METEORITES AND TEKTITES


 
 

Meteorites

     When you see a falling star, it's not really a star.  It's a meteor burning up on entry into our atmosphere.  

     What's the difference between a meteor, meteorite and meteoroid?  A meteoroid is a solid celestial body floating in space.  A meteor is what we see as a streak of light or falling star.  It's a phenomenon caused by a tiny fleck of cosmic dust that burns up entering Earth's atmosphere.  A meteorite is a solid celestial body that survived it's fall to Earth.  We can hold these in our hands.

     What is a fall and a find?  A fall is a meteorite that was seen streaking through the air and falling to the ground.  Many people only collect falls.  A find is a meteorite that was found and was not seen falling.  

     Meteorite Classification

Stones - Chondrites - with chondrules - carbonaceous, enstatite, olivine-bronzite, olivine-hypersthene and amphoterites.

Stones - Achondrites - without chondrules - angrites, aubrites, ureilites, howardites, eucrites, diogenites, shergottites, nakhlites and chassignite

Stony Irons - lodranites, mesosiderites, pallasites and siderophyre

Irons - hexahedrites, octahedrites and ataxites.

Yearly Meteor Showers

January 3 - 4 Quadrantids
April 21 - 22 Lyrids
May 3 - 5 Eta Aquarids
July 29 - 30 Delta Aquarids
August 11 - 12 Perseids
October 8 - 9 Draconids
October 20 - 21 Orionids
November 7 - 8 Taurids
November 16 - 17 Leonids
December 13 - 14 Geminids
December 22 Ursids

Hourly counts vary from year to year.

 

 

Tektites 

     Unlike meteorites, no one knows where tektites came from or how they ended up on Earth.  All theories have been proven wrong so far.  

     Tektites were shaped by rapid rotation in a low gravity environment before entering our atmosphere.  The heat from entry made them elastic for a short amount of time.  Hypersonic airflow left interesting grooves and lines on the surface.  Rapid cooling froze them into the shapes we see today.  The most common shapes are spheres, dumbbells, discs, teardrops, hollows, boomerangs, ovals and buttons.  

     Tektites are found in 7 places on Earth called strewn fields.  The 7 strewn fields are North America, Ivory Coast, Aouelloul, Czechoslovakian, Irgiz, Libyan Desert and Australasian.  The tektites found in each strewn field have unique markings or shapes associated with that area.  Looking at a map, tektites fell to Earth in an S shape.  Evidently, all at one time.  No one has ever reported seeing a tektite fall.  

     Tektites are not associated with known craters as Impactites are.  Impactites are glass ejecta from known craters.  

     Tektites are extremely dry.  They contain only 100 ppm of water.  Most igneous rocks on Earth contain 5000 ppm of water.  Tektites are 80% silica (Si02) with traces of aluminum, iron, magnesium, calcium, sodium, potassium and titanium.

     Tektites are a highly siliceous glass body of mysterious cosmic origin.     

 

 

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