DETROIT - It’s the astronomical event that has captivated southeast Michigan! Shortly after 8:00 p.m. Tuesday night, a large meteor hit Earth’s atmosphere. Small meteors, the size of a Grape Nuts nugget, hit Earth all the time, and those cause the normal "shooting stars" we sometimes see. But what hit Tuesday night was no small nugget.
I was in touch with NASA’s Marshall Space Flight Center this afternoon, and Dr. Bill Hooke, director of the center’s Meteoroid Environment Office, says that the rock that entered our atmosphere is now estimated to have been six feet in diameter. Something else important about this event is the meteor’s speed. Those little nuggets that cause our annual meteor showers travel at an average speed of 160,000 mph. Tuesday night’s meteor was much slower, perhaps around 28,000 mph.
"This fact, combined with the brightness of the meteor, shows that the object penetrated deep into the atmosphere before it broke apart (which produced the sounds heard by many observers)," according to NASA. As a result, some pieces of the meteor may have reached the ground after it broke up.
Earlier today, information that came into our newsroom suggested that those pieces may have been on a trajectory toward Macomb County, but we now know that Livingston County (possibly eastern Ingham County) is the likely target, as the meteor streaked from east to west on a path roughly from Brighton to past Howell. Here’s NASA’s track showing that path, and the little people on the map are reported sightings as posted on the American Meteor Society’s website.
So how bright was the meteor? So bright that our newest weather satellite, GOES-16, detected it. The satellite has an instrument called the Geostationary Lightning Mapper (GLM), and the meteor showed up! Here’s that GOES-16 image, zoomed in real tight. The circled area in the upper left shows two pixels that appear like lightning to the satellite’s detector.
The meteor also caused a big boom when it exploded that many people heard and some people even felt. Contrary to what you may have heard, this meteor did not directly cause an earthquake. Rather, the mild shake you may have experienced was equivalent to a 2.0 magnitude earthquake, but it wasn't an earthquake itself, which is caused by shifting tectonic plates beneath the earth’s crust. However, the University of Michigan’s seismograph did detect the "boom," take a look at what it looked like on that instrument:
If you decide to go meteorite hunting in Livingston County or eastern Ingham County, remember that meteorites contain metal, so a metal detector will be hugely helpful, especially since you’ll likely never see the space rock with the snow pack out there. If you find what you think is a meteorite, here’s a three-step test to see if you might have one:
- If it’s much heavier than you would otherwise expect, then that’s a good sign!
- Since most meteorites have some iron in them, they are magnetic. If you have a good magnet and the rock is attracted to it, you’re getting warmer.
- If you pass steps one and two, you’ve made it to step three: rubbing the rock on a streak plate. Since you don’t have a streak plate like I do, you can use the rough underside of the lid of your toilet tank. Scratch the rock on there and, if it leaves a DARK streak, then it’s probably not a meteorite. However, if the streak is light or faint, then you might have one.
If you plan on meteorite hunting, do it safely, and please respect peoples’ private property. If you do find one, let me know. I can check it myself, and then recommend you to a scientist who can give us official confirmation.
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