AST_190_AsteroidsComets_10_9.pdf

Asteroids

Rocky (and some metallic) irregular shaped objects that orbit the Sun.

Asteroid Belt

Main region where most asteroids are found, situated between the orbits of Mars and Jupiter.

Near-Earth Objects (NEOs)

Asteroids whose orbits bring them close to Earth's orbit.

Trojan Asteroids

Asteroids that share orbit with a larger planet, remaining in stable regions ahead of and behind the planet.

Kirkwood Gaps

Regions in the asteroid belt with very few asteroids due to orbital resonance with Jupiter.

Dust Tail

Made up of small solid particles pushed away from the nucleus by the pressure of sunlight, appears white or yellow.

Coma

Bright cloud of gas and dust that surrounds the nucleus of a comet when heated by the Sun.

DART (Double Asteroid Redirection Test)

Spacecraft test aimed at altering an asteroid's trajectory by crashing into it.

Ceres

Largest asteroid in the asteroid belt, classified as a dwarf planet, with a diameter of 940 km.

NEAR Earth Asteroids

Subset of asteroids whose orbits bring them close to Earth; includes Amor, Apollo, Aten, and Atira classifications.

Spectroscopy

Technique used to study the composition and surface properties of asteroids.

C Type Asteroids

Dark, carbon-rich asteroids with albedo approximately 5%.

Short-period comets

Comets with orbital periods less than 200 years, typically having low inclination angles.

Oort Cloud

A spherical region surrounding the solar system, where long-period comets originate.

Ion Tail

Ionized gas tail of a comet blown away from the nucleus by solar wind; appears blue due to emission of light.

Eros

A near-Earth S-type asteroid visited by NASA's NEAR Shoemaker mission.

Comet Dust Trail

Stream of dust and gas particles left in a comet's orbit that can cause meteor showers when Earth passes through it.

C/2023 A3

A comet designation that reflects its discovery time under the International Astronomical Union nomenclature.

Cryovolcanism

Volcanic activity involving the eruption of icy materials instead of molten rock, found in bodies like Ceres.

Psyche Mission

NASA mission planned to explore the metallic asteroid 16 Psyche.

C/2024 S1

Another designation for a comet, indicating the year of its discovery.

Planetary Defense

Strategies and techniques developed to protect Earth from potential asteroid impacts.

Rhิ่งgtélater

When a comet passes near the Sun, causing sublimation of ice and formation of a tail.

Albedo

A parameter reflecting the reflectivity of a celestial object, important in classifying asteroids.