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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