COSMOS 1484 Deorbit 28 Jan 2013 0228 UTC

Confidence of Recoverable Meteorites (CRM) on a 1 to 10 scale (10 is highest probability of meteorites): Meteorites: 0, Satellite Parts: …8?
Reasons for this score: No meteorites will be found from this event! *But material may be found – this is a spacecraft re-entry. The old Soviet COSMOS 1484 satellite de-orbited over the eastern US, leaving a trail of debris that stretches from Ohio to Georgia and appears in dozens of radar images. Eyewitness accounts near Atlanta include reports of sonic booms, indicating that at least one large mass probably reached the ground. This satellite weighed 2500 kg (~5500 lb!) so large objects might be found from this event.

Google Earth Overlay: (Be warned! This may melt your computer!) LINK

Reports of this event can be found in multiple sources (LINK, LINK, LINK for example). This event features many eyewitnesses, although some areas – such as Cleveland, OH where the satellite passed directly overhead – were overcast at the time and no eyewitnesses record the event. This event produced an enormous amount of radar data, to the point that we probably haven’t located it all.

COSMOS 1484 track 01Figure 1: Ground track of Cosmos 1484 (light red line, travel direction is north to south) and radar returns. Every square in this image contains at least one radar signature of falling material.

Satellites are different from meteorites in that they take longer to fall apart and cover a much longer strewn field. Pieces on the outside of the satellite break off first, probably preferring low-density structures like solar panels and support scaffolding. These items should have wound up on the ground on the northern end of this strewn field, and relatively dense, robust objects continue downrange to wind up at a more southerly location. The radar returns along the WV/KY border consist of a large number of relatively small pieces, and these may be difficult to find. Not all are small, however.

Ohio 01Figure 2: Relatively large radar return just south of Frazeysburg, OH. This appears relatively early along the path and may be an external piece with low density, such as a solar panel.

KY 02Figure 3: Another relatively large radar signature with a strong reflectivity value. This piece likely reached the ground in the vicinity of Ulysses, KY.

Spacecraft fragments make wonderful radar targets. They are angular, which helps reflect radar pulses from any direction, and they are metallic which lends itself to strong reflections. Modeling their flight to the ground, however, is exceedingly tricky. We can model the dark flight of meteorites fairly accurately because we know their density and can assume that they are something close to spherical. Metallic (or fiberglass, or carbon fiber, or…?) satellite fragments will probably have some high surface-area shape that will give them difficult-to-predict aerodynamic properties. We can attempt this, and if anyone has a particular piece from this event that they’d like a model for, let us know and we’ll post it here.

Additionally, an eyewitness reports sonic booms east of Atlanta along with a flight path description that perfectly matches the last expected orbit for COSMOS 1484. This means that a large mass penetrated deeply into the atmosphere but was still moving at supersonic speeds. We predict that this large mass (or masses) should have reached the ground somewhere southeast or south of Atlanta, along the ground track shown here. We can only constrain the landing point if videos of the fireball become available.

All work presented here is protected by copyright ©(2013) Galactic Analytics LLC. Authors of this work include Marc Fries, Robert Matson, Jake Schaefer and Jeffrey Fries.

One comment on “COSMOS 1484 Deorbit 28 Jan 2013 0228 UTC

  1. Thanks, Marc & company, for posting this deorbit.
    I know some people will say, “Wait a minute! this isn’t a meteorite-fall.” But that doesn’t matter to me. I’ve always wanted to find some man-made space-debris. In any case, this will be great practice to hone our recovery skills. And the good news is that this space-junk doesn’t belong to NASA!
    Wonder how long until we see COSMOS 1484 “meteorites” on eBay? ;-)
    Too bad the Tucson Gem & Meteorite Show is distracting attention away from this event.
    Most of the professional meteorite-hunters are at that Show, now, which means there’e no competition for those MIB who never share their strewn-field data! :-(

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