4-C Earth and Space Science

Earth

Earth is the third planet from the sun. Earth is the densest planet in the solar system, the largest of the solar system's four terrestrial planets, and the only astronomical object known to harbor life.

The sun

The Sun is the star at the center of the solar system. It is the most important source of energy for life on Earth.

The moon

The Moon is Earth's only natural satellite. The moon is thought to have formed approximately 4.5 billion years ago, not long after Earth.

Earth's tilt

Seasons are a result of Earth's tilt on its axis. When Earth is tilted toward the sun, it is warmer (summer). When Earth is tilted away from the sun, it is colder (winter). During spring and fall, Earth is tilted on its side. See diagram below.

Fall - Autumn Equinox

Date in the fall when Earth experiences 12 hours of daylight and 12 hours of darkness. This occurs around September 23.

Summer - Solstice

Earth's maximum tilt is toward the sun, causing the longest period of daylight. This occurs around June 22.

Spring - Vernal Equinox

Date in the spring when Earth experiences 12 hours of daylight and 12 hours of darkness. This occurs around March 21.

Winter - Solstice

The North Pole is tilted furthest away from the sun, causing the shortest period of daylight. This occurs around December 21.

Heliocentric and geocentric

The Scientific Revolution began as the Renaissance was coming to an end. The Scientific Revolution marked the emergence of modern science and the heliocentric model regarding the universe.

The heliocentric theory, introduced by Nicolaus Copernicus, positioned the sun at the center of the universe. Copernicus also asserted Earth rotates on its axis while revolving around the sun. Up until that point, it was believed Earth sat stationary at the center of the universe (the geocentric theory). In his book, On the Revolutions of Heavenly Spheres, Copernicus' heliocentric model replaced the geocentric model.

The Moon

The moon affects the tides. When the part of the moon that is illuminated is increasing, the moon phase is waxing. When the part of the moon that is illuminated is decreasing, the moon phase is waning. A waxing moon is illuminated on the right side; a waning moon is illuminated on the left side.

Stars

A star is a luminous ball of gas, mostly hydrogen and helium, held together by its own gravity. A star's color relies on its temperature—hotter stars emit bluer light, and cooler stars emit redder light (Temming 2014).

O

Blue

Over 25,000 Kelvin

B

Blue

11,000-20,000 Kelvin

A

Blue

7,500-11,000 Kelvin

F

Blue to White

6,000-7,500 Kelvin

G

White to Yellow

5,000-6,000 Kelvin

K

Orange to Red

3,500-5,000 Kelvin

M

Red

Under 3,500 Kelvin

Lunar eclipse positions

A lunar eclipse occurs when the moon passes directly behind Earth into its umbra (shadow).

Solar eclipse positions

A solar eclipse happens when the moon moves in front of the sun.

Patterns.

Earth spins on its axis. It makes one full rotation on its axis every 24 hours. Earth also revolves around the sun. It takes 365 days for Earth to make one full revolution around the sun.

Cycles.

Earth's rotation on its axis and revolution around the sun causes cycles on Earth: day, night, seasons, weather. Other cycles include the phases of the moon, water cycle, and life cycles.

Changes.

Earth goes through various changes. Some changes happen quickly; for example, an earthquake or a storm can change Earth rapidly. Other changes happen slowly; for example, the North American and Eurasian tectonic plates are separated by the Mid-Atlantic Ridge. The two continents are moving away from each other at the rate of about 2.5 centimeters (1 inch) per year (National Geographic, n.d.).

Earth's magnetic poles

Earth has a magnetic field that extends from its interior to outer space. A compass is calibrated based on Earth's magnetic field. Over time, Earth's poles reverse—every 200,000 to 300,000 years. Magnetic fields morph, push, and pull at one another, with multiple poles emerging at odd latitudes throughout the process. Scientists estimate reversals have happened at least hundreds of times over the past 3 billion years. On Earth, the magnetic field S pole is near Earth's geographic North Pole. The magnetic field N pole is near Earth's geographic South Pole. This makes a compass usable for navigation.

Solar system

The solar system is a planetary system that orbits the sun. The solar system consists of the sun and everything that orbits around it. This includes the eight planets and their natural satellites (such as our moon), dwarf planets and their satellites, as well as asteroids, comets, and countless particles of smaller debris (NASA, n.d.).

Order of planets

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

Other Components of the Solar System

• Comets - A chunk of ice and rock originating outside of the solar system.

• Asteroids - A chunk of rock and metal in orbit in between Mars and Jupiter.

• Meteorite - A small asteroid.

Light Year

A light year is a unit of astronomical distance equal to the distance light travels in one year. For example, if an event occurs13 light years away, it will take 13 years to observe the event from Earth.

Speed of Light

The speed of light in a vacuum is approximately 300,000 km/sec. In a vacuum is where speed of light is fastest. Traveling through any other medium, the speed of light is slower.

Solid Earth

Earth is made up of several layers: crust/lithosphere, mantle, and core. Earth gets denser toward the center. The temperature increases deeper into Earth. For example, the mantle is 1900°K, the outer core is 3000°K, and the inner ore is 5000▬7000°K.

Composition Layers

Crust (Lithosphere)

The outermost solid layer of Earth.

0 - 100 km

Mantle

The mantle is not liquid; it is ductile or plastic, which means that some parts of the mantle can flow under certain conditions and changes in pressure. The mantle is mainly composed of aluminum and silicates.

100 - 900 km

Core

The innermost layers of Earth. Earth has an outer core (liquid) and an inner core (solid). The core is mainly composed of nickel and iron.

2900 - 6370 km

Earth's atmosphere

Earth's atmosphere is a layer of gases surrounding the planet. The gases present in Earth's atmosphere are:

• Nitrogen: 78%

• Oxygen: 21%

• Argon: 0.09%

• Carbon dioxide: 0.01%

• Helium: small traces

• Neon: small traces

• Other gases: small traces

Earth's 5 Spheres - Above the Crust

Earth is made up of different types of spheres.

• Lithosphere - The outermost shell of Earth. Earth's crust is the lithosphere.

• Hydrosphere - All the water on Earth in liquid form. For example, lakes, rivers, and oceans are all part of the hydrosphere.

• Biosphere - The global sum of all ecosystems and living organisms.

• Cryosphere - The masses of frozen water. For example, frozen lakes, frozen rivers, frozen oceans, and glaciers are part of the cryosphere.

• Atmosphere - The layer of gases that surround the plane.

The Water Cycle

The water cycle, also called the hydrologic cycle, is a continuous circulation of water throughout Earth and Earth's atmosphere.

• Precipitation is rain and snow.

• Evaporation is when water turns from a liquid to a gas (water vapor).

• Condensation is when water vapor turns back into liquid—water collects as droplets on a cold surface when humid air is in contact with it, forming clouds.

• Transpiration is when plants suck water from roots to the small pores in leaves, releasing the water vapor into the atmosphere.

Earth's atmosphere

Earth's atmosphere also contains multiple layers:

• Troposphere: 0-12 km above Earth. *Most of Earth's weather occurs here.

• Stratosphere: 12-50 km above Earth. *Contains the ozone layer.

• Mesosphere: 50-80 km above Earth. •

Thermosphere: 80-700 km above Earth.

• Exosphere: 700-1000 km above Earth. The ozone layer absorbs 97 - 99% of the sun's ultraviolet light and is contained in the stratosphere. This layer contains high levels of ozone (O3 ).

Two decades of scientific research has shown that human-produced chemicals are responsible for the observed depletions of the ozone layer. (NOAA, n.d.).

Energy resources

Energy resources play a critical role in everyday human life. We use energy to power everything from a coffee machine to the space shuttle. Our energy resources come from the Earth in a variety of forms.

Some energy resources cannot be renewed as quickly as they are being consumed (nonrenewable); some energy resources can be renewed quickly by the Earth's physical processes (renewable).

• Clean energy. Energy from wind, solar, wind, water, geothermal, biomass, and nuclear

• Fossil energy. Energy from coal, oil, and natural gas

• Electric power. Energy from charged particles

Renewable and Nonrenewable Resources

Renewable

solar

wind

hydro power

Non-renewable

fossil fuels

coal

natural gas

Earth's materials

A rock is any naturally occurring solid mass or aggregate of minerals or mineraloid matter. Rocks are categorized by the minerals they include, their chemical composition, and their formation (origin). Rocks are usually grouped into three main categories: igneous, metamorphic and sedimentary. Rocks form the Earth's outer solid layer: the lithosphere.

Types of Rocks

Igneous

lava, magma

glassy, smooth surface, gas bubble holes, random arrangement of minerals

granite, pumice, obsidian

Metamorphic

heat pressure

sparkly crystals, ribbonlike layers

marble, slate, gneiss

Sedimentary

deposition, cementation

sand grains or visible pebbles; fossils may be visible

conglomerate, sandstone, limestone, shale

Soil

Soil is a mixture of minerals, organic matter, gases, liquids, and many organisms that together support life on Earth.

topsoil

subsoil

bedrock

Processes of the lithosphere (crust)

Geologic formations are formations made from rocks that exist on the lithosphere. Examples include volcanoes, mountains, and canyons.

Mountains are formed as a result of Earth's tectonic plates smashing together.

Volcanoes are formed when magma from within Earth's upper mantle erupts through the surface.

Canyons are formed by weathering and erosion caused by the movement of rivers. Canyons are also formed by tectonic activity.

Earthquakes

Earthquakes are usually caused when plates rub against each other in an opposite motion, and rock underground suddenly breaks along a fault. This sudden release of energy causes seismic waves that make the ground shake.

Scientists assign a magnitude rating to earthquakes based on the strength and duration of their seismic waves. A quake measuring 3 to 4.9 is considered minor or light; 5 to 6.9 is moderate to strong; 7 to 7.9 is major; and 8 or more is great.

Seismic waves

A seismic wave is an elastic wave caused by an earthquake. There are three types of seismic waves:

1. Primary (P waves).

These are the fastest waves (5 kilometers per second or approximately 3 miles per second) and can travel through solid, liquids, and gases.

2. Secondary (S waves).

Secondary waves travel through Earth's interior at about half the speed of primary waves. Secondary waves can travel through rock, but unlike primary waves, they cannot travel through liquids or gases.

3. Surface.

Surface waves are seismic waves that move along Earth's surface, not through its interior. Surface waves are the slowest of the three seismic waves.

Tsunamis

Tsunamis are giant waves caused by earthquakes or volcanic eruptions under the sea. Out in the depths of the ocean, tsunami waves do not dramatically increase in height. However, as the waves travel inland, they build up to higher and higher heights as the depth of the ocean decreases. The speed of tsunami waves depends on ocean depth. Tsunamis may travel as fast as jet planes over deep waters, only slowing down when they reach shallow waters (NOAA, 2019).

Plate tectonics is the theory that Earth's outer shell is divided into several plates that glide over the mantle or the rocky inner layer above the core. The plates move and separate, causing Earth to separate and change.

Divergent - Pulling apart

Convergent - Coming together

Subduction - Sideways and downward movement of the edge of a plate into the mantle beneath another plate