Fireball Spotted over Texas

Great balls of fire indeed.
Folks from Oklahoma City to Houston reported having seen a fireball shoot across the sky at about 8 p.m. Wednesday, according to the Federal Aviation Administration. Astronomers said the fiery display was likely caused by a meteor or some other space matter hurtling through the atmosphere.
Texas observers blogged about the show and described it as a blue-green object trailing sparks.
In central Texas, Little River-Academy Police Chief Troy Hess said he had just pulled over a driver when he managed to capture video of the fireball from his cruiser.
"It kept getting bigger, and the color kept changing," he told the Austin American-Statesman.
No damage was reported from the fireball.
It was not clear whether any of the remnants fell to earth. Meteor sightings are common, with most burning up in the atmosphere and leaving scant debris, according to astronomers.
Anita Cochran, assistant director of the McDonald Observatory at the University of Texas, told the American-Statesman that Wednesday's fireball was most likely small space debris.
"The rare case is when it is something big," she said.
"It looked like a sparkler, almost," Lisa Coleman, who lives outside College Station, Texas, told local TV station KBTX.
"There was just this huge meteor-like rock falling across the sky and I thought, 'Wow, that's really huge to be a shooting star,' but it lasted about 12 to 15 seconds and it had a sparkling, flaring tail," Coleman said.
Texas A&M astronomy professor Nicholas Suntzeff told KBTX the meteor was not as huge as it appeared -- probably only about the size of a fist. He attempted to dispel some other meteor myths.
"If they do hit the earth, they are not hot, they are cold. ... There is the fire around them, but ... the meteor itself remains cold," Suntzeff said. "It almost never produces a fire when it hits the earth."
Suntzeff said the type of meteor that residents spotted, likely a bolide meteor, is both bright and rare -- most people will probably never see one again in their lifetime.
"Usually it's just a fraction of a second; here it was like five seconds or so. Again, I've only seen a few of those in my life. I wish I'd seen it," he said.
Another odd fact about this week's fireball: The sighting occurred on the ninth anniversary of the space shuttle Columbia falling to earth over east Texas.
[For the Record, 1:05 p.m., Feb.3: An earlier version of this post -- and its headline -- referred to the meteor as a meteorite. A meteorite is a portion of a meteor that reaches the Earth intact.]

http://latimesblogs.latimes.com/nationnow/2012/02/meteorite-sighting-oklahoma-texas.html

Strange Crystals in Meteor

Strange Crystals Reveal Rock to be Ancient Meteorite

By Nola Taylor Redd, SPACE.com Contributor
Space.com | SPACE.com – Tue, Jan 3, 2012

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A rock made of a type of crystal never before seen outside a laboratory is most likely a meteorite from the early days of the solar system, geologists say.

Two years after identifying the Russian rock's unusual composition, a team of scientists thinks it has nailed down its origin. The researchers say it is a quasicrystal formed under conditions far more likely in space than inside the Earth, and that its chemical composition of metallic copper and aluminum resembles what is found in so-called carbonaceous chondrites – the primitive meteoritesthat scientists think were remnants shed from the original building blocks of planets.

Crystals are symmetrical, neatly ordered patterns of atoms that repeat themselves regularly. They are found commonly in nature in different types of rock.

Thirty years ago, through experiments changing the structure of  crystals, laboratories began producing quasicrystals, a strange arrangement of atoms that repeats with two different frequencies rather than one. Rather than a simple ratio of, say, 2:1, the ratio of atoms in a quasicrystal is based on an irrational number, such as the square root of 2:1. (This year's Nobel Prize in Chemistry honored Dan Shechtman for his 1982 discovery of quasicrystals.) 

'A disharmony in space'

Researcher Paul Steinhardt of Princeton University describes such a bizarre arrangement as "a disharmony in space."

"Any symmetry thought to be forbidden is possible for quasicrystals," he told SPACE.com in an email.

The most familiar of such arrays is found on the face of a soccer ball, composed of 20 hexagonal faces with 12 pentagons interspaced.

Synthetic quasicrystals are used to strengthen steel and aluminum, or to create a Teflon-like materialthat is harder and nearly as slippery as the metals.

"At present, we have a limited menu of quasicrystals," Steinhardt said. "One of the reasons for conducting a search of natural quasicrystals is to see if nature found ones that have not yet been discovered synthetically by trial and error."

Quasicrystals in nature

In 1998, Steinhardt and his team began a systematic search for a naturally occurring quasicrystal, scanning databases of known crystals for patterns that resembled those of quasicrystals.

Each candidate sample was sliced and diced with X-ray and electron diffraction imaging techniques, Steinhardt said.

For eight years the team sought in vain. Then, in 2007, Luca Bindi of Italy's University of Florence offered his collection of minerals to the group for examination.

One of the rocks, which had been found in the Koryak Mountains in eastern Russia, was a perfect match. [5 Reasons to Care About Asteroids]

With the first naturally occurring quasicrystal finally found, the next step was to determine its origins.

Extraterrestrial origins

Bindi led a team of researchers in analyzing the quasicrystal rock's structure, which revealed that the rock must have had an extraterrestrial birth. The scientists reported their findings in the Jan. 2 issue of the journal Proceedings of the National Academy of Science.

Inside meteorites, which have been exposed to the environment of space, the ratios of oxygen atoms and their variations, called isotopes, are fixed by intense space radiation and cosmic rays.

But the interior of Earth shields elements from these rays, allowing materials inside Earth-bound rocks to mix and changing these ratios.

An examination of the oxygen isotopes in the Russian rock indicated that it must have originated in the early solar system.

"Now that we know that quasicrystals formed in the early solar system, we need to understand exactly how," Steinhardt said. "More material and more tests are needed to understand how nature has managed to accomplish the feat."

Wider samples

At the moment, however, the Koryak sample is the only known naturally occurring quasicrystal.

"My hope is that many more mineralogists, petrologists and meteorite experts will begin searching for natural quasicrystals as well," Steinhardt said.

Though the Koryak sample came from space, Steinhardt said that he doesn't believe that all quasicrystals necessarily do.

"There is no reason to believe that ours is the only natural quasicrystal, or that all quasicrystals are extraterrestrial," he said.

A wider sample could provide greater clues to how these strange crystals were created.

Old instead of odd

That such a crystal formed so long ago changes how scientists view quasicrystals.

"Until now, quasicrystals were thought to be oddballs, and one of the newest materials formed," Steinhardt said. "Now we know that is completely wrong. Quasicrystals are one of the first minerals to have formed in the solar system — in the top 250 — long before most of the common minerals found on Earth."

Their formation is probably not unique to the environment around the sun. Instead, quasicrystals may exist throughout the Milky Way and other galaxies.

"They are perhaps the most common mineral to have formed in the universe," Steinhardt speculated.

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FireBall Spotted over Ontario

Researchers at the Royal Ontario Museum and University of Western Ontario are asking for the public’s help to find fragments of meteoric fireball that were seen in the southern Ontario sky on Monday evening.

The UWO astronomers say fragments of the meteor likely fell just north of Peterborough, near the town of Selwyn near the eastern end of Upper Stony Lake.

The cameras recorded a slow-moving fireball, estimated to be no bigger than a basketball, around 6 p.m. on Monday near Lake Erie, which then moved north-northeast, said Peter Brown, the director of UWO’s Centre for Planetary and Space Exploration.

The cameras were able to track the fireball’s descent for about 10 seconds travelling at 14 km per second. The meteor continued to penetrate deep into the atmosphere at an altitude of about 30 kilometres, which meant the fireball was “massive,” Mr. Brown said.

“The long duration of 10 seconds, along with the deep penetration and low velocity are all rare things. It suggests strongly that some rocks survived and made it to the ground,” he said.

Scientists are not often able to link meteors a particular orbit of the solar system, but Mr. Brown said this meteorite is linked to the orbit between Jupiter and Mars.

“When we can put it into a spatial context, it forms a powerful data set,” he said. He described finding a meteorite from the fireball captured by video as the equivalent of studying samples brought back from a space mission – where knowing where the object comes from helps to inform scientific understanding.

Most of the meteorites date back to the inception of the solar system 4.5 billion years ago, said Ian Nicklin, the ROM’s mineralogy technician.

“They come from asteroids that were formed the same time as celestial planets such as the Earth,” he said. “A lot of them really haven’t changed much since that time, so they really are a glimpse back into our earliest periods of the solar system.”

Meteor recovery is rare in southern Ontario, Mr. Nicklin added. Most of the meteors crash into water bodies or in remote communities to the north.

“The last time we had a meteor like this was in 2009, when we put out a similar press release, and a lady came forward with a fragment that crashed into her SUV,” Mr. Brown said.

The fragments would likely be dark matte in colour and weigh no more than a few grams. The outer crust would appear melted and charred. People who think they may have found a meteorite fragment should contact the ROM, which is leading the recovery.

Rainbow Exploding Meteors spotted over D.C

Hordes of incandescent meteors have ripped across U.S. skies this past week. According to alert skywatchers, the nation's capital got in on the stellar action in a big way.

The delightful blog Lunar Meteorite Hunters carries two reports of a glowing nightly visitor that appeared between 40 and 60 miles south of D.C. on Monday, Nov. 28. The first account is from Patrick in Leonardtown, Md., who caught a bright object whizzing by overhead around 9:20 p.m. The flaming flier lasted about 2 seconds, cycling like anangry squid from red to blue to green. Says Patrick, with minor spelling/grammar errors fixed:

No discernible sound. Very bright, same as the moon. Not blinding, but quite noticeable. Not sure, [but it looked like it had] only one tail. I'm not sure if it was when it entered the atmosphere, but I saw almost an explosion or halo form around it about halfway through its travel before it disappeared.

A meteor that was hoisted with its own petard, you say? Go on!

The next account of Monday's space shenanigans comes from an unnamed observer in Stafford, Va., at approximately the same time of evening. This witness also says the object flamed out in a spectacular fashion:

Two seconds left to right. White, reddish. Brightest thing in the sky.... I thought it was a falling star but then it exploded with a bright flash of light. It look like it hit something and disintegrated. There was a big puff of what look like smoke.

The forums of the American Meteor Society bear no similar reports of a Monday-night fireball near D.C., but resident site expert Robert Lunsford notes a number of minor meteor showers that might account for the sparking skies. The Andromedid shower is still ongoing with "low, but detectable" and slow-moving meteors, and the November Orionids reached their anthill peak on Nov. 30. A dimmed, crescent moon is allowing amateur astronomers in the Northern Hemisphere to see as many as four shooting stars an hour, Lunsford says.

So keep your eyes open and you might just see one of these eerie travelers from the beyond. However, best know how to distinguish between a meteor and a helicopter, first.