Impulse (change in velocity) required to accomplish a specific manuever in space


Internal stratification of a body, caused by heating and usually resulting in a core, mantle, and crust


The plane defined by Earth's orbit around the Sun

Electromagnetic induction heating

Method proposed for asteroid heating, using electric currents induced by variations in a strong solar wind

Emission band

Radiation emitted by an object at a particular range of wavelengths

Interplanetary dust particles

Tiny particles that once orbited in the spaces between planets, normally collected in the stratosphere by high-flying aircraft

Iron meteorite

One composed primarily of iron-nickel alloy



Isotope produced by exposure to cosmic rays


Unstable isotope that decays spontaneously


Isotope formed by radioactive decay

Kuiper Belt

Zone of presumably icy planetesimals located outside the orbit of Neptune

Light curve

Variations in amplitude observed as an asteroid rotates

Metamorphic grade

Relative intensity of heating and recrystallization


Two points at which an object's orbit intersects Earth's orbital plane

Oort Cloud

Spherical halo of icy planetesimals located between approximately 1,000 and 50,000 AU from the Sun

Orbital precession

Slow, periodic rotation of the long axis of an orbit

Parent body

Object of asteroidal size from which meteorites were derived


Study of the mineralogy, texture, structures, and origin of rocks


Measurement of light intensities


Silicate mineral with layered crystal structure


Rocks that crystallized from magma at depth


See Isotopes


See Isotopes

Radiometric dating

Determining the age of a sample from measurement of its radionuclides

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