Reviewer 3rd Quarter Earth Science

1. Constellations a. This lesson focuses on constellations, recognized patterns of stars in the night sky. b. It explores various aspects of constellations, including their formation, characteristics, uses, and relationship to astrology and astronomy. 2. Life Cycle of a Sun a. The lesson presents a diagram illustrating the life cycle of a sun, starting from a stellar nebula and ending with a white dwarf. b. It highlights the stages of an average star: stellar nebula, average star, red giant, red supergiant, planetary nebula, and white dwarf. 3. The Sun a. The Sun is a huge, glowing sphere of hot gas and plasma. b. It is primarily composed of hydrogen (70%) and helium (28%). 4. Constellations a. Definition: A constellation is a recognized pattern of stars in the night sky. b. Origin: The word "constellation" comes from the Latin "constellacio," meaning "a set of stars." c. Number: There are approximately 400 billion stars in our galaxy and about 170 billion galaxies. d. Historical Significance: Stars have been important to civilizations throughout the world for navigation, religious practices, marking seasons, and defining calendars. 5. Uses of Constellations a. Calendar: In ancient times, constellations were used to create and track calendars for planting and harvesting crops. b. Navigation: Constellations aided sailors in navigating across oceans. c. Landmarks: Constellations serve as fixed landmarks in the sky. 6. Constellations for Navigation a. Ursa Minor: Finding Ursa Minor helps spot the North Star (Polaris). b. North Star: The height of the North Star in the sky allows navigators to determine latitude. 7. Polaris a. Polaris is almost directly above the North Pole. b. It appears to stay in the same spot in the sky while other stars rotate around it. c. This makes it ideal for creating circular star trails. 8. The International Astronomical Union (IAU) a. The IAU divides the sky into 88 official constellations with exact boundaries. b. This ensures that every place in the sky belongs within a constellation. 9. Constellations and Seasons a. Revolution: The Earth's revolution around the Sun is responsible for seeing different parts of the sky at different times of the year. b. Seasonal Visibility: Some constellations are only visible during certain seasons. 10. Winter Constellations a. Visibility: Winter constellations are best observed in the evening night sky from late December to late March in the northern hemisphere and from late June to late September in the southern hemisphere. b. Examples: Auriga, Canis Major, Canis Minor, Carina, Eridanus, Monoceros, Orion, and Taurus. 11. Spring Constellations a. Visibility: Spring constellations are best seen in the evening night sky from late March to late June in the northern hemisphere and from late September to late December in the southern hemisphere. b. Examples: Ursa Major, Boötes, Leo, Cancer, Virgo, and Hydra. 12. Summer Constellations a. Visibility: Summer constellations are best seen in the evening night sky from late June to late September in the northern hemisphere and from late December to late March in the southern hemisphere. b. Examples: Sagittarius, Scorpio, Hercules, and Ophiuchus. 13. Autumn Constellations a. Visibility: Autumn constellations are best observed in the night sky from late September to late December in the northern hemisphere and from late March to late June in the southern hemisphere. b. Examples: Aquarius, Aries, Gemini, and Pisces. 14. Zodiac a. Definition: The zodiac is a group (or "belt") of constellations that fall along the plane of the ecliptic. b. Sun's Path: The Sun appears to "pass" through these constellations during the year. c. Zodiac Belt: It is a specific region of the sky that extends about 8° north and south of the ecliptic. i. The Zodiac Belt consists of 12 constellations through which the Sun appears to move over the course of a year. These are the constellations that correspond to the 12 zodiac signs in astrology: 1. Aries (The Ram) 2. Taurus (The Bull) 3. Gemini (The Twins) 4. Cancer (The Crab) 5. Leo (The Lion) 6. Virgo (The Maiden) 7. Libra (The Scales) 8. Scorpio (The Scorpion) 9. Sagittarius (The Archer) 10. Capricorn (The Sea Goat) 11. Aquarius (The Water Bearer) 12. Pisces (The Fish) ii. Celestial Bodies: The zodiac belt includes the paths of the Moon and the major planets as they orbit the Sun. iii. Origins: The names and shapes of the zodiac constellations have fascinating origins rooted in ancient cultures and mythology. 15. Constellations a. Taurus: "The Bull" b. Leo: "The Lion" c. Scorpio: "The Scorpion" d. Orion: "The Hunter" e. Aquarius: "Water Bearer" f. Aries: "The Ram" g. Cancer: "The Crab" h. Capricornus: "The Goat" i. Cassiopeia: With a "W" pattern j. Gemini: "The Twins" k. Hydra: "Giant Water Snake" (Longest constellation) l. Ophiuchus: "The Snake Bearer" m. Pisces: "The Fish" n. Sagittarius: o. Virgo: "The Virgin" 16. Ursa Major a. Brightness: Ursa Major is known for its bright stars. b. Asterism: The brightest stars form the asterism "Big Dipper." c. Definition: An asterism is a pattern of stars that is not a constellation, but can be part of one. 17. Ursa Minor a. Brightness: Ursa Minor is also known for its bright stars. b. Asterism: The brightest stars form the asterism "Little Dipper." c. Polaris: The end of the handle of the Little Dipper is the North Star (Polaris). 18. Constellations and Navigation a. Constellations played a significant role in navigation for explorers of the Earth's surface and oceans. b. Navigators created extensive star charts to help them find their way around the planet. 19. Astrology vs. Astronomy a. Astrology: Astrology is not a science. It claims to explain human behavior and earthly events based on the movement of stars and heavenly bodies, even though they do not have a direct relationship. b. Astronomy: Astronomy is a branch of science that studies everything in the universe beyond Earth's atmosphere, including celestial bodies. Volcanoes: I. Introduction • Definition of a Volcano: Any place where gases and melted rock (magma) come out of the ground. • The Pacific Ring of Fire: A major area around the Pacific Ocean known for its frequent volcanic eruptions and earthquakes. II. Types of Volcanic Eruptions • Vulcanian Eruption: Short, powerful bursts of ash, gas, and lava fragments, creating dense ash clouds. • Strombolian Eruption: Characterized by mild blasts and fountain lava. • Pelean Eruption: Highly explosive, involving the collapse of a lava dome, resulting in pyroclastic flows. • Phreatic Eruption: A giant steam explosion, where existing rock is blasted apart by steam, but no new lava erupts. • Plinian Eruption: The most explosive type, producing the tallest eruption columns reaching up to 40-55 kilometers. • Hawaiian Eruption: The weakest and calmest, with very runny lava that flows smoothly. • Phreatomagmatic Eruption: Occurs due to the interaction of magma and water, creating a mix of steam, ash, and volcanic bombs. III. Types of Volcanoes • Dormant Volcano: Has not erupted for a significant period (over 10,000 years) but is still capable of future eruptions. • Inactive Volcano: Has not erupted for tens of thousands to millions of years and is not expected to erupt again. • Active Volcano: Has erupted in the recent past (within the last 10,000 years) or is currently erupting. • Cinder Cone Volcano: Small but steep, formed from bits of rock, ash, and lava thrown into the air. • Composite Volcano: Tall, steep sides, made of layers of lava and ash from both quiet and explosive eruptions. • Shield Volcano: Big, wide domes with gentle slopes, formed from slow and steady eruptions of lava. IV. Formation of Volcanoes • Convergent Boundaries: Two tectonic plates crash into each other, causing one plate to go under the other. The lower plate melts, and the magma rises to the surface, creating a volcano. • Divergent Boundaries: Two tectonic plates move apart, leaving a gap that lets magma from below rise up and create new volcanic land. • Transform Boundaries: Tectonic plates slide past each other, causing friction and heat that melt the crust and create volcanic activity along the fault lines. • Hotspots: Areas where magma rises through land, forming volcanoes over millions of years. V. Factors Affecting Volcanic Eruptions • Viscosity: The thickness or resistance to flow of magma. o Low Viscosity: Leads to explosive eruptions. o High Viscosity: Leads to quiet eruptions. • Silica Content: o More Silica: Higher viscosity. o Less Silica: Lower viscosity. • Temperature: o Higher Temperature: Lower viscosity. Lower Temperature: Higher viscosity. VI. Identifying Active Volcanoes • Monitoring Seismic Activity and Gas Emissions: Detecting tremors and gas releases. • Measuring Temperature of Magma: Assessing the heat of the magma chamber. VII. Active Volcanoes in the Philippines • Mount Mayon, Taal Volcano, Mount Pinatubo, Mount Kanlaon: These are active volcanoes in the Philippines. VIII. Parts of a Volcano • Crater: The opening at the top of a volcano. • Main Vent: The main channel through which magma flows. • Magma Chamber: The underground reservoir of molten rock. • Secondary Vent: A smaller opening on the side of a volcano. • Secondary Cone: A smaller cone that forms around a secondary vent. • Ash, Gas, Steam: Materials released during eruptions. • Volcanic Bombs: Large pieces of lava ejected from the volcano. o Geothermal Energy: I. Introduction • Definition: Geothermal energy is a renewable energy source derived from the heat stored within the Earth's interior. • Geothermal Power Plant: A facility that converts this heat into electricity. II. Key Components of Geothermal Power Plants • Turbine: A machine that spins when steam hits it, generating mechanical energy. • Generator: Converts mechanical energy from the spinning turbine into electrical energy. • Condensation: The process of cooling steam back into water after it passes through the turbine. • Reinjection: Returning used geothermal fluids back into the underground reservoir. III. Types of Geothermal Power Plants • Dry Steam Power Plant: Uses steam directly from a geothermal reservoir to turn the turbine. • Flash Steam Power Plant: Converts high-pressure hot water into steam to spin a turbine. • Binary Cycle Power Plant: Uses heat from underground to vaporize a secondary fluid with a low boiling point, which then turns into steam to spin a turbine. IV. Geothermal Energy in the Philippines • Major Geothermal Power Plants: Tiwi, MakBan, Tongonan, Mindanao. • Philippines' Energy Sources: Coal (59.6%), Natural Gas (18.2%), Renewable Sources (14%). • Philippines' Rank in Geothermal Energy Production: Third in the world. V. Advantages of Geothermal Energy • Renewable: Can be replenished naturally. • Environmentally Friendly: Produces less greenhouse gas emissions compared to coal and natural gas. • Reliable: Provides a consistent source of energy. VI. How Geothermal Power Plants Access Heat • Drilling Wells: Deep wells are drilled to access the hot water and steam trapped beneath the Earth's surface. • Pressure and Temperature: The hot water turns to steam when it reaches the surface due to a decrease in pressure. VII. Why the Philippines is a Leading Geothermal Energy Producer • Volcanic Activity: The Philippines is located in a region with significant volcanic activity, providing a readily available source of geothermal energy. Climate: 1. Climate Zones and Geographic Factors • Climate Zones: Temperate, Tropical, and Polar climates. Latitude & Altitude: Latitude affects climate by determining how much sunlight a region receives, while altitude affects temperature (higher altitude = colder temperatures). • Windward vs. Leeward Sides: Windward sides of mountains receive more rainfall, while leeward sides are drier due to the rain shadow effect. 2. Atmospheric and Oceanic Effects • Coriolis Effect: The deflection of moving air and water due to Earth’s rotation (clockwise in the Northern Hemisphere, counterclockwise in the Southern Hemisphere). • Ocean Currents: Warm currents moderate coastal climates, while cold currents can lead to dry conditions. 3. Climate Change and Its Causes • Greenhouse Effect: Certain gases trap heat in Earth’s atmosphere, keeping the planet warm enough for life. • Global Warming: The long-term increase in Earth's surface temperature due to human activities, especially fossil fuel combustion. • Deforestation: Reduces carbon absorption and contributes to higher CO₂ levels. 4. Climate-Related Consequences • Melting Glaciers: Caused by increased CO₂ emissions and rising global temperatures. • Extreme Weather: Stronger typhoons and longer rainy seasons due to increased evaporation. • Rising Sea Levels: A major consequence of global warming. 5. Solutions to Climate Change • Reducing Carbon Footprint: Using public transportation, renewable energy, and reusable bags. • Renewable Energy: Helps reduce greenhouse gas emissions. 6. Distinguishing Climate from Weather • Weather: Short-term atmospheric conditions. • Climate: Long-term weather patterns in a region. 7. Factors affecting climate: 1. Latitude Latitude affects climate by determining how much direct sunlight a region receives. Areas near the equator receive more direct sunlight and are generally warmer, while regions farther from the equator, like the poles, receive less sunlight and are colder. This explains why tropical regions are hot and polar regions are cold. 2. Altitude Altitude, or elevation above sea level, influences temperature. Higher altitudes have cooler temperatures because air pressure decreases, causing air to expand and lose heat. This is why mountain areas are colder than nearby lowland areas, even if they are at the same latitude. 3. Topography (Windward & Leeward Sides of Mountains) Mountains affect climate by influencing rainfall distribution. The windward side of a mountain receives more rainfall because moist air rises, cools, and condenses into clouds. In contrast, the leeward side is drier because air loses moisture before descending, creating a rain shadow effect. This is why deserts often form on the leeward side of mountain ranges. 4. Distance from the Sea (Continentality Effect) Large bodies of water help regulate temperature, meaning coastal areas experience milder summers and winters. Water heats up and cools down more slowly than land, preventing extreme temperature changes. Inland areas, far from the ocean, experience hotter summers and colder winters because they lack this moderating effect. 5. Ocean Currents Ocean currents influence coastal climates by transferring heat. Warm ocean currents bring warmer and more humid conditions, while cold ocean currents create cooler and drier climates. This is why coastal cities near warm currents have a more stable, moderate climate, while those near cold currents experience cooler temperatures and less humidity. •