| Find
a Meteorite: Explore Meteorites |
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A chondrule, a
crystallized sphere of rocky material found in
chondrites, essentially a tiny igneous rock. |
Asteroids that did not completely melt are thought
to consist of material that formed in the cloud
of dust and gas from which the Solar System formed
called the solar nebula. The stony meteorites
from these bodies are called chondrites,
pronounced “kondrites”. Most chondrites
contain chondrules,
which are small, spherical silicate objects on
the order of a millimeter or less in size. The
chondrules themselves were formed in the nebula
before incorporation into the asteroid by a rapid
heating process, possibly lightning, or other
processes. These meteorites also contain small
amounts of fine-grained iron-nickel metal. Scientists
are interested in chondrites because their chemical
composition reflects that of the solar nebula.
The solar nebula is the cloud of gas and dust
that condensed and accumulated to form the sun
and the planets. We do not know if any of the
chondrite meteorites in our collections actually
come from Ceres, although the spectra of Ceres
is somewhat like carbonaceous chondrites, which
are composed of carbon.”
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| The Kendleton L4 ordinary chondrite. |
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The Leoville carbonaceous chondrite
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The chondrites do not all
represent pristine samples from their formation
in the solar nebula. Some chondrites have been
affected by heat, producing metamorphism, and
the presence of liquid water resulting in alteration
to form clays and other minerals.
The asteroid Ceres may
contain unmelted chondritic material near the
surface and provide clues to the origin of the
Solar System. We do not know if any of the chondrite
meteorites in our collections actually come from
Ceres, although the spectra of Ceres is somewhat
like carbonaceous chondrites. Although the surface
of Ceres appears to be chondritic, there is evidence
that the chondritic material in the upper crust of Ceres may have been altered by water.
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