Solar System Debris and Dwarf Planets

This set of flashcards provides a comprehensive overview of key concepts, facts, and vocabulary relevant to the study of Solar System debris and dwarf planets. They cover topics such as asteroids, comets, impacts, and the definition of dwarf planets.

Asteroid

A small rocky body orbiting the sun, most of which are found in the asteroid belt between Mars and Jupiter.

Asteroid belt

A region of space located between the orbits of Mars and Jupiter, populated by numerous asteroids.

Comet

An icy celestial body that, when passing close to the sun, warms and begins to release gases, forming a visible atmosphere and tail.

Kuiper Belt

A region of the solar system beyond the orbit of Neptune, populated with many small icy bodies and short-period comets.

Oort Cloud

A theoretical cloud of predominantly icy objects surrounding the solar system, thought to be the source of long-period comets.

Dwarf Planet

A celestial body that orbits the sun, has sufficient mass for a nearly round shape, but has not cleared its orbital path.

Meteoroid

A small particle from a comet or asteroid that is smaller than 100 meters in diameter.

Meteor

A meteoroid that enters the Earth's atmosphere and burns up, producing a bright streak of light.

Meteorite

A meteoroid that survives its passage through the Earth's atmosphere and lands on Earth.

Iridium layer

A layer of sediment rich in iridium that is associated with the impact event believed to have contributed to the extinction of the dinosaurs.

Chicxulub Crater

An impact crater located near the Yucatán Peninsula in Mexico, associated with the mass extinction event that killed the dinosaurs.

S-type asteroid

Asteroids composed mainly of silicate minerals.

C-type asteroid

Carbonaceous asteroids, which are the most common type, thought to be the building blocks of the solar system.

Eccentric orbit

An orbit that deviates from a perfect circle, appearing elongated or stretched.

Galileo probe

A NASA spacecraft that explored the asteroids Gaspra and Ida among its missions.

Density

Mass per unit volume, a measure of how compact a substance is.

Apollo asteroids

A group of asteroids that cross Earth's orbit and could potentially pose a collision threat.

Momentum

The quantity of motion an object has, proportional to its mass and velocity.

Impacts

Events where an asteroid or comet collides with another celestial body, often causing significant damage.

Dactyl

A small moon of asteroid 243 Ida, discovered during the Galileo spacecraft mission.

NEAR Shoemaker

A NASA spacecraft that studied and landed on the asteroid Eros.

Global catastrophe

A major environmental disruption that can destroy ecosystems and species on a large scale.

Tunguska event

A large explosion that occurred in Siberia in 1908, believed to have been caused by the airburst of a meteoroid or comet.

Halley's Comet

A well-known periodic comet with a 76-year orbital period, last seen in 1986.

Nucleus (comet)

The solid core of a comet made from ice and rock.

Coma

The nebulous envelope around the nucleus of a comet, formed when it approaches the sun.

Tail (comet)

The ion and dust trail that a comet leaves behind as it approaches the sun.

Cometary tail orientation

Comet tails always point away from the sun due to solar wind.

Stardust mission

A NASA mission that collected samples from the tail of comet Wild 2.

Deep Impact mission

A NASA mission that studied the composition of comet Tempel 1 by impacting it with a projectile.

Philae lander

The lander deployed by the Rosetta spacecraft to study comet 67P/Churyumov–Gerasimenko.

Meteor showers

Events where streams of meteors are observed when Earth passes through the debris left by comets.

Quadrantid meteor shower

A meteor shower that peaks around January 3, originating from the asteroid 18611 Thatcher.

Perseid meteor shower

A prominent meteor shower that occurs in August, associated with comet Swift-Tuttle.

Geminid meteor shower

A meteor shower that occurs every December, associated with asteroid 3200 Phaeton.

Eris

A dwarf planet located in the scattered disc, larger than Pluto and discovered in 2005.

Makemake

A dwarf planet discovered in 2005, named after the creator god of the Rapa Nui people.

Haumea

A dwarf planet recognized for its elongated shape and multiple moons.

New Horizons mission

NASA’s mission that traveled to Pluto, providing unprecedented data about this dwarf planet.

Ceres

The largest object in the asteroid belt and classified as a dwarf planet.

Trans-Neptunian Object (TNO)

Any celestial object located beyond the orbit of Neptune.

Kerberos and Styx

Moons of Pluto, discovered through Hubble Telescope observations.

Clyde Tombaugh

The astronomer who discovered Pluto in 1930.

Percival Lowell

The astronomer who predicted the existence of Pluto in 1916.

NASA

The United States government agency responsible for the nation's civilian space program and for aeronautics and aerospace research.

Gravity

The force that attracts two bodies toward each other, particularly the force that holds planets in orbit.

Planet definition (IAU)

A body that orbits the Sun, is massive enough to be round, and clears its orbital path.

Asteroid classification

Asteroids are categorized as S-type, C-type, and M-type based on their composition.

Impact crater

A depression formed on the surface of a celestial body by the impact of a meteorite.

Solar wind

A stream of charged particles released from the upper atmosphere of the sun.

Nix and Hydra

Small moons of Pluto, discovered in 2005.

Celestial body

Any natural object outside of Earth's atmosphere, including planets, moons, asteroids, comets, etc.

Asteroid density characteristic

Many asteroids have low densities and are not solid.

Outer Kuiper Belt

Region of the Kuiper Belt that lies beyond the traditional boundary of the asteroid belt.

Satellite

A celestial body that orbits a planet, including moons.

Minor planet

A term sometimes used to refer to asteroids and other celestial bodies that orbit the sun but are not classified as planets.

Vesta and Pallas

The two largest asteroids in the asteroid belt.

Ceres (dwarf planet)

Dwarf planet located in the asteroid belt, previously classified as an asteroid.

Sedna

A distant trans-Neptunian object with an orbit that takes it far from the sun.

Quaoar

A large trans-Neptunian object discovered in 2002.

Hydra

One of Pluto's moons, known for its small size.

Spacecraft

A vehicle designed for travel or operation in outer space.

Atmosphere

The envelope of gases surrounding a celestial body.

Solar system formation

The process by which the solar system formed from a large cloud of gas and dust.

Exploration missions

Space missions designed to study celestial bodies outside Earth's orbit.

Interplanetary matter

Material, such as meteoroids, found between the planets.

Discovery of dwarf planets

Pluto was reclassified as a dwarf planet after IAU set a formal definition.

Oort Cloud significance

Believed to be the origin of long-period comets; remains unconfirmed.

Density measurement in space

Important for determining the physical characteristics of celestial bodies.

Telescope

An optical instrument used to observe distant celestial objects.

Finding evidence

Scientists rely on physical evidence, such as impact craters, to understand historical events.

Gravitational effects

Influence of gravity on celestial bodies, affecting their orbits.

Friction and meteors

Meteors produce light from the friction as they enter the atmosphere.

Seismic activity on asteroids

Some asteroids show signs of past volcanic activity.

Transitional bodies between comets and asteroids

Objects such as certain meteoroids, which share characteristics of both.

Eccentricity in orbits

Describes how much an orbit deviates from a perfect circle.

Space debris accumulation

Includes spent rocket stages, dead satellites, and fragments from previous space missions.

Long-period comets

Comets that take more than 200 years to orbit the sun.

Short-period comets

Comets that take less than 200 years to complete an orbit around the sun.

Orbital dynamics

The study of the motions of celestial bodies and how their orbits change.

Bright spots on Ceres

These are reflective areas interpreted as deposits of ice.

Planetary classification impact

Reclassification of Pluto influenced the criteria for defining planets.

Celestial classifications (IAU)

Definitions provided by the International Astronomical Union for classifying celestial bodies.

Spectroscopy

An analytical technique used to identify materials by observing their spectrum.

Planetary missions

Exploration of celestial bodies primarily for gathering scientific data.

Gravitational interaction

The effect between celestial bodies due to their mass and distance.

Planetary science

The study of planets, moons, stars, and other celestial bodies.

Astrobiology

The study of the origin and possibility of life elsewhere in the universe.

Radiometric dating

A technique used to date materials using the decay of radioactive isotopes.

Asteroid composition analysis

Determining the materials that make up an asteroid through various methods.

Chthonian planets

Hypothetical planets that were once gas giants and lost their atmosphere due to close proximity to their star.

Surface exploration

Study of the surface characteristics of celestial bodies.

Fission and fusion processes

Nuclear reactions that release energy, important for understanding stellar systems.

Environmental impact of asteroids

Potential threats posed by asteroid collisions with Earth.

Asteroids' role in solar system evolution

They are considered relics from the formation of the solar system.

Extraterrestrial impacts

Events where objects from space collide with Earth, potentially causing significant changes.

Planetary isolation effect

Conditions under which certain celestial bodies adjust their orbits and physical properties.

Impact event threshold

The energy level required for an impact to cause significant damage.

Astrophysical research

The field that studies the physics and properties of celestial bodies.

Planetary atmospheres

Gases surrounding celestial bodies, essential for sustaining life.