Most meteorites that fall on Earth are fragments of broken-up asteroids which orbit the Sun mostly between the orbits of Mars and Jupiter. This is indicated by photography of meteorite fire balls as they enter Earth

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Most meteorites that fall on Earth are fragments
of broken-up asteroids which orbit the Sun mostly
between the orbits of Mars and Jupiter. This is
indicated by photography of meteorite fire balls
as they enter Earths atmosphere, and
extrapolation of the orbits which reach into the
Asteroid Belt.
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Photograph of the bolide resulting from the entry
of the Lost City, Oklahoma, stone meteorite
(ordinary chondrite) on January 3, 1970.
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The Lost City, Oklahoma, stone meteorite,
recovered based on the triangulation of the place
of fall from the photographs of the associated
bolide
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Telescopically measured optical reflectance
spectra of asteroids (points, with error bars)
with the spectra of powders of various types of
meteorites (solid lines). Conclusion The
meteorite spectra match the asteroid spectra and,
hence, the meteorites come from asteroids
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A Comet Toit-Hartley B Asteroid 1982 DB
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The Galileo spacecraft, on its way to Jupiter,
was the first to obtain close-up pictures of
asteroids
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The complex orbit of the Galileo spacecraft
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The Galileo spacecraft during construction
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Launch of the Galileo spacecraft from the Shuttle
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Galileo Spacecraft after launch from the Shuttle
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The Galileo spacecraft imaged the asteroids
Gaspra and Ida. Mathilde was imaged by the NEAR
spacecraft.
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Asteroids are highly irregular in shape, and some
may have moons too! Ida and its moon Dactyl,
imaged by the Galileo spacecraft
Dactyl
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Asteroid Mathilde, imaged by the NEAR Spacecraft
on its way to Asteroid Eros
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Asteroid Eros Orbited by NEAR spacecraft in
2000
NEAR Near Earth Asteroid Rendezvous mission
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Asteroid Eros and landing site of NEAR Spacecraft
Landing site
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NEAR Spacecraft approaching Asteroid Eros
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NEAR Spacecraft approaches the landing site on
Asteroid Eros
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Landing site of the NEAR Spacecraft on Asteroid
Eros, February 12th, 2001
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Topography of Asteroid Eros, based on the NEAR
mission
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How many asteroids are there and where are they?
Number of asteroids as a function of their
distance from the Sun (in AU). The Kirkwood Gaps
are apparent, and the resonances with Jupiter are
also indicated
Inclination of orbits of asteroids as a function
of distance from the Sun (in AU)
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Orbits of some major asteroids
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Summary
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Chondrites are meteorites from broken-up
primitive, undifferentiated asteroids that never
melted. Thus, the properties of their
constituents calcium-aluminum-rich inclusions
(CAIs), chondrules, matrix, and metallic Fe,Ni
are today as they were when the Solar System
formed

Chondrite NWA 5028
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Polished slice of an ordinary chondrite. White
metallic Fe,Ni brown silicates.
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Handspecimen of an ordinary chondrite with a
large chondrule
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Thin section photomicrograph of an ordinary
chondrite. Chondrules are 1 - 5 mm in diameter
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Chondrule consisting of glass (pink) and olivine
(Fe-Mg- silicate) crystals (white)
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Barred chondrule consisting of parallel bars of
olivine (Fe-Mg silicate) crystals (white) and
silicate glass (pink-brown)
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When a chondritic asteroid melts, it
differentiates, i.e., the dense metallic Fe,Ni
sinks and forms the core, and the rocky material
forms the mantel (e.g., ureilite) and crust
(e.g., basalt) of the asteroid. These rocks are
collectively called achondrites, because they do
not contain chondrules.
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Minute diamonds (bright) in a ureilite. They
formed from carbon by high-pressure shock when
asteroids collided.
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Basaltic meteorite (eucrite), most likely from
the crust of the asteroid Vesta
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Pallasite possibly fragment from the
core/mantle boundary of a broken-up
asteroid. Shiny metallic Fe,Ni brown
olivine, an Fe-Mg-silicate.
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When a chondritic asteroid melts, it
differentiates, i.e., the dense metallic Fe,Ni
sinks and forms the core, and the rocky material
forms the mantel (e.g., ureilite) and crust
(e.g., basalt) of the asteroid (just like in
case of Earth).
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Handspecimen of an iron meteorite a fragment of
the core of a broken-up asteroid
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How many meteorites, and of what types? Early
observations of Falls and Finds, excluding
those from Antarctica and hot deserts.
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