Planetary Geology and Space Exploration

Vocabulary flashcards covering planetary geology, Martian history and survival, exoplanet classifications, atmospheric effects, and space exploration technologies.

Planetary geology

The study of the surface features of planets and moons.

Craters

Circular depressions formed when meteoroids, asteroids, or comets crash into a planet’s surface at high speed.

Crater Density Age Rule

A geological principle stating that more craters indicate an older surface, while fewer craters indicate a younger surface.

Volcanoes

Features formed when magma rises from inside a planet and erupts, building mountains, creating lava plains, or covering older craters.

Faults

Cracks in a planet’s crust caused by tectonic activity when parts of the crust move apart, together, or slide past each other.

Mars Atmosphere Thickness

The atmosphere of Mars, which is only about $1\%$ as thick as Earth’s.

Mars Average Temperature

The mean temperature on Mars, which is about $-63^{\circ}\text{C}$.

Dynamo

The process by which a planet’s magnetic field is generated by the movement of molten metal inside its core.

Solar wind

A stream of charged particles flowing from the Sun that can strip away a planet's atmosphere if a magnetic field is not present.

Rounded Pebbles

Rocks shaped by flowing water for long periods; found on Mars as evidence of ancient rivers.

Hematite “Blueberries”

Small hematite spheres found by Mars rovers that provide strong evidence that liquid water existed on the planet in the past.

Exoplanet

A planet that orbits a star outside our Solar System.

Hot Jupiters

Exoplanets similar in size to Jupiter that orbit very close to their stars and are extremely hot.

Super-Earths

Exoplanets that are larger than Earth but smaller than Neptune.

Ice Giants

Large planets, such as Uranus and Neptune, that contain large amounts of water, methane, and ammonia ices.

Greenhouse effect

A process where gases such as $CO_2$, methane, and water vapour trap heat to keep a planet's surface warm.

Runaway greenhouse effect

A state where heat becomes trapped faster than it can escape, causing continuous heating, as seen on Venus where surface temperatures reach about $465^{\circ}\text{C}$.

Orbiters

Spacecraft that orbit a planet without landing to map surfaces, study atmospheres, and take photographs.

Rovers

Robotic vehicles that land and move around a planet to explore locations, drill rocks, and analyse soil.

CDSCC

The Canberra Deep Space Communication Complex, located in Australia, which tracks spacecraft and receives data as part of NASA's Deep Space Network.

Line of sight

A clear path required between an antenna and a spacecraft for direct signal communication.

Kessler Syndrome

A chain reaction in Earth's orbit where satellite collisions create debris that leads to further collisions, potentially making orbits unusable.

Transit method

A method to discover exoplanets by detecting tiny dips in a star's brightness when a planet passes in front of it.

James Webb Space Telescope (JWST)

A telescope using infrared light to study distant galaxies and examine chemical compositions of exoplanet atmospheres.

Enceladus

A moon of Saturn featuring water plumes containing salts and organic molecules that shoot into space.

Europa

A moon of Jupiter believed to have an ocean beneath a thick ice crust.