WACO (February 16, 2009)--The Federal Aviation Administration said Monday the fireball that streaked across the Central Texas sky Sunday, producing a series of window-rattling sonic booms, was a natural phenomenon and not debris from two satellites that collided in orbit last week.
Astronomer Preston Starr, the observatory manager at the University of North Texas, said he thinks the object was a carbonaceous meteor "about the size of a pickup truck."
He said it was a "slow mover" and probably has the consistency of concrete.
Starr said objects as large as the one spotted Sunday enter the atmosphere about eight or 10 times a year.
The Texas Meteorite Lab, which investigates such incidents worldwide, said, however, that it’s rare during daylight hours for a fireball to be visible.
The FAA Monday backed off its weekend claim that the fireball was caused by falling debris from colliding satellites plummeting into earth's atmosphere.
Earlier Monday, the U.S. Strategic Command said that the source of the fireballs and sonic booms wasn’t debris from the satellites.
The FAA notified pilots on Saturday to be aware of possible space debris after the collision Tuesday between U.S. and Russian satellites.
The FAA posted a notice to pilots on Saturday that “until further notice…a potential hazard may occur due to the reentry of satellite debris into the Earth’s atmosphere.”
“In the interest of flight safety,” the notice said, “it is critical that all pilots/flight crewmembers report any observed falling space debris to the appropriate (air traffic control) facility.”
The chief of Russia's Mission Control says clouds of debris from the collision will circle Earth for thousands of years and threaten numerous satellites.
The two communications satellites collided Tuesday in the first-ever crash of two intact spacecraft in orbit.
The collision occurred Tuesday nearly 500 miles over Siberia, producing a pair of massive debris clouds, according to NASA.
The collision involved an Iridium commercial satellite, which was launched in 1997, and a Russian satellite launched in 1993 and believed to be non-functioning.
Each satellite weighed more than 1, 000 pounds, officials said.
There were no reports Sunday of injuries or damage, although several small grassfires broke out around the same time as the explosion.
It wasn’t clear whether the space debris ignited those fires.
Some area residents saw the falling debris Sunday morning.
Jetta Hicks was driving on FM 1624 west of Calvert when she said she saw something burning in the sky, falling at a 45-degree angle.
She said it had a tail and appeared to be flaming.
She said she didn’t see anything hit the ground.
A resident of the Hubbard area reported seeking smoke high in the air at the time of the explosion and a camper at Mother Neff State Park in Coryell County spotted smoke from the falling debris.
Another witness who was in the Belton area described seeing “a ball of fire coming out of the sky.”
Residents reported feeling the explosion from the Marlin area north to Corsicana.
Authorities checked on reports of debris in the Leroy area early Sunday afternoon, but none has been found so far.
Law enforcement agencies were advised Sunday to contain the debris so it can be tested to confirm it came from the satellites.
Residents who find debris should leave it where they found it and contact a law enforcement agency.
What witnesses saw was reminiscent of the disintegration of the shuttle Columbia during reentry 39 miles above Texas on Feb. 1, 2003.
The disintegrating shuttle left a path of debris that stretched from the Dallas-Fort Worth area to Louisiana.
The debris field covered more than 28 thousand square miles in 33 Texas counties.
Investigators later determined that a chunk of foam the size of a suitcase tore a hole in Columbia's left wing 82 seconds after liftoff.
The breach allowed superheated gasses to enter the wing as the shuttle reentered the atmosphere at a speed of more than 12,000 miles an hour.
On Tuesday, February 10, the American civilian communications satellite Iridium 33, launched in 1997, and the defunct Russian military communications satellite Kosmos-2251, launched in 1993, collided over Siberia. Five days after the collision, reports have surfaced that burning debris from the collision has been spotted over several U.S. cities from New Mexico to Kentucky.

Calls to 9-1-1 began to come in to Williamson County, Texas sheriff's office around 12:30 p.m. (CT) that burning debris and fireballs were seen falling from the sky onto parts of Austin, Houston, Waco and San Antonio. Residents reported their homes and windows shaking and large explosions. After a search of several areas, the Williamson county sheriff's office reported that no debris or impact sites were found. Earlier unconfirmed reports had said the debris could have been the result of a small plane exploding. 
Iridium satellite. 
Steve Thornton, a resident in Austin told KEYE-TV that he "saw something burn up in the atmosphere going east to west at 40 degrees in the horizon looking north" which was "about the size of a half moon and as bright as a welders torch".  Other residents reported to KEYE-TV that they saw an "egg-shape with an orange center and bluish outer aura; a silvery-white tail."  Some report the incident lasting about 10 minutes.

On February 13, the National Oceanic and Atmospheric Administration (NOAA) issued an alert following reports of "explosions and earthquakes" along with "flashes in the sky" in Jackson and Louisville, Kentucky. There were no injures and authorities could not locate any damage.

"The Federal Aviation Administration (FAA) reported to local law enforcement on Friday that these events are being caused by falling satellite debris. These pieces of debris have been causing sonic booms, resulting in vibrations felt by some residents, as well as flashes of light across the sky," said the NOAA in a public information statement on February 13. The FAA also warns that the debris could cause damage to aircraft in areas reporting falling debris.

"Aircraft are advised that a potential hazard may occur due to reentry of satellite debris into the Earth's atmosphere. It is critical that all pilots/crew members report any observed falling space debris," said the FAA on February 13. Both the NOAA and FAA alerts are in place until further notice and cover an area from New Mexico to Kentucky.

However, Dr. Marco Ciocca, a professor at Eastern Kentucky University told WKYT in Kentucky it would "be months" before any of the satellite wreckage enters the Earth's atmosphere. "The debris doesn't simply fall out of its orbit. It will either vaporize or stay in orbit for some time before falling into Earth's atmosphere." 

The satellites, both of which weighed in excess of 1,000 pounds, and traveling at approximately 17,500 miles per hour, collided 491 miles above the Earth. Scientists say the explosion caused by the collision was massive. They are still trying to determine just how large the crash was and how the Earth will be affected. The United States Strategic Command of the U.S. Department of Defense office is tracking the debris. The result of plotting analysis will be posted to a public website.