Astronomy & Geology Final Exam Study Guide Flashcards

Flashcards based on the PHSC 4402 Astronomy & Geology study guide for the final exam, Spring 2025.

Geology

The study of the Earth, its constituent materials, the arrangement of these materials (structure), and the processes acting upon them. It includes the study of organisms that inhabit our planet and how all these aspects change over time.

Earth Science

The comprehensive study of the Earth System, which encompasses all its interacting components (atmosphere, hydrosphere, cryosphere, geosphere, and biosphere) and their interrelationships. It seeks to understand how these components function together to create the Earth environment.

Rocks

Naturally formed aggregates comprised of two or more minerals.

The specific mineral composition and the manner in which they are assembled dictate the rock's characteristics and classification.

Mineral

A naturally occurring, inorganic solid with a definite chemical composition and a crystalline structure. These unique chemical and physical properties arise from its internal arrangement of atoms.

Igneous Rock

formed from cooling and crystallization of magma or lava

Sedimentary Rock

formed from preexisting rocks subjected to weathering and erosion

Metamorphic Rock

formed from either igneous, sedimentary, or other metamorphic rock when the physical nature of the rock is altered by heat, chemical, pressure, or other agent

Weathering

the physical breakdown and chemical alteration of rock at Earth’s surface. There are two types of weathering: chemical and mechanical

Erosion

The physical removal of material by mobile agents such as water, wind, ice, or gravity.

Erosion does not occur in place. It involves movement and results from existing rock transformed by heat, pressure, or chemical fluids.

Magma

Molten rock material from which minerals can crystallize

Lava

Magma, when it makes it to, and flows on the surface

External Processes

Geological processes that occur at or near the Earth's surface, driven primarily by solar energy and gravity.

These processes include

• weathering

• mass wasting (slope failure),

• erosion, shaping the landscape over various timescales.

Internal Processes

Geological processes driven by Earth's internal heat which is received by the earth surface

including

• volcanism (eruption of molten rock)

• plate tectonics (movement of Earth's lithospheric plates)

  • These processes build mountains, create ocean basins, and cause earthquakes.

4 major Earth's Interior Zones

• (1) crust (the very thin outer layer),

• (2) mantle (a rocky layer located below the crust),

• (3) outer core (a layer which exhibits the characteristics of a mobile liquid), and

• (4) inner core (a solid metallic sphere).

Theory of Plate Tectonics

states that Earth's lithosphere (the crust and upper mantle) is divided into segments called plates that are in motion relative to each other.

Most of Earth's seismic activity, volcanism, and mountain building occur along the dynamic margins of these plates

Divergent Plate Boundaries

occur where plates move apart, resulting in upwelling of material from the mantle to create new seafloor.

Convergent Plate Boundaries

occur where plates move together, resulting in the subduction of oceanic lithosphere into the mantle along a deep oceanic trench

Transform Fault Boundaries

where plates grind past each other without the production or destruction of lithosphere.

What is the relation between energy and wavelength

The energy difference corresponds to a specific wavelength of light (or more generally, electromagnetic or EM radiation); shorter wavelengths correspond to higher energy, while longer wavelengths correspond to lower energy.

Each atom or element has a specific set of energy levels, which result in each having a unique spectral “fingerprint.”

Spectral Lines

Unique patterns of dark or bright lines in a spectrum of light emitted or absorbed by a substance. Each atom or element possesses a specific set of energy levels, resulting in a unique spectral “fingerprint” that allows for its identification.

Optical Reflecting Telescopes

Telescopes that utilize large, curved mirrors to collect and focus light from celestial objects. The size of the mirror determines the telescope's light-gathering power and ability to resolve fine details.

Seeing

• limit on resolution due to the atmosphere.

• Space-based telescopes do not have this problem.

Adaptive Optics can help correct the distortion of seeing, how

help correct for this distortion, giving Earth-based image quality can compete with the Hubble Space Telescope in the visible part of the atmosphere.

Charge-Coupled Devices (CCDs)

are electronic detectors that record photons as electronic counts. The electronically recorded images can greatly exceed photographs in quality.

Spectrographs

disperse the incoming light into its component wavelengths and let astronomers study the spectra of objects’ light.

Radio Telescopes

large, steerable parabolic dishes with antennas that allow astronomers to study radio waves.

Satellites

detect wavelengths that the atmosphere blocks (ultraviolet and X-rays)

similaries between the moon and mercury

• Both most totally airless

• no liquid water.

• A combination of temperatures

• low escape velocity means any atmosphere is lost.

• No erosion from wind or other weathering, so old, cratered surfaces are retained.

• Impacts play the dominant role in resurfacing both planets.

the number of craters indicates what

a surfaces age

There is a strong evidence for ice in permanetly shadowed craters at the lunar poles, how is this made possible

the paremanet shadows are made possible by the moon’s 1.54 degree tilt

The planet with the largest number of volcanoes in the solar system is _, although most are currently inactive.

Venus

Greenhouse Gasses

• Incoming sunlight heats the planet, Outgoing infrared radiation cools the planet

• Co2 and water block infrared radation preventing the planet from cooling

• This greenhouse effect means the planet is at a higher temperature due to the extra energy needed to be in equilibrium with the sunlight.

Earth's Atmosphere Components

The two most abundant gases in Earth's atmosphere are and , which together comprise approximately 99% of the dry atmosphere.

Venus's Atmosphere

Mars's Atmosphere

The atmosphere of _ is cold and thin, resulting in extreme temperature variations between day and night. The planet's low atmospheric density and lack of a substantial ozone layer also make it vulnerable to solar radiation.

What are the 4 giant planets and where are they located

• Jupiter, Saturn, Uranus and Neptune

• Located beyond the Asteroid Belt, between 5AU and 30AU,

What is the largest satellites and what does it orbit

• Ganymede which orbits Jupiter

• Titan which orbits Saturn

  • both are larger than mecury

Io

_ is the most volcanically active world in the Solar System

Comet

A small, icy body that, when heated by the sun, sublimates (transitions directly from solid to gas). This creates a visible atmosphere called a coma, and often one or two tails: an tail (composed of ionized gas) and sometimes a tail (composed of dust particles).

Meteor Showers

Occurrences take place when Earth passes through the debris trails left by comets. The dust particles collide with Earth’s atmosphere, they heat up and disintegrate, resulting in “shooting stars” (or meteors).

How extra-solar planets are discovered

Extra-solar planets are discovered via radial velocity measurements, by astrometry (watching the wobble), direct/primary transit observation and direct imaging

Super-Earths

• Planets whose masses range from 1.1 to 10 Earth masses

• is what the new worlds are called

• believed to be 600

what are the 3 types of heat transfer

conductive, convective and radaition with the most important being the bolded ones

Features of the Sun's atmosphere

The Sun's atmosphere consists of several layers. The displays sunspots and limb darkening. The shows filaments, prominences, and plages. The _ exhibits coronal streamers and coronal mass ejections.

Apparent Magnitude

The brightness of a star when viewed from Earth, without correcting for its distance. It is influenced by both the star's intrinsic luminosity and its distance from Earth.

Absolute Magnitude

The apparent magnitude a star would have if it were located at a standard distance of 10 parsecs (32.6 light-years) from Earth. It provides a measure of the star's intrinsic luminosity, independent of its distance.

Main-sequence stars

Stars that are fusing hydrogen into helium in their cores. They represent the majority of stars in the universe-- about _ percent of them.

Luminosity or brightness of a star

The most important factors that determine the luminosity or brightness of a star is the and of the star.

Evolutionary Steps for a Sun-like Star

A star with a mass similar to our Sun progresses through the following stages: , , , , and finally _.

Means by which to estimate distances to stars and galaxies

Distances to stars and galaxies can be estimated using the following methods: , , , and .

Types of Galaxies

The three main types of galaxies observed in the universe are , , and _.

Hubble's Law

The observation that galaxies are receding from us at a speed proportional to their distance. This relationship provides strong evidence for the expansion of the universe.

Big Bang Theory

The prevailing cosmological model for the universe, which proposes that at one time the entire universe was confined to a dense, hot, supermassive concentration. It has been expanding and cooling ever since.

What are the 3 types of rock

igneous metamorphic and sedimentary

the single most important agent that sculpts the Earth’s surface ___________ but ______ and glaciersalso plays a minor role

running water / glaciers and erosion

Most earthquakes originate where

along plate boundaries

how do earthquakes start?

result from the rapid release of energy from rocks that rupture due to being subjected to stresses beyond their limits.

Where are volcanoes located

Along oceanic ridges / seafloor spreading.

Near ocean trenches / one plate subducted by another plate

In the interior of plates, mostly due to rising plumes of hot mantle rock

What are mountains made of

consist of roughly parallel ridges of folded and faulted sedimentary

volcanic rocks, portions of which have been strongly metamorphosed and intruded by younger igneous bodies.

As they are heated from low to high temperature, solid objects will appear to glow in the following sequences of , ___ ________ ______

red, yellow and white

what 4 facts do we use to study about the universe

(1) the state of matter of an object (solid, liquid, high- or low-pressure gas;

(2) the composition of gaseous objects;

(3) the temperature of a radiating body; and

(4) the motion of an object.

The volcanoes on this planet are the largest mountains in the Solar system and are what type of volcanoes

Mars , shield volcanoes

Differences between Earth, Venus and Mars

	Earth		Venus		Mars
Volcanoes			Venus has the largest number of volcanoes in the Solar System		The volcanoes on Mars are the largest mountains in the Solar System and are shield volcanoes.
Erosion	wind and water strongly erode features		Wind also modifies the surfaces		Wind also modifies the surfaces
Atmosphere	Mostly nitrogen and oxygen. Life is responsible for the oxygen in Earth’s atmosphere. Ozone blocks ultraviolet light, which is harmful		Hot, dense mainly CO2, atmosphere, completely cloud covered, strong greenhouse effect sends surface temperature to 737 K (860°F). Surface pressure is 92 times that on Earth. Thick atmosphere means nearly uniform temperatures over the entire planet. Rotates on its axis very slowly, and in the opposite direction.		Cold, thin atmosphere = extreme temperature variations. Even with carbon dioxide, the greenhouse effect is very limited.

What are the 2 groups for giant planets

gas giants and ice giants

what do all giant planets have

• ring system

• strong magnetic field that is generated internally

• many Satellites

• orbits far from the sun

• many moons

• fast rotators

• cold

• long years

• large

• Atmosphere includes lighter atoms (H, He)

• have no solid surface, gas is just thicker

• has dnymaic storms

The Ring system on Giant planets…

• thought to form from breakup of the moon or raw materials blasted off an exisiting moon by meteor impacts

What planet has the most spectaular rings

• Saturn

• All the structures observed in Saturn’s ring system are the result of gravitational interactions between moons and rings.

How where Jupiters rings formed and sustained

dust blasted from the inner moon

Do Rings last forever

No, the material, through collisions with other material particles, the rings lose material through particles moving toward the outer edge of the rings and drifting away or moving to the inner edge and eventually spiraling into their host planet.

What is the only exception with rings lasting forever

Shephered moons of Saturn, Uranus and Neptune keep objects from escaping

What causes gaps in rings and can influence overall chemical content

Orbital

How many other

• planetary systems

• Worlds

• and how many have more than one planet

• 5,039

• 7347

• 1021

How can we find planetary systems

• The first is via radial velocity measurements.

• The second is by astrometry, that is, watching the wobble of the center of mass of the system as shown by the visible star.

• The third and most successful is direct / primary transit observation.

• The fourth is direct imaging

• We can also infer the presence of a planet through interactions with a dust cloud that surrounds the system.

What are the the 3 layers of the Sun’s atmosphere and what do they display

The Photosphere displays sunspots and limb darkening.

o The chromosphere shows filaments, prominences, and plages.

o The corona exhibits coronal streamers and coronal mass ejections.

Apparent magnitude (refering to stars)

is the brightness of a star when viewed from Earth regardless of distance

absolute magnitude (refering to the stars)

is the apparent magnitude the star would have at 10 parsecs (= 32.6 light years).

what is the differences between stars apparent and absolute magnitude

the stars distance

On an H-R diagram, about 90 percent of the stars are what kind of stars

main sequence stars

Do Stars with equal surface temperatures radiate the same amount of energy per unit area?

yes

luminosity/ brightness of star depends on what

• mass and size

How do stable stars balance the inward force of gravity

with gas pressure from thermal expansion.

The center of mass of orbiting binary stars (two stars revolving around a common center of mass under their mutual gravitational attraction) is used to determine what?

mass of the individual stars in a binary system

Hertzsprung-Russell diagram

• is constructed by plotting the absolute magnitudes and temperatures of stars on a graph. This graph can also use luminosities versus spectral type, and energy output per unit area versus color. • The correct sequence of evolutionary steps for a Sun-like star, from start to finishis proto-star, main sequence, red giant, planetary nebula, and white dwarf.

what are some ways astronmers measure stars distance

• they are trigonometric parallax (or triangulation to the nearest stars)

• distance modulus / “main sequence fitting” / spectroscopic parallax,

• Cepheid variables

• Type I supernova.

The milky way

appears to be densely surrounded by stars because our solar system is located within the flat galactic disk.

What are other types of galaxies

• irregular galaxies, which lack symmetry and account for only 10 percent of the known galaxies.

• (2) spiral galaxies, which are typically disk-shaped with a somewhat greater concentration of stars near their centers, often containing arms of stars extending from their central nucleus; and

• (3) elliptical galaxies, the most abundant type, have an ellipsoidal shape that ranges to nearly spherical and that lack spiral arms.

What is the most observed galaxy in the universe

elliptical

Hubbles law

states that galaxies are receding from us at a speed proportional to their distance.

Big bang theory

the origin of the universe is based on the premise that at one time the entire universe was at one time confined to a dense, hot, supermassive concentration.

• Almost 14 billion years ago, a cataclysmic explosion hurled this material in all directions, creating all matter and space.

• Eventually the ejected masses of gas cooled and condensed, forming the stellar systems we now observe fleeing from their place of origin.