Presentation on theme: "Unit 2: The Solar System Mrs. Williams 8 th Grade."— Presentation transcript:
Unit 2: The Solar System Mrs. Williams 8 th Grade
The Big Idea Planets and a variety of other bodies form a system of objects orbiting the sun.
The Center of the Solar System Unit 2 Lesson 1 Historical Models of the Solar System Solar system - the sun & all of the bodies that orbit the sun. Heliocentric model – Sun centered, Earth and the other planets orbit the sun. Geocentric model – Earth centered, the sun, moon and planets circling the Earth
In the beginning… Aristotle ( BCE)- believed in a geocentric model, part of his logic was that we could feel no motion on Earth, so Earth couldn’t be moving. He thought we should detect a shift in position between nearby stars and far away ones. Parallax- apparent shift in the position of an object wen viewed from different locations. Unit 2 Lesson 1 Historical Models of the Solar System
Aristarchus (about BCE)- proposed a heliocentric model, his attempts to measure relative distances to moon & sun have been major contribution to science Unit 2 Lesson 1 Historical Models of the Solar System
Ptolemy- ( CE) believed in a geocentric model. His model was used for 14 centuries. Planets moved on small circles that in turn moved on larger circles (“wheels-on-wheels”) Allowed people to predict the motions of planets years into the future. Unit 2 Lesson 1 Historical Models of the Solar System
Copernicus- ( ) believed in a heliocentric model with perfect circles Kepler- ( ) Realized that planetary orbits were not circular but were more like ellipses. Unit 2 Lesson 1 Historical Models of the Solar System
Galileo Galilei ( ) Improved the telescope in 1609 Observed Jupiter’s moons, Io, Europa, Callisto, and Ganymede which gave support of heliocentric model Observed Venus’s phases Unit 2 Lesson 1 Historical Models of the Solar System
Gravity - force of attraction between objects that is due to their masses & the distances between them. Every object in the universe pulls on every other object. Orbit - path that a body follows as it travels around another body in space. Unit 2 Lesson 2 Gravity & the Solar System
Kepler’s Three Laws 1. Planetary orbits are ellipses with the sun at one focus Aphelion- where the object is farthest from the sun. Perihelion - where the object is closest to the sun. 1. Planets move faster in their orbits when they are closer to the sun. 2. Distance of a planet from the sun to the time the planet takes to go once around its orbit. Unit 2 Lesson 2 Gravity & the Solar System
Law of Gravitational Force Law of universal gravitation- states that all objects in the universe attract each other through gravitational force. Centripetal force -inward force that causes an object to move in a circular path. When planets orbit the sun, a force similar to centripetal force prevents them from moving out of their orbits and into a straight line. The sun’s gravity is the force that keeps the planets moving in orbit around the sun. Unit 2 Lesson 2 Gravity & the Solar System
How the Solar System Formed Theory Solar Nebula - inward pull of gravity is balanced by the outward push of gas pressure in the cloud (perhaps the explosion of a nearby star) Planetesimals - Collisions between these bodies formed larger bodies from which planets formed
Here Comes the Sun Corona-outer atmosphere of the sun (up to 2,000,000 ˚C) Chromosphere- middle layer of sun’s atmosphere (6,000 ˚C) Photosphere- visible surface of the sun. Energy escapes into space (5,527 ˚C) Unit 2 Lesson 3 The Sun
Convective Zone – energy travels by convection from the radiative zone to the photosphere Radiative Zone - energy is transferred away from the core by radiation. Core – very dense center of sun. Temperature of 15,000,000 ˚ C, where nuclear fusion occurs. Unit 2 Lesson 3 The Sun
Solar Activity Sunspots-dark areas that form on the surface of the sun. Unit 2 Lesson 3 The Sun Solar flare – an explosive release of energy that can extend outward as far as the sun’s outer atmosphere Prominence- huge loops of relatively cool gas that extend outward from the photosphere
- process by which two or more low- mass atomic nuclei fuse to form another, heavier nucleus. Nuclear Fusion - process by which two or more low- mass atomic nuclei fuse to form another, heavier nucleus. Three Steps of Nuclear Fusion in the Sun 1. Deuterium - 2 H + collide (1 P, 1 N- a heavy hydrogen) 2. Helium-3 – deuterium combines w/ another H + (more energy/ gamma rays released) 3. Helium-4 – 2 He-3 nuclei combine to form He-4 (more energy/pair of H+ released) turn to pgs Unit 2 Lesson 3 The Sun
Mixing It Up By Radiation – energy leaves the core in the form of electromagnetic waves By Convection – energy (heat) is transferred by the circulation or movement of matter Unit 2 Lesson 3 The Sun
Extreme to the Core Unit 2 Lesson 4 The Terrestrial Planets Terrestrial planets - the four small, dense, rocky planets that orbit closest to the sun astronomical unit (AU) - average distance between the sun & Earth, or approximately 150 million km.
Mercury Period of Rotation-last almost 59 Earth days Period of revolution-88 days Temps range from - 184˚C to 427˚C Smallest planet with craters Venus Retrograde rotation (clockwise) Rotation- 243 Earth days Revolution- 225 days Temp- 465 ˚C; CO 2 traps the sun’s energy Thousands of volcanoes & craters Sulfuric acid rain Unit 2 Lesson 4 The Terrestrial Planets
Earth Only planet that supports life Liquid water, energy soursce Atmosphere contains O 2 Only planet divided into tectonic plates Mars Rotation- 24 h 37 min Revolution Earth years Olympus Mons- largest volcano/mtn in solar system Valles Marineris – longest canyon in solar system Thin CO 2 atmosphere Unit 2 Lesson 4 The Terrestrial Planets
A Giant Among Giants! Gas giants have deep, massive gas atmospheres, made up mostly of hydrogen & helium. No surface to stand on. Large and cold. Unit 2 Lesson 5 The Gas Giant Planets
Jupiter Rotates fastest – 9 h 55 min Revolution– Earth years Great Red Spot 63 moons Io Europa Callisto Ganymede Saturn Rotation- 10 h 39 min Revolution years Planetary ring system Made of H + & He 60 moons Enceladus Titan Unit 2 Lesson 5 The Gas Giant Planets
Uranus Rotation- 17 h 24 min Revolution-84 years Made of H + & He Atmosphere of methane Tilted on its side as it orbits the sun 27 moons Miranda Neptune Rotation-16 h 7 min Revolution years H + /He and methane Great dark spot 13 moons Triton-orbits opposite Unit 2 Lesson 5 The Gas Giant Planets
Small Bodies in the Solar System dwarf planets- celestial body that orbits the sun, is round because of its own gravity. Ceres (between Mars & Jupiter) Pluto Haumea Makemake Eris
Kuiper Belt- orbits just beyond Neptune Kuiper belt object (KBO) -any of the minor bodies in the Kuiper belt. They are made of methane ice, ammonia ice, and water ice.
Comets Comet -small body of ice, rock, & dust that follows a highly elliptical orbit around the sun. Oort cloud - spherical region tht surrounds the solar system
On the Rocks Asteroid – small, irregularly shaped, rocky object that orbits the sun. Most located in the asteroid belt between the orbits of Mars and Jupiter Some are rich in carbon, others rocky with cores or iron and nickel
Burned Out Meteoroid -rocky body, ranging in size from that of a sand grain to that of a boulder, which travels through space. Meteor -bright streak of light that results when a meteoroid burns up in Earth’s atmosphere. Meteorite - a meteoroid that reaches Earth’s surface without burning up.