Transcript Meteorites - indstate.edu

Meteorites
This meteorite, a basalt lava rock
nearly indistinguishable from many
Earth rocks, provided the first strong
proof that meteorites could come from
Mars. Originally weighing nearly 8
kilograms (17.6 pounds), it was
collected in 1979 in the Elephant
Moraine area of Antarctica.
This meteorite fell in 1970 in
Cherokee County, Oklahoma. It is
subclassed as H Group or an olivinebronzite chondrite. Meteorites are
bits of rock that are captured by a
planet's gravity and pulled to the
surface. This meteorite is of a type
named chondrite and is thought to
have formed at the same time as the
planets in the solar nebula, about
4.55 billion years ago. (Copyright
Calvin J. Hamilton)
This is a section from a stone
chondrite meteorite that fell in
1852 in Harghita, Romania.
(Copyright Calvin J. Hamilton)
This meteorite fell in 1924.
Notice the depreessions on this
sample. These are called
regmaglypts and are most
likely paralled to the air flow
direction during the flight of the
meteorite. (Copyright Calvin J.
Hamilton)
Discovered at Norton County, Kansas, this type of meteorite is known as an achondrite. It
has a basaltic1 composition and was probably formed when an asteroid melted about 4.5
billion years ago. The asteroid broke up some time later and this small piece of the asteroid
was captured by Earth's gravity and fell to the ground. (Copyright Calvin J. Hamilton)
1A
general term for dark-colored, igneous rocks composed of minerals that are relatively rich in iron and
magnesium.
This iron meteorite was found
at Victoria Land, Antarctica.
This type of meteorite gets its
name because it is mostly
made of the elements iron and
nickel. This sample is probably
a small piece from the core of a
large asteroid that broke apart.
(Copyright Calvin J. Hamilton)
This Iron (III E) Meteorite contains a distinctive crystal pattern known as the Widmanstaten structure. It
was fashioned over thousands or millions of years in a low gravity environment at an extremely low
rate of cooling producing large crystals of nickel-rich and nickel-poor metallic bands. Such a structure
is impossible to forge making the identity of this and similar iron meteorites absolute. Laboratories are
only able to imitate it on the microscopic scale. This sample has been cut, polished and etched with
acid to enhance the view of the Widmanstaten structure. (Copyright Calvin J. Hamilton)
Edmonton - Iron (III CD) Meteorite
This meteorite was found in 1942. (Copyright Calvin J.
Hamilton)
Martian Meteorite
This meteorite fell in 1911 in Alexandria, Egypt. It is believed to have
formed on Mars based on its dense pyroxene (greenish-gray) and
olivine (brown) crystals which are a signature of martian molten rock. It
also contains water-bearing minerals. (Copyright Calvin J. Hamilton)
Martian Meteorite Slice
This meteorite fell in 1962 in
Katsina Province, Nigeria. It
is believed that it is a
fragment of a Martian lava
flow. It found its way to
Earth when a giant impact
on Mars catapulted rock
fragments into space. A
close look at the black glass
veins show they are impact
melt that contain Martian
gases. (Copyright Calvin J.
Hamilton)
Peekskill Meteorite
This meteorite is famous for the fact that when it fell on October 9,
1992 it destroyed the trunk of a car in Westchester County, New
York. (Copyright Calvin J. Hamilton)
Stony-iron Meteorite
This stony-iron, Pallasite meteorite
was found in Atacama, Chile in
1822. (Copyright Calvin J. Hamilton)
Stony-iron Meteorite
This Stony-iron , pallasite
meteorite was found in 1909 in
Chihuahua, Mexico. (Copyright
Calvin J. Hamilton)
Vesta Meteorite
This meteorite is assumed to be a sample of the crust of the asteroid Vesta, which is only the third solar
system object beyond Earth where scientists have a laboratory sample (the other extraterrestrial samples are
from Mars and the Moon). The meteorite is unique because it is made almost entirely of the mineral pyroxene,
common in lava flows. The meteorite's mineral grain structure also indicates it was once molten, and its
oxygen isotopes are unlike oxygen isotopes found for all other rocks of the Earth and Moon. The meteorite's
chemical identity points to the asteroid Vesta because it has the same unique spectral signature of the mineral
pyroxene. Most of the identified meteorites from Vesta are in the care of the Western Australian Museum. This
1.4 pound (631 gm) specimen comes from the New England Meteoritical Services. It is a complete specimen
measuring 9.6 x 8.1 x 8.7 centimeters (3.7 x 3.1 x 3.4 inches), showing the fusion crust, evidence of the last
stage in its journey to Earth. (Photo Credit: R. Kempton, New England Meteoritical Services)