Astronomy - Quiz 2

Layers of the Earth

1. Crust

2. Mantle

3. Inner Core

4. Outer Core

Crust

• Thinnest layer

• Two types of crust: oceanic and continental

• Oceanic crust: bottom of oceans, dense rocks

• Continental crust: thicker and on land

Mantle

• Thickest layer

• More or less solid

• State of constant motion with hot material upwelling towards the surface and cooler material going deeper

Core

• Densest layer

• Inner core: solid

• Outer core: liquid

Plate Tectonics

Explains how major landforms are created as a result of Earth’s subterranean movements

How do earthquakes occur?

Two tectonic plates slide parallel to each other

How are mountains formed?

Continental masses collide and push against each other

How are volcanoes formed?

• Occurs at the subduction zones where an oceanic plate moves slowly under another

• As the rocks slowly melt, they become a thick flowing substance called magma

• Magma rises and collects in the chamber

• Some of the magma forces its way up to the surface and erupts

Layers of the atmosphere

1. Troposphere

2. Stratosphere

3. Mesosphere

4. Ionosphere

Troposphere

• Closest to the Earth’s surface

• Contains the majority of the mass of the atmosphere

• Layer where clouds are formed and airplanes can fly

Stratosphere

Contains the Ozone layer

Mesosphere

Layer in which meteorites burn

Ionosphere

Has high concentrations of free electrons and ions

Stages of Terrestrial Planets

1. Differentiation

2. Cooling

3. Cratering

4. Magma flooding

5. Weathering

Differentiation

A process where heaver elements sink to the center and lighter remain at the surface

Cooling

A process where the planet’s internal heat flows up to the surface and escapes into space

Cratering

A process where the surface of the planet is bombarded by asteroids and comets

Magma flooding

A process where smooth lowlands are created by magma filling craters by volcanic eruptions

Weathering

A slow process where the flow of atmospheric gas, condensation, and evaporation shape the surface of the planet (only occurs on a planet that has an atmosphere)

What are two ways of determining the age of the planet’s surface?

1. By counting the impact craters

2. By radioactive decay

Planets of the solar system

Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune

What are the differences between the terrestrial planets and Jovian planets?

• Terrestrial planets have shorter orbits, slower spin, no rings, and they are made of rocks and metals

• Jovian planets have longer orbits, faster spin, numerous moons and rings, and are composed of gases and liquids

Mercury

• No atmosphere

• Most elliptical orbit

• No moon

• Smallest and fastest planet

Venus

• Hottest planet

• Extremely thick atmosphere

• Most circular orbit

• No moon

Earth

• Only planet with oceans of liquid water

• Densest planet

Mars

• Home to largest volcano

• Red soil due to iron-oxidizing

• Thin atmosphere

Jupiter

• Largest planet

• Four moons: Callisto, Ganymede, Europa, Io

Saturn

• Known for its ring system

• Least dense planet

• Titan is the largest moon that has an atmosphere

Uranus

• Coldest planet

• Rolls on its axis

• Two sets of rings

Neptune

• Has supersonic winds

• Has a storm called the Dark Spot

Why is Pluto not a planet?

It is not big enough for its gravity to clear away any objects of similar size near its orbit

Galilean Satellites

1. Callisto

2. Ganymede

3. Europa

4. Io

Callisto

• Outer moon

• Frozen before differentiation

• Lacks a dense core

Ganymede

• Largest moon in our solar system

• Evidence of tectonic and volcanic forces

Europa

• Layer of liquid water ocean

• Ice-covered surface

• Geologically active

Io

• Inner moon

• Highest level of volcanism

• Same size as our Moon

Asteroids vs. Comets

• Asteroids: rocky, mostly found in a region between Mars and Jupiter, shorter orbti

• Comets: composed of ice and dust, have a longer orbit, found further out in the solar system

Greenhouse Effect

• The process through which heat is trapped near the Earth’s surface by substances known as greenhouse gases

• The primary gas responsible is carbon dioxide

• Carbon dioxide acts like a blanket and traps heat, which then heats up the surface

Moon Exploration

• NASA is short for National Aeronautics and Space Administration

• Neil Armstrong was the first human to step on the Moon

• The mission, Apollo 11, was launched on July 16, 1969

• The name of the current Moon mission is Artemis