The Origin of the Earth PDF

 explain how the Earth was Objectives 1 formed according to the At the end accretion hypothesis; and of the lesson, you differentiate homogenous should be 2 and heterogenous accretion able to: hypothesis.  explain why water is Obj...

 explain how the Earth was Objectives 1 formed according to the At the end accretion hypothesis; and of the lesson, you differentiate homogenous should be 2 and heterogenous accretion able to: hypothesis.  explain why water is Objectives 3 considered as the medium of life; At the end of the discuss the origin of water 4 formation on Earth; and lesson, you should be able to: enumerate the uses of 5 water.  describe the sun as the 6 major source of energy; Objectives At the end define what the Earth’s 7 energy budget is; and of the lesson, you should be identify the factors able to: 8 affecting Earth’s energy budget. Objectives 9 describe the characteristics of Earth’s atmosphere; and At the end of the identify the importance of lesson, you 10 the hydrologic cycle. should be able to: Lesson 2.1 The Origin of Planet Earth Learn about it! Learn about it!  Learn about it! Accretion Accretion is one of the leading theories for the formation of planet Earth. It is a process that occurs when gravity attracts tiny bits of matter towards an object. Learn about it! The Steps of Accretion Accretion forms planetesimals, which form protoplanets. A protoplanet is a planetary embryo that consists of collection of matter, from which a planet is formed.  Learn about it! Homogeneous Accretion It is when Earth accreted from materials of the same composition after condensation.  Learn about it! Heterogeneous Accretion It is when Earth accreted during condensation, forming a differentiated planet as it grew in size.  Learn about it! Homogeneous Accretion Evidences Loopholes It provides a mechanism The hypothesis cannot explain that explains the presence the abundance of elements of volatile elements in the such as osmium, iridium, core. ruthenium, and rhodium in the mantle.  Learn about it! Heterogeneous Accretion Evidences Loopholes It qualitatively Accretion must be very fast (103 to explains the density 104 years for completion). This rate differences among does not coincide with the occurrence terrestrial planets. of large impact craters. Also, the abundances of iron, calcium, titanium, and aluminum do not coincide with what was predicted by the theory. Lesson 2.2 Water: The Medium of Life  Learn about it! The Hydrosphere The hydrosphere includes all of Earth’s water. Bodies of water are classified into either saltwater or freshwater, based on salinity.  Learn about it! Saltwater Saltwater (oceans and seas) primarily have high salt content.  Learn about it! Freshwater It has zero to very little salt content.  Learn about it! Global Freshwater 2.5% freshwater vs 97.5% saltwater  Learn about it! Properties of Water Density ○ Water is at maximum density at 3.98°C. Heat Capacity ○Water has a relatively high heat capacity, which allows it to resist temperature changes. These properties make aquatic habitats a stable place for organisms to live in, since aquatic habitats can somewhat resist temperature changes.  Learn about it! The Origin of Water on Earth The prevailing hypothesis on the origin of water on Earth suggests that water came from comets that collided with Earth. Other studies suggest that water was already present within Earth since formation as volatiles trapped in magma.  Learn about it! Global Water Usage Lesson 2.3 Sun as the Main Source of Energy  Learn about it! Albedo All objects can either absorb or reflect light. This is a property known as albedo. It has a value that ranges from 0-1. Albedo Values  Learn about it! The Sun The Sun is the Earth’s main source of energy, and powers many of the processes in the planet. Sun as the main source of energy.  Learn about it! The Sun Plants are dependent on the Sun for photosynthesis. Importance of the sun on humans and other life forms.  Learn about it! Solar Energy is Renewable As long as the sun shines, solar energy is available for everyone to utilize. This is advantageous since the sun is an environmentally- friendly source of energy. Utilization of solar energy by using solar panels.  Learn about it! Earth’s Energy Budget Earth’s energy budget is the balance of energy absorbed and energy reflected. 30% of the energy from the sun is reflected and scattered by clouds, atmosphere, and Earth’s light-colored surfaces. Earth’s energy budget  Learn about it! Factors Affecting Earth’s Energy Budget There are certain factors that affect Earth’s energy budget such as: ○the amount of light colored surfaces ○amount of radiation received ○Earth’s axial tilt ○presence of greenhouse gases.  Learn about it! The Greenhouse Effect Greenhouse effect is one of the factors that affects Earth’s energy budget. Lesson 2.4 Earth’s Atmosphere  Learn about it! Atmospheric Composition The bulk of the atmospheric composition of Earth is nitrogen and oxygen in which together comprises 99%. 78% N2, 21% O2 Only 0.9% is argon and the remaining 0.1% is trace gases. Carbon dioxide and ozone, although available in minute amounts, are very essential to life on Earth.  Learn about it! Atmospheric Composition Atmospheric composition of Earth.  Learn about it! Layers of the Atmosphere The atmosphere is made up of 5 major layers ○troposphere, ○stratosphere, ○mesosphere, ○thermosphere, ○exosphere. Layers of the atmosphere  Learn about it! Layers of the Atmosphere Troposphere is where humans and most of the biosphere reside, and is the lowest layer. The troposphere is the layer closest to Earth. Its thickness varies depending on your location on Earth, but the range is between 5 and 9 miles (8 and 14 km).  Learn about it! Layers of the Atmosphere The stratosphere is the next layer which is about 35 km thick. Stratosphere contains the ozone layer.  Learn about it! The Stratospheric and Tropospheric Ozone Stratospheric ozone is good while tropospheric ozone is bad. These harmful ozones when inhaled, can irritate the lungs and breakdown lung tissues. Plants are also affected by this tropospheric ozone. Good and bad ozone.  Learn about it! Layers of the Atmosphere This 35 km thick layer is termed as the coldest layer because it has a minimum temperature of roughly -85 degrees Celsius. Mesosphere is where meteorites burn up.  Learn about it! Layers of the Atmosphere Thermosphere is a layer with extremely high temperatures. Thermosphere is roughly 600 km thick and can reach a temperature of about 1500 degrees Celsius.  Learn about it! Layers of the Atmosphere Exosphere is the outermost layer of the atmosphere, and the layer in contact with outer space. This 10,000 km thick.  Learn about it! Layers of the Atmosphere Troposphere is where humans and most of the biosphere reside, and is the lowest layer. Stratosphere contains the ozone layer. Mesosphere is where meteorites burn up. Thermosphere is a layer with extremely high temperatures. Exosphere is the outermost layer of the atmosphere, and the layer in contact with outer space.  Learn about it! Atmosphere’s Role in the Hydrologic Cycle The atmosphere is a crucial part of the water cycle. It serves as the reservoir of large amounts of water. Therefore, the atmosphere is an efficient medium to move water around the globe. Steps in the hydrologic cycle