Earth Science Notes PDF

Big Bang Theory - A theory states that the universe may have begun 13.8 billion years ago. Everything starts at a single point singularity that later undergoes a violent explosion and to this very moment, it is believed that the universe is gradually expanding. Nebular Hypothesi...

Big Bang Theory - A theory states that the universe may have begun 13.8 billion years ago. Everything starts at a single point singularity that later undergoes a violent explosion and to this very moment, it is believed that the universe is gradually expanding. Nebular Hypothesis - is the most widely accepted theory about the formation of the solar system that may have begun 4.54 billion years ago. - It started in a cold spinning cloud of solar nebula that is later condensed towards the center due to gravitational pull. It then flattened at the center which creates the accretion disk. As matter gradually collects at the center, a ball of hot gas is then created called protostar (Sun). Outside the star, matter was forming into clumps of dust that give to the planets. Planets in the Solar System Mercury is a terrestrial (rocky) planet. It has a solid, cratered surface, much like the Earth's moon. It has a thin atmosphere, or exosphere, is composed mostly of oxygen, sodium, hydrogen, helium, and potassium. Venus has a solid surface covered with extensive plains featuring high volcanic mountains and vast ridged plateaus. The planet’s surface temperature is hot enough to melt lead. Earth is a rocky planet with a solid and dynamic surface of mountains, canyons, plains and more. Most of our planet is covered in water. The atmosphere is a perfect balance for us to breathe and live. Mars is a rocky planet. Its surface has been altered by volcanoes, impacts, winds, crustal movement, and chemical reactions. It has a thin atmosphere made up of a small amount of oxygen and water vapor. Jupiter is the biggest planet in our solar system. It is made of gas so lacks an Earth-like surface. Its atmosphere is made up mostly of hydrogen and helium. Saturn’s is a gas-giant planet and therefore does not have a solid surface like Earth’s. But it might have a solid core somewhere in there. Uranus and Neptune are both made up of a thick soup of “icy" materials – water, methane, and ammonia – above a small rocky core. Their atmospheres are made mostly of molecular hydrogen and atomic helium, with a small amount of methane. Terrestrial/Rocky Planets: Mercury, Venus, Earth, and Mars Gaseous/Jovian Planets: Jupiter, Saturn, Uranus, Neptune What makes planet Earth our home special? What are its unique characteristics that make it the only planet in the Solar System to support life? TEMPERATURE AND WATER The Earth is a “Goldilocks Planet” because it has the right distance from the Sun to allow temperatures for liquid water to exist. It is neither too hot nor too cold. It is also the only planet in the Solar System that contains liquid water on its surface. Life seems to be limited to a temperature range -15°C to 115°C. In this range, liquid water can exist under certain conditions. ATMOSPHERE The Earth’s atmosphere keeps the surface warm and provides chemicals needed for life, such as nitrogen, carbon dioxide, and oxygen. It also protects all organisms on Earth from harmful radiation and small to medium-sized meteorites. ENERGY The Earth has a steady source of light energy and contains energy-rich chemicals. With a steady input of either light or chemical energy, cells can run the chemical reactions necessary for life. NUTRIENTS The Earth has mechanisms that circulate nutrients. Some of these include the water cycle, the atmosphere, and volcanism. THE EARTH’S FOUR SUBSYSTEMS GEOSPHERE The geosphere contains several layers of land. The layers are physically and chemically different. The topmost layer consists of loose soil rich in nutrients, oxygen, and silicon. HYDROSPHERE The hydrosphere contains all the solid, liquid, and gaseous water of the planet. Ninety-seven percent of Earth's water is salty mainly found in seas and oceans. BIOSPHERE The biosphere contains all the planet's living things. This sphere includes all the microorganisms, plants, and animals of Earth. ATMOSPHERE The atmosphere contains all the air in Earth's system. It is composed of the following mix of gases in differing amounts: nitrogen 78% oxygen 21% argon 0.9% carbon dioxide, nitrous oxides, methane, and ozone (very low amounts) Water Cycle The water cycle is a global cycle. It takes place on, above, and below Earth’s surface. It moves water in all the four subsystems through the following processes.  Evaporation occurs when water on the surface changes to water vapor. The sun heats the water and gives water molecules enough energy to escape into the atmosphere. Sublimation occurs when ice and snow change directly to water vapor. This also happens because of heat from the sun. Transpiration occurs when plants release water vapor through leaf pores called stomata. Condensation is the process in which water vapor changes to tiny droplets of liquid water. The water droplets may form clouds. Precipitation, such as rain, is the falling of water droplets from the clouds. Eventually, this water evaporates again and repeats the water cycle. Most precipitation falls into the ocean and some will end up as either surface runoff or groundwater. Surface runoff is water from precipitation that flows over the surface of the ground. It may eventually flow into a body of water. Groundwater is water from precipitation that is soaked into the ground. Rock Cycle It is a type of process responsible for degradation, sculpting, and transforming the types of rocks in Earth's crust. Three Types of Rocks Type of Rock Where can be found Physical Examples Composition Igneous Inside/near a volcano crystals Granite, basalt, granite Sedimentary Ocean, river Sediments, fossils Sandstone, limestone, shale Metamorphic Mountain ranges distinctive layering Marble, quartzite, schist Mineral Minerals are the building blocks of rocks. It is defined as naturally formed, generally inorganic, crystalline solid composed of an ordered array of atoms and having a specific chemical composition. Physical Properties of Minerals Luster - refers to the way light is reflected from a mineral surface. Hardness - refers to the minerals resistance to being scratched. - Moh’s Scale of Hardness - The scale test compares the resistance of a mineral to being scratched by ten reference minerals. Moh’s Scale of Hardness Mineral Hardness Mineral Hardness Talc 1 (Softest) Orthoclase 6 Gypsum 2 Quartz 7 Calcite 3 Topaz 8 Fluorite 4 Corundum 9 Apatite 5 Diamond 10 (Hardest) Streak - along a thin line or mark of a different substance or color from its surroundings. Cleavage - is the tendency of minerals to break along planes of weak bonding. Fracture - minerals that do not exhibit cleavage are said to fracture when broken. Color - some are of the same color like azurite is always deep blue, sulfur is yellow. Specific gravity - is a number which represents the ratio to the weight of an equal volume of water. Crystal form - external features of a mineral reflect its orderly internal arrangements of atoms. References: Olivar II, J. T , Rodolfo, R., and Cabria, H. (2016). Exploring Life Through Science Series. Phoenix Publishing House, Inc, pp. 3-12. Micame, L. (2021). Earth Science Quarter 1-Module: What makes the Earth Fit For Life? (2nd Ed.). Department of Education. Micame, L. (2021). Quarter 1 - Module 2: The Earth’s Subsystems (2nd Ed.). Department of Education. Tabada, M. R. (2021). Quarter 1 – Module 1: Planet Earth - Our Unique Home (2nd Ed.). Department of Education. Revales, A. (2021). EARTH and LIFE SCIENCE First Quarter – Module 2 - Minerals, Rocks and Exogenic Processes (2nd Ed.). Department of Education.