October 10, 2019 16:16 UTC – U.S. Government Sensors detected a 0.57 kiloton event in China’s autonomous region of Inner Mongolia, near the town of Tiebeicun. Originally, it was thought that the The geographic area where meteorites landed, from a specific meteor event. The strewn field size and shape are affected by the size of the event, the slope of the meteor, and the wind speed and direction. Generally speaking, meteors that come in a steep angle will generate smaller strewn fields than those that come in at a shallow angle. The presence of wind will affect the size and shape of the strewn field by scattering... was in Inner Mongolia, but it turns out, it is likely over the border of the Jilin province, near the city of Songyuan.
This meteor event has been updated. For the originial posting, please visit Inner Mongolia!
|Date/Time:||10/10/2019 16:16 UTC|
|Location:||Songyuan, Jilin, China|
|Reference Coordinates:||45.071177°E 124.47472°N Google Map|
|Reference Altitude:||14.716 km above sea level|
|Energy / Mass Estimate:||0.57kt / 24111kg|
|Entry Speed:||14.1 km/s|
|The direction of travel of the meteoroid, relative to the ground, in clockwise degrees from North. The terms "heading" and "bearing" may be used interchangeably for projectile motion....:||72.3° NE|
|Incidence:||40° from vertical|
Jilin Province, Not Inner Mongolia
I worked closely with Bo Cheung (aka Zhang Bo), of UFIND STUDIO, to locate all the best videos of this event, and it turns out the strewn field prediction landed over border of China’s Inner Mongolia, in the Jilin Province. Bo gave it a good effort and searched the area extensively with his team, along with help from local villagers and turned up nothing. This was a fairly large event, reported at 0.56 kilotons from The Center for Near Earth Object Studies (CNEOS), is part of the California Institute of Technology's Jet Propulsion Laboratory. CNEOS collects data from U.S. Government sensors, and releases it for research purposes. CNEOS data is available publicly at https://cneos.jpl.nasa.gov/fireballs/...., and it was caught on camera, turning night into day in the city of Songyuan.
There was a lot of confusion, on my part, in the early video analysis about the direction of travel of the meteor, because the shadows observed in videos did not seem to agree with the CNEOS data. In the end, it became apparent that my inexperience had caused me to think the meteor was moving away from the video location, because the shadows on the ground were getting longer. In fact, the meteor was toward the video location, but it was also getting lower in the sky, causing the shadows to get longer. Once that was resolved, all the video data agreed and we were able to determine a fairly precise trajectory.
CNEOS Accuracy Issues
The best data we had initially for this event was from the NASA Center for Near Earth Object Studies (CNEOS) database, which is sourced from a classified U.S. government sensor network (probably satellites). I haven’t personally worked on more than a few CNEOS events, but I had the impression that it was fairly accurate, at least within 10km. However, after spending a lot of hours analyzing videos for this event, I was surprised to find that the CNEOS trajectory was off by more than 100km! The attached KMZ file includes both ground tracks for comparison. More data is needed to characterize the capability of the system, but my opinion is that the accuracy is very much dependent on how many satellites observed the event and how close to the horizon the observations were. The elevation above the horizon is important because of atmospheric refraction, and this effect can add significant error. I have not been convinced that any studies have accurately characterized the refraction relation for meteors, because although many published works have characterized refraction for astronomical refraction and terrestrial refraction separately, none have combined the effects, as necessary for meteor travel. I perceive this as a weakness in all the available data, and it is well known that the ASGARD system also experiences significant error for measurements near the horizon.
Jilin Bulletin Posted
The attached bulletin includes my best estimate for the Jilin event, but I will also say that my confidence level is only high in the north-south direction. Bo gave me access to an excellent video from the town of Xingfacun, from which I was able to extract Trajectory data can be extracted from stars visible in a video or long exposure photograph of a meteor event. If stars in the video can be identified, then a very precise plane of travel can be determined. If stellar calibration is obtained from two videos with sufficient geographic separation, a very precise meteor trajectory may be calculated.... (plane of travel calibrated to stars visible in the video). Triangulation in the east-west direction was based primarily on video shadows from Songyuan and the shadows do not pinpoint the last light from the meteor, so it is possible that the strewn field is farther west. Final elevation of the meteor was at 14 degrees from the Xingfacun video, which puts the altitude at 15 km at the projected intersection point. Being such a large event, I would have expected Bo to be able to find Typically, meteoroids breaks apart during flight through the atmosphere. Much of the material evaporates in a process called ablation, leaving only small stones to find. Occaisionally, large meteor events can drop meteorites as large as several kilograms, but it is much more likely to find the smaller, more numerous fragments, in the 10 to 100 gram size range...., if we had the location correct. If you are interested in continuing the search, please contact me and I will give my best recommendation for additional search areas.
My name is Jim Goodall, and I am an automotive controls engineer in the Detroit area, but my passion is physics. I started this website as a hobby, to support the global network of meteorite hunters.
Feel free to contact me, if you have any questions about the products on this website. Jim Goodall | Hartland, Michigan, USA | email@example.com | +1 586 709 5888