Solar System PDF

OBJECTIVES: 1. TO BE ABLE TO BRIEFLY ENUMERATE AND EXPLAIN THE DIFFERENT THEORIES OF THE ORIGIN OF SOLAR SYSTEM ASTRONOMY ❖ Astronomy is a natural science that study of celestial objects (such as stars, galaxies, planets, moons, asteroids, comets and nebulae), the phys...

OBJECTIVES: 1. TO BE ABLE TO BRIEFLY ENUMERATE AND EXPLAIN THE DIFFERENT THEORIES OF THE ORIGIN OF SOLAR SYSTEM ASTRONOMY ❖ Astronomy is a natural science that study of celestial objects (such as stars, galaxies, planets, moons, asteroids, comets and nebulae), the physics, chemistry, and evolution of such objects, and phenomena that originate outside the atmosphere of Earth, including supernovae explosions, gamma ray bursts, and cosmic microwave background radiation.  THEORIES OF ORIGIN OF THE SOLAR SYSTEM THE BASIC EVOLUTIONARY THEORY  The earliest accounts of how the Sun, the Earth and the rest of the Solar System were formed are to be found in early myths, legends and religious texts. None of these can be considered a serious scientific account.  The earliest scientific attempts to explain the origin of the solar system invoked collisions or condensations from a gas cloud. The discovery of 'island universes', which we now know to be galaxies, was thought to confirm this latter theory. #1: NEBULAR HYPOTHESIS  The theory: Hydrogen and other gases swirled around and condensed into our sun and its planets.  The nebular hypothesis was originally proposed in 1755 by Immanuel Kant and was presented in 1796 by Pierre Simon Laplace which became Laplace Nebular model. #1: NEBULAR HYPOTHESIS A modern variation of the nebular hypothesis that took off from the Laplace model, the Solar Nebular Disc Model (SNMD) was drawn by Victor Sergeevich Safranov, a Russian astronomer. Modern Theory (SNDM): His model predicted the formation of a nebular disc, which is made up of accreted gas and dust clouds around the protosun from which the planets are formed. SNDM- SOLAR NEBULAR DISC MODEL The eventual discovery of the gas and dust cloud validated this model to become the currently accepted model or explanation about the formation of the solar system. It can explain the disc shape of our solar system, where the planets orbits the sun along the same plane and in the same direction of revolution and rotation. ASTEROID BELT KUIPER BELT AND OORT CLOUD #2: FISSION THEORY  The theory: One day our sun burst open, and planets and moons shot out at high speeds and went to their respective places, then stopped, and started orbiting the sun, as the moons began orbiting the planets. #3: CAPTURE THEORY  The theory: Planets and moons were flying around, and some were captured by our sun and began circling. #4: ACCRETION THEORY  The theory: A pile of space dust and rock chunks pushed together into our planet, and another pile pushed itself into our moon. Then the moon got close enough and began encircling the earth. # 5: PLANETARY COLLISION THEORY  The theory: Our world collided with a small planet, and the explosion threw off rocks which became the moon, and then it began orbiting us. #6: STELLAR COLLISION THEORY  The theory: Our planets, moons, and suns spun off from the collision between stars. #7: GAS CLOUD THEORY  The theory: Gas clouds were captured by our sun. But instead of being drawn into it, they began whirling and pushing themselves into planets and moons. BIRTH OF STARS A Star is born when interstellar clouds, called nebulae (latin for clouds), contract on its gravity and begin to rotate. The rotation of this mass arranges the material into the shape of a flat disc. As the mass grows and become denser, it forms stellar core. As more materials get into the core, it emits ultraviolet radiation due to increased core temperature. The core eventually ignites and emits light. This process creates protostar. INTERSTELLAR CLOUDS  Main sequence star- core of the protostars should be hotter than 10 million K in order for nuclear fusion to occur. (Fusion happens when sub atomic particles collide at high speed to form a new atomic nucleus.)  Otherwise if the core temperature of a protostar does not attain a temperature higher than 10 million K, it becomes what is known as a “brown dwarf”, or “failed star”. The faster the insterstellar cloud to rotate, the more stars will be formed.  Stars twinkle in blue- have the highest temperature.  Stars twinkle in red- (dimnest) have the lowest temperatures.  The gaseous core of stars are exhaustible and are continuously being burned, there will come a time when these elements are consumed and its core will collapse and it will began to die.  After star implodes, it instantaneously and catastrophically expands. This process of expansion leads to the formation of supernova or an “exploding star”. Did you know that… Collapsing or exploding stars, whose cores are three or more times larger than the mass of our Sun, form a black hole. Black hole- exceptionally dense body with an extremely powerful gravitational field that attracts anything in it. FORMATION THE SUN  Solar nebula or the galactic clouds where our sun was formed collided with supernova. This collision caused the resulting nebula to spin, which pulled and concentrated the gas and dust clouds to its center. These materials struck each other, causing the cloud temperature to shoot up and ignite to brighten the clouds. FORMATION OF PLANETS  When a temperature of 10 million K is reached, the process of nuclear fusion happens which powers up the formation of stable and heavy elements. These heavy elements constituted the materials needed for the formation of protoplanets in our solar system.  The formation of the protosun and the protoplanets in our solar system happened in a time span of at least 100 million years. FORMATION OF EARTH  The Earth was created 4.6 billion years from the accretion of cold nebular clouds after our sun was formed. It primordial surface was eventually heated by the impacts of asteroids, comets, and other debris from space that collided with the earth. The sun and our planets grossly share the same chemical composition of atoms. This chemistry serves as evidence that the cloud materials used in the formation of sun and the planets in our solar system originated from a red giant or an exploded star. Most of these red giant materials were used to form our sun. The rest constituted the nebular disc to form planets, dwarf planets, asteroids, comets, moons, and other rocky objects in our solar system. FORMATION OF THE MOON  The origin of our moon is known as Giant Impact Hypothesis. It was formed after the formation of the solar system, and it originated from a portion of the Earth that was spewed out to space as a result of collision between the earth and an extra- terrestrial body as big as Mars that happened 4.5 billion years ago. CREATIVE PRESENTATIONS ABOUT THE SOLAR SYSTEM 5-7 MINUTES  Guide question: 1. What makes Earth a living planet? 2. Point out major factors why life flourishes in it?