This whole thread is now a maze of disconnected comments that are almost impossible to follow.

      SITE OWNER: Is there any way to re-thread the comments so that this lot is readable?

      1. I’ve been traveling in Africa pretty much since I posted the original article so: no, I don’t have much opportunity right now to fix anything, mainly just modding comments.

      2. It’s not my fault, this blog platform is ugly and makes my tablet go crazy…
        I click on REPLY in notificarion email, I’m brought to a page like https://ogleearth.com[…]//?replytocom=7876#respond , then a youtube clip starts (???) and the textbox at the end of the post appears…
        This reply should then associate to comment 7876, let’s see what happens! I’m now trying from PC, but anyway I’ve been brought to post-end-text-box.

        1. Other WordPress blogs have the main reply box at the top so
          you see it as you scroll down. Can this one change its box to the
          top? WordPress is a clumsy old platform anyway- there are loads of
          ways to improve it.

  48. AS have many, I found your Chelyabinsk meteoroid analysis and blog immensely entertaining; however an issue that I haven’t seen addressed (though touched on briefly in your blog comments by wzrd1 on February 16, 2013 at 03:44 :
    “A few minute either way, earlier or later in our mutual orbits, it’d have been a fireball that went back into space again or a city crushing repeat of the Tunguska event- over a populate area” is calculation of the locus of quasi-equiprobable future impact sites, given the vast number of Apollo group objects in closely similar orbits.

    Naively, I would think (?) that the earth’s spin on its rotational axis (365 times quicker than the annual orbit shown by Zuluaga and Ferrin in their wonderful Apollo group earth-crossing orbit animation would mean that the a priori “most likely” future impact sites lie in an annular, circumferential ring centered on 55°N latitude (Chelyabinsk)

    However, if, say, it’s known by astronomers that Apollo group orbits are widely dispersed “laterally”, possibly of much greater breadth than the earth’s diameter, and/or that relative orbit inclinations are such as to bring Apollo group objects “below” as much as “above” earth at their points of intersection– then, I guess, that would greatly broaden north/south projection of the expected impact hazard zone. At any rate, that’s the question I and other northern hemisphere home owners would like to see addressed.

    Thanks
    ————-

  49. So the asteroid detonated roughly at the same altitude as Austrian Felix Baumgartner record balloon jump….cool.

  50. Steve Garcia
    Good work in finding the location.
    Wikimapia says this is Pumping station “Etkul”.
    The pole you give is not the pole with the camera.
    If you look at Wikimapia there is a small building beyond the 2 pipelines.
    At one point on the video the meteor lights up the east face of this building making it easy to see.
    If you draw a line on Wikimapia from the north corner of this building to your camera location the line just touches the south-west corner of the tank.
    In the video however, there is a large angluar distance between the north corner of the building and the south-west corner of the tank.
    The camera location must be much closer to the tank.

    It is not easy to see, but I believe there is a tall tower in the distance seen above the tank that appears higher than the distant trees.
    Best seen on the google earth image of June 2009.
    54.849332
    61.549534

  51. What would be interesting would be a careful search of Chebarkul for any high resolution security camera video that might show a small dark object, the meteorite, fall from the sky.

  52. Wait what if we want to believe the sound of the sonic boom traveling to be unrelated to the meteor. Say a hoax, How do you prove the height of the contrail over Korkino. I have seen some videos that show the contrail SO close to the Camera.

    I cannot believe that it is in the mesosphere. As the Mesosphere starts at 30 miles from the surface.

  53. I believe that this meteor was a moonlet of 2012 DA. True, they followed different trajectories and when they passed, the meteorite was way too far from 2012 DA to be a moonlet. But consider that the earth’s gravitational force might have pulled the meteor away from the 2012 DA and out of its orbit. Not inconceivable.

    1. Only if we redefine the law of gravitation, orbital dynamics and make small objects be attracted more than large objects, which would also redefine kinematics.
      Totally inconceivable. Especially considering using those known laws, everybody and their brother have put satellites and landers on the moon, as well as a few satellites and probes to mars and outer planets.

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