Mon, 30 Nov 2009 22:00 UTC
A lot of what people thought is turning out to be wrong. The Nov. 18 fireball was apparently much higher and farther away than it appeared, never closer than 120 miles to Salt Lake City, which makes its brightness all the more amazing.
Dash-cam video from a police car in Grand Junction, Colo, provided vital clues to meteor trackers. Almost 300 miles away, it shows the fireball lighting up the sky, all the way on the opposite side of Utah.
Seth Jarvis of Clark Planetarium calls it God's flash bulb, briefly illuminating a half million square miles.
"From our area here, it was as bright as the sun," he said.
In surveillance video from the Salt Lake valley, the Wasatch Mountains turn from midnight to noon, as if a zillion-watt light bulb switched on.
"In the trillions of watts of power, which is a fair percentage of the power being consumed by the United States of America," Jarvis said.
Meteor trackers measured the angles of moving shadows in video of the meteor. Using textbook trigonometry, they worked out the angle and trajectory of the meteor.
"I'm estimating it entered the atmosphere at about 50,000 miles an hour," Jarvis said.
With the Colorado video and a spectacular mountaintop video from western Utah, they triangulated a new target zone. The space rock evidently traveled north to south and exploded 35 miles high, 120 miles west of Salt Lake.
If any of it reached Earth, it was likely south of Wendover, near the Utah-Nevada border in the rugged Deep Creek Mountains.
"Which is a pretty nasty place to have to go hunt for rocks, because there's plenty of rocks already out there," Jarvis said.
Professional meteorite hunters have also done the same calculation, and teams of searchers are already in the Deep Creek Mountains.
Photos taken the next morning seem to show two smoke rings. It may be an echo of the double flash or double explosion noticeable on some videos.
Jarvis explained, "There's lots of other natural phenomena that can create interesting looking clouds that high up in the sky. And it could be military jets maneuvering, any number of things; however, there are a lot of things that sort of line up in favor of that being the smoke trail left by the meteor."
Jarvis says meteors like this enter the atmosphere all the time but usually over oceans, uninhabited ground, or at times when no one is looking. For a populated place like Utah, the Nov. 18 event was practically a once-in-a-lifetime experience.