Jagpal Singh Top 10 Meteorites ~ All About Astronomy

Wednesday 27 February 2013

Top 10 Meteorites

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It's a little bit terrifying to think that there are giant rocks, flying straight at our planet, on a regular basis, but it's true.
Good thing we've got our atmosphere to help fry the occasional wayward piece of asteroid or comet as it heads our way … but once in a while, and handful (or more) make it through and we get everything from pretty shooting stars to terrifying meteor fireballs, not to mention the occasional nice-looking extraterrestrial rock.

1: Tunguska Event


The meteor that flew through the earth's atmosphere in 1908 over Siberia exploded just a few miles from the Siberian surface.
The explosion had the force of an atomic bomb and flattened some 800 square miles of trees. It took years for scientists to begin investigating in the remote, unpopulated area; one hundred years later, they're still looking for conclusive evidence of a strike, in the form of a crater or meteor fragments.
Some now believe a nearby lake may conceal a crater. And recently, some decidedly stranger theories on Tunguska have popped up, with one claiming an alien spaceship destroyed the earth-bound comet just before it hit in an attempt to spare our planet destruction. Huh.
Special Honorable Mention: KT Extinction meteorite
You know, it's the asteroid that may have killed the dinosaurs … and over half off all the species on the planet. Scientists aren't 100 percent sure that an asteroid caused the so-called "K-T Extinction", but they have some good reasons to believe that the culprit came from outer space.
Most of the soil deposited during the time of the extinction (known as the K-T layer) has an awful lot of Iridium in it, something that isn't so common on earth, but it sure is on asteroids.
Scientists figure sometime around 65 million years ago, the earth was hit by one or more Iridium-filled meteors or comets, triggering atmospheric dust and widespread climate change. And where did this massive meteorite hit?
No one's sure, but some researchers believe a crater on the Yucatan peninsula in Mexico may mark the spot.

2: Hoba Meteorite


Weighing in at, oh, sixty tons, the Hoba meteorite, which still resides where it touched down in Namibia, is the largest known meteorite on the planet. The flat slab of iron fell to earth sometime around 80,000 years ago, so we don't really know what kind of pyrotechnic show accompanied its arrival, but it took until 1920 for humans to come across it, when a farmer plowing his field came across its metallic top just below the surface. Since then, the Hoba site has become a national monument, drawing thousands of visitors each year.

3: Willamette Meteorite


Weighing in at somewhere around 15 tons and ten feet tall, this massive, pitted iron meteorite is believed to be the remains of the iron core of a planet that was involved in a collision billions of years ago.
It landed on our planet a mere thousands of years ago, and while it wasn't "discovered" by Westerners until 1902, the meteorite had long been revered by the Native American Clackamas tribe as a healing source called Tomanowos.
These days, Tomanowos rests at the American Museum of Natural History in New York City (as it has since 1906), but the tribe recently struck a deal with the museum, allowing the meteorite to remain on display so long as the Clackamas can visit for ceremonial purposes.

4: Sikhote-Alin


When this massive iron meteor roared out of the sky in February of 1947, witnesses said it was brighter than the sun. And when an explosion ripped it apart as it fell to earth, it rained down fragments across a half-mile square in the Sikhote-Alin mountains in Siberia.
The entry and explosion were visible as far as two hundred miles away. Over the years, meteorite hunters have descended on the area in search of the distinctive, slightly metallic, pock-marked, twisted and curved iron speciments.
Smaller Sikhote-Alin fragments are still selling today. Get yours while they last.

5: Sylacauga/Hodges Meteorite


Sometime in the fall of 1954, while a 31-year-old Alabama housewife named Ann Hodges napped on her sofa, an eight-and-a-half pound meteorite was roaring through the sky.
Moments later, it smashed through her roof and smacked her on the hip. That'll teach you to sleep on the job (kidding).
Luckily, Hodges was left bruised but otherwise unharmed by the grapefruit-sized rock, which her neighbors described as a fireball shooting through the sky. Hodges became a minor celebrity and later donated the meteorite to the Alabama Natural History Museum.
More recently, a German boy claimed he too was hit by a meteorite while walking to school in June of this year. The 14-year-old German student said he saw a flash of light just before he was hit by the pea-sized meteor. Who knew a pebble could be so dangerous?

6: ALH 84001


It's such a catchy-sounding name, right? Well, the actual meteorite is far more impressive than its generic-sounding name.
ALH 84001 (let's call it "Al" for short) was discovered in Antarctica in 1984, some 13,000 years after it arrived from Mars.
Yes, Mars.
Al was born from the lava of a Martian volcano about four and a half billion years ago. It then sat on the Martian surface until about 15 million years ago, when another asteroid or meteorite knocked it free, sending it hurtling towards earth, where it landed in the Allan Hills of Antarctica.
Buried inside Al was evidence of possible early Martian life, in the form of fossilized remains of what may have once been some very, very small bacteria. It turns out Al was kind of an interesting guy, for a rock.

7: Orgueil Meteorite


The Orgueil meteorite burned through the atmosphere in May of 1864, disintegrating into 20 pieces on its way to Orgueil, France.
The fragments were soft enough to be cut with a knife and soon the Orgueil samples had made their way to museums around the world.
Since then, the Orgueil meteorite's caused nothing but controversy, with scientists speculating that its organic material might be proof of extraterrestrial life and puzzling over what looked to be fossilized remains in the meteor. Exciting stuff right?
Not really. While the meteorite itself was real, its signs of life were a fraud.
The culprit? Some pollen seeds glued onto the space stone with a little coal dust. Not so out of this world at all.

8: Peekskill Meteorite

In 1992, the Peekskill meteorite streaked across the sky in a greenish blaze from Kentucky to Pittsburgh, all the way to Peekskill, NY , where it attacked a perfectly innocent parked car.
The 1980 Chevy Malibu, which survived with only a massive dent and later went on to tour the world as the car who survived a meteorite attack. While the meteorite had impeccable aim, it was otherwise quite ordinary: about the size and weight of a bowling ball, although not so round, and made up of the most common type of meteorite stone.
What was unusual was the degree to which the Peekskill meteor was studied. Because its trail took it across much of the east coast, its path and trajectory were caught on video and analyzed by scientists, making its orbit, entry and impact one of the most analyzed ordinary meteor strikes ever.

9: Murchison Meteorite


The Murchison meteorite broke into hundreds of pieces as it fell over Australia in September of 1969.
The largest of the pieces was over one hundred pounds, while the smallest were less than one pound.
It streaked to the ground in a massive fireball, trailed by a hazy tail, before it broke into fragments… and those fragments have been extensively studied ever since.
It turns out that the Murchison meteorite contains a wide array of amino acids, the building blocks of life, making them of particular interest to curious astrobiologists.


10: Allende Meteorite


The Allende meteorite that crashed to earth in 1969 over Mexico broke up into hundreds of fragments that, all put together, would weigh several tons. Since then, those fragments have become collector's pieces.
Many of the black stone pieces are covered by a glassy exterior formed by the high temperatures during entry into our atmosphere, and scattered throughout Allende's ancient fragments (the meteor contains particles that may be older than the solar system) are olivine and even microscopic diamonds.
After all, why should stars be the only ones who get to sparkle?


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