What was fire in the Texas sky? A metallic meteorite Metallic meteorite likely sent fireball across Texas sky

Sunday’s great Texas fireball was – probably – just a meteor.

Officials with the Federal Aviation Administration and the U.S. Strategic Command said the bright lights witnessed over Texas skies were almost certainly not linked to last week’s collision between an American commercial satellite and a Russian government communications satellite.

“Our indication is this was a natural phenomenon, perhaps something like a meteor,” said Air Force Maj. Regina Winchester, a spokeswoman for the Space Surveillance Network, part of the Pentagon’s Strategic Command arm that tracks space debris.

The brightness of the object and the fact that it seemed to generate a sonic boom led some astronomers to speculate about the meteor’s size.

“There are lots of variables, but we do have some clues,” said Anita Cochran, assistant director of The University of Texas at Austin’s McDonald Observatory.

The most common type of meteors are porous, nonmetallic and tend to fall apart quickly. Yet to generate a sonic boom, a meteor must reach Earth’s stratosphere, about 30 miles above the planet’s surface, before burning up, Cochran said.

That implies the meteor seen above Texas was probably a metallic-type, which, although rarer, are more durable during the fiery entry into Earth’s atmosphere. Metallic meteorites are the type most commonly found on Earth because of their durability.

Images of the meteor suggest it appeared brighter than a daytime Venus, Cochran said, but not quite as bright as a daytime moon.

A metallic meteorite of this brightness in the stratosphere probably would be about the size of a basketball, or smaller, she said.

And that’s just about how large it would have to be for any fragment to reach the ground.

There have been no reports of a discovery yet. Cochran said it’s almost impossible to triangulate the location of a meteorite from observations of its flight. Most discoveries happen by dumb luck, and they’re usually made in the world’s least populous continent – Antarctica.

“It’s just because black rock is easy to spot against white ice,” she said. “And if you see a rock there, chances are it came from space.”

eric.berger@chron.com

mark.carreau@chron.com