November 28, 2002 Fireball (Thanksgiving Fireball)

This extremely bright meteor was seen by residents of Colorado, Kansas, Nebraska, Wyoming, and Utah at 6:21 PM MST. Some sources reported it early on as a piece of decaying space debris. However, no large objects decayed over Colorado at this time. The fourth stage of a Russian rocket did decay about 12 hours earlier over the Pacific Northwest, but this was a different event.

Meteor PathIt has been possible to determine quite accurately a great deal of information about this meteor.

Images of the event were captured on two of the DMNS allsky cameras, operating at Kent Denver School in Englewood, CO, and at Montrose High School in Montrose, CO. Additional images were captured on an allsky camera in Albuquerque, NM operated by Sandia National Labs, an allsky camera in Platteville, CO, and a security camera at Xilinx Corporation in Longmont, CO.

In addition, nearly 350 witness reports were submitted to this website, many with accurate measurements.

As a result of this wealth of information, it has been determined that the fireball probably began several miles southeast of Sapinero, near Blue Mesa Reservoir in Gunnison County, CO. The meteor was at least 60 miles high when it first became visible. It descended steeply downwards, experiencing a major flare just north of the Gunnison River, about 23 miles above the Montrose-Gunnison county line. The meteor burned out 13 miles over the Gunnison River, near Poverty Mesa. The large flare was much brighter than a full moon. By measuring the brightness of the meteor over its path (as captured on camera) I estimate a total energy for this event of at least 2.4 tons of TNT. This is consistent with an entry mass of about 200 pounds. Much of it would have burned away, but it is quite possible that many pounds of meteorites were deposited on the ground along the last of its path, and extending perhaps as far as Montrose. The meteor appears to have been traveling at about 16 km/s (36,000 mph) when it first entered the atmosphere, which is fairly slow. You can click on the above image for a larger view of the ground path.

The parent body originated from the direction of Andromeda (radiant RA=6°, dec=31°.) This is quite close to the radiant of the Andromedids, a minor meteor shower active from September 25 to December 6. The high altitude of the initial breakup (23 miles) and the apparent high luminous efficiency (>10%) suggest the possibility that this meteor consisted of weak cometary material, and may indeed be a remnant of Comet Biela (1852 III), the parent of the Andromedids.

Witnesses in an area about 30 miles around the ground path reported loud sonic booms. Additionally, I have two reports of electrophonic noise, which is sound that occurs simultaneously with the fireball, and is presumably some type of poorly understood electromagnetic phenomenon.

Witness Reports
Witness reports were received from a wide area. Each small, numbered square is a single report. Those that were particularly useful for deriving bearings have lines plotted towards point where the fireball terminated.

Terminal Area
This map provides an analysis of the fireball path based on camera data. Images were captured on two allsky cameras operated by schools in the DMNS network (Montrose High School and Kent Denver School), by two independent allsky cameras (Platteville and Sandia), and a security camera at Xilinx Corporation in Longmont. The cameras with the best calibration are at Montrose, Sandia, and Platteville.

Elevation data from the cameras suggests that the meteor began at an altitude of about 60 miles, a few miles south of Blue Mesa Reservoir, and descended slightly to the north of west to an area several miles east of Montrose. It stopped burning at a height of about 13 miles.

Montrose VideoSix frames from the Montrose video capture the fireball over about 8 seconds of flight. Large meteors normally explode at the end of their flight. The large explosion in the middle, followed by several seconds of luminous flight, is unusual.

You can click on this image for a larger view.

Acoustic Range
Based on preliminary data provided by an infrasound monitor operated in Erie, CO by NOAA, I have determined a range from the detector to the fireball path of 284 km, which agrees nicely with the center of the path determined from the cameras and witness reports. The signal was very weak for such a bright meteor, which suggests a high luminous efficiency and therefore a fairly fragile meteoroid.

Los Alamos National Labs also operates several infrasound detectors. They should soon be in a position to provide additional information about this meteor, particularly in regards to its entry mass.

The Department of Defense operates Earth monitoring satellites designed to detect rocket launches. These satellites sometimes record large fireballs. If this meteor was recorded, it is possible that this information will be made available in the next few weeks.


If you saw this fireball and didn't file a report, please do so here. Please read the press release provided by the Denver Museum of Nature and Science.
Acknowledgments:
  • Platteville Allsky Camera Image: Bifford P. Williams, Colorado State University
  • Sandia Allsky Camera Image: Joseph C. Chavez, Sandia National Labs
  • Infrasound Data: Alfred J. Bedard, NOAA/Environmental Technology Laboratory
  • Xilinx Security Video: Xilinx Corporation, San Jose, California
  • Montrose and Kent Denver Allsky Camera Images: Denver Museum of Nature and Science
  • Satellite Elements and Decay Data: National Aeronautics and Space Administration

© Copyright 2002, Chris L Peterson. All rights reserved.