FIREBALL MANIA: Runners in Sunday's Austin marathon were astonished when a brilliant fireball raced across the Texas sky in broad daylight. The extremely-bright meteor descended at 11 am CST on Feb. 15th less than a day after the FAA reportedly warned U.S. pilots to watch for "falling space debris" from the recent satellite collision between Iridium 33 and Kosmos 2251. Click on the image to launch a News 8 Austin video:Click to view fireball videohttp://spaceweather3.com/What you just saw was not satellite debris. The high speed of the fireball in the News 8 video is typical of a natural meteoroid hitting Earth's atmosphere at tens of km/s. Orbital debris, on the other hand, should crawl across the sky at a fraction of that speed. Astronomer Bill Cooke of NASA's Meteoroid Environment Office has analyzed the video and confirms "it's a natural meteor, definitely." According to Cooke's analysis, the source of the fireball was a meter-class asteroid traveling at about 20 km/s.Fireball mania started on Friday the 13th, around 10 pm EST, when people in central Kentucky heard loud booms, felt their houses shake, and saw a fireball streaking through the sky: reports. "The world appeared to explode--in green!" said one eyewitness. Once again, this appears to be a natural event caused by a meteoroid. Iridium 33 and Kosmos 2251 collided at a speed of about 10 km/s or 22,000 mph. None of the surviving fragments should have been big enough to shake houses in Kentucky. Furthermore, US Space Command, which monitors objects in Earth orbit, has not announced a reentry over Kentucky on Feb. 13th.THIS JUST IN: On the evening of Friday the 13th, around 2003 UT, multiple cameras in Italy recorded a fireball at least 10 times brighter than a full Moon. Astronomer Diego Valeri sends this movie from Rieti. (Note: DivX is required to view the movie.) Ferruccio Zanotti of Ferrara recorded that same fireball and two others. Italian scientists are plotting the trajectory of the brightest fireball to estimate where it might have hit the ground; a meteorite hunt will soon be underway.