Asteroids

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Asteroid Noun

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[as-tuh-roid]

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Asteroid

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A small, irregular-shaped body of rock and metal that orbits the Sun, often referred to as a minor planet.

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Example: This diagram shows the Main Asteroid Belt, a large ring of rocky objects called asteroids, located in orbit around the Sun between Mars and Jupiter.

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Minor Planet Noun

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[my-ner plan-it]

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Minor Planet

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An alternative name for an asteroid or any celestial body orbiting the Sun that is not a planet or comet.

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Example: This image shows five examples of minor planets, including Ceres, Pluto, and Eris, which are celestial bodies that orbit the Sun but are not planets.

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Planetoid Noun

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[plan-i-toid]

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Planetoid

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Another term for an asteroid, meaning 'planet-like,' used to describe small celestial bodies that orbit the Sun.

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Example: This map shows planetoids, which are small rocky bodies orbiting the Sun, primarily located in the asteroid belt between Mars and Jupiter.

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Orbit Noun

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[or-bit]

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Orbit

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The curved path of a celestial object around a star, planet, or moon, caused by the influence of gravity.

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Example: This diagram shows that an orbit is the curved path, shown by the dotted lines, that objects like planets and asteroids take around a larger object like the Sun.

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Silica Noun

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[sil-i-kuh]

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Silica

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A chemical compound, silicon dioxide, which is a primary component of many rocks and minerals found in asteroids.

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Example: This image shows small, clear beads of silica gel, a manufactured form of silica often used to absorb moisture.

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Silicates Noun

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[sil-i-keyts]

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Silicates

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A large class of important rock-forming minerals that are major constituents of most asteroids, such as olivine and pyroxene.

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Example: This image shows the mineral olivine, a common type of silicate. Silicates are the primary minerals that make up the rocky material of asteroids.

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Olivine Noun

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[ol-i-veen]

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Olivine

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A magnesium iron silicate mineral that is a common type of silicate found in many asteroids and other celestial bodies.

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Example: This image shows a slice of a pallasite meteorite, revealing the yellowish-green olivine crystals embedded within its iron-nickel matrix from an asteroid's core.

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Pyroxene Noun

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[py-rok-seen]

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Pyroxene

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A group of significant rock-forming silicate minerals that are commonly found in the composition of many asteroids.

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Example: This image shows a piece of a rock, likely from an asteroid, that is made mostly of the mineral pyroxene, identifiable by its greenish, crystalline appearance.

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Organic compounds Noun

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[or-gan-ik kom-pounds]

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Organic compounds

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A large class of chemical compounds containing carbon, considered the building blocks of life, found within some asteroids.

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Example: This diagram shows a glucose molecule, an organic compound made of carbon, hydrogen, and oxygen. Similar complex organic compounds have been found on asteroids.

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Asteroid belt Noun

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[as-tuh-roid belt]

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Asteroid belt

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The region of the solar system located between the orbits of Mars and Jupiter where the majority of asteroids reside.

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Example: This diagram shows the main asteroid belt, a region of rocky bodies, orbiting the Sun between the planets Mars and Jupiter.