Weekend Fireballs
On Saturday night, Dec. 1st, around 10:15 p.m. CST, a sensational fireball glided over the US Midwest. Automobile traffic stopped. Airline pilots peered in amazement through cockpit windows. And emergency phone lines were jammed.
Right: Airline passenger Rick Bordignon snapped these photos of the fireball from a window seat on US Airways Flight 612 from Philadelphia to Las Vegas.
"It was breathtaking!" said Greg Bakker of Hull, Iowa. "My wife and I were driving home around 10:30 CST when I saw the lights. I pulled the vehicle to the side of the road and we sat there awestruck. There were about 8 objects -- fiery yellow in color and slow-moving, much slower than any of the Leonid meteors I saw last month."
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Rick Bordignon was in a commercial airliner bound for Las Vegas when he saw them. "I was looking out the left window into the starry night when I noticed an approaching light," he recalled. "I was thinking... Hmmmmm, looks like a missile. But rather than raise a general sense of panic by yelling 'Incoming!,' I did the next best thing and got out my camera.
"I snapped one picture (above), but my camera is poor in low light. So I stopped to adjust the settings. When I looked out again I was amazed by what I saw: hundreds of objects with colorful glowing tails! So I snapped another one (inset) but it only picked up the brightest fragments -- and it was shaky, too.
"When I got off the plane, I tracked down the pilot. He said every pilot in the Midwest saw it and it was the 'buzz of the frequencies.' They had never witnessed anything like it before."
Right: Saturday's brilliant fireball seemed close at hand to many who saw it. In fact, it was at least 50 km higher than a high-flying jet airplane. This rendering of Rick Bordignon's view from a window seat on US Airways Flight 612 was created by T. Phillips.
The eye-catching display had actually begun hours earlier. Alan Pickup, a satellite decay expert who works at the United Kingdom's Astronomy Technology Centre at the Royal Observatory in Edinburgh, explains:
"The rocket, a Proton or 'SL-12', was launched from the Baikonur Cosmodrome in Kazakstan at 18:04 UT on Dec. 1st. An 800 kg metal casing from the fourth stage of the rocket was on its third orbit around Earth when it burned up in the atmosphere over southern England and France at about 22:35 UT."
Welshman Chris Evans was just stepping out of a restaurant in the French countryside when the casing soared overhead. "At first it was a single large fireball," says Evans, "but then it broke into about 30 or 40 smaller ones, like a giant fireworks display. It was absolutely magnificent." Other observers in the region noted a lingering trail and a "smoky halo" around the Full Moon.
Below: This schematic diagram shows the two pieces of a Proton rocket that disintegrated in Earth's atmosphere on Dec. 1st and 2nd: the 800 kg 4th-stage casing and the 4200 kg 3rd-stage rocket. Image courtesy Mark Wade and the Encyclopedia Astronautica.
Meanwhile, another even bigger piece of the rocket -- its 4,200-kg third stage -- was decaying. The third stage hadn't dropped as fast as the casing had done. But finally, about six hours later, it too began to glow.
Shannon Rudine at the University of Texas McDonald Observatory spotted the rocket at 10:18 p.m. CST on Dec. 1st (0418 UT on Dec. 2nd). "When I first noticed it, it had already broken into dozens of slow-moving incandescent fragments. Several were brilliant white, each nearly as bright as the planet Jupiter," he recalled
The flaming debris continued from there northeast over Oklahoma, Kansas, Nebraska, Missouri, Iowa and South Dakota -- dazzling thousands of onlookers along its path.
Many witnesses saw the fireball because it moved in such a leisurely way across the sky. There was plenty of time to pull over and step out of the car, or call a friend to the window. What a change of pace from the Leonids! Genuine meteors zip across the sky in a few seconds or less. The difference is mainly speed: Manmade space debris returns to Earth traveling 7 or 8 km/s, while Leonid meteoroids strike the atmosphere at 72 km/s -- ten times faster.
Furthermore, meteoroids, which are fluffy bits of comet dust, are mostly smaller than grains of sand and less massive than a gram. They disintegrate quickly. A Proton rocket, on the other hand, weighs thousands of kg. Such a massive object can burn and glow for a long time, especially when it skims almost horizontally through the atmosphere as this one did.
Even so, some sky watchers missed the spectacle.
"I was sitting in my living room on Saturday night when I heard a thunderous boom," says Matt Hilger of David City, Nebraska. "It was loud, but not quite loud enough to pull me away from Sports Center on TV. Moments later, a friend phoned to tell me about the event, but," he lamented, "it was too late...."
"Next time I hear a sonic boom late at night," he says, "I'll definitely look out the window."
Editor's note: After this story was published we received reports that sky watchers in New Mexico also saw the fireballs, adding to the list of US states already mentioned above.
Web Links & More...
Orbital Debris -- Learn more about space junk -- decaying and otherwise -- from this excellent web site at NASA's Johnson Space Center.
Above: Astronomer and engineer Stan Nelson recorded a powerful radar echo from the decaying Proton rocket on Dec. 2nd at 0417 UT. The 217 MHz radar signal was transmitted by the Naval Space Surveillance Radar in Kickapoo, Texas. Nelson detected the echo using a ham radio located in Roswell, New Mexico.
Weekend Meteors -- (Science@NASA) A little more than a year ago, sky watchers in Texas saw another Proton rocket fragment decay. Read all about it!
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