The Solar System Solar System the sun and

The Solar System

Solar System • the sun and all things orbiting around it, including the eight major planets, their satellites, and all the smaller pieces such as asteroids, meteoroids, and comets Not to scale Image taken from: http: //asm. arc. nasa. gov/Gallery/images/generic/LG_Capableofeverything. jpg

Formation of the Solar System Formed around 4. 6 billion years ago Solar Nebula Huge cloud of gas and dust that collapsed into a flattened disk Disk Sun formed at the center of the disk while other objects (planets, moons, etc. ) formed from the whirling material of the disk Solar System Much of the material was cleared away. The Sun, planets, and other objects remained Images taken from: http: //astronomyonline. org/Solar. System. Formation. asp

Planet • derived from a Greek word that means “wanderer” • a major object which orbits around a star • in our solar system, there are eight such objects which are traditionally called “planets”

Orbit • the path of an object in space as it travels around another object • planets orbit around the sun in an elliptical (flattened circle or oval) path; proposed by Johannes Kepler’s 1 st Law • due to the gravitational attraction, a planet’s (or other object’s) speed increases as it approaches the sun • Planetary Motion Not to scale The Earth animation is not rotating in the correct direction; it should be rotating from west to east What do you think is the relationship between a planet’s orbit and a “year? ”

Mass vs. Weight Mass Weight • a measure of how much matter an object is made of • does not change, regardless of where something or someone is • the force of gravity on an object • equal to the mass of the body times the local acceleration of gravity Why do you think the person’s weight is less on the moon? The Earth animation is not rotating in the correct direction; it should be rotating from west to east Mass = 59 kg Weight = 579 N Weight = 96 N http: //www. exploratorium. edu/ronh/weight/index. html

Rotation vs. Revolution Rotation • • • the movement or path of the earth or a heavenly body turning on its axis equivalent to one “day” Earth rotates at a speed of around 1, 670 km/hr or 1000 mi/hr The Earth animation is not rotating in the correct direction; it should be rotating from west to east • • the motion of one body around another, such as Earth orbiting around the sun also known as an orbital period equivalent to one “year” Earth revolves at a speed of around 107, 000 km/hr or 67, 000 mi/hr Sun Tips for remembering: rotation occurs in one day; day has three letters and rotation has three syllables revolution occurs in one year; year has four letters and revolution has four syllables

Factors Influencing Planetary Characteristics Impact Cratering a process that occurs when a round pit is left behind on the surface of a planet or other body in space after a smaller object strikes the surface The Earth animation is not rotating in the correct direction; it should be rotating from west to east Tectonics the process of change in a crust due to the motion of hot material underneath Animation taken from: http: //www. odsn. de/odsn/services/paleomap/animation. htm l Volcanism the process of molten material moving from a space body’s hot interior onto its surface Weathering and Erosion Weathering - the breaking down of rocks into smaller pieces; mostly caused by movements of water, wind, and ice Erosion – the process in which sediment is picked up and moved from one place to another

Atmosphere Radiant energy from the sun • the outer layer of gases of a large body in space, such as a planet or star • usually composed of layers • Greenhouse Effect – the trapping of radiant energy by the gases (CO 2, CH 4, H 2 O, among others) that compose the atmosphere – planetary conditions would be very different without it (i. e. – the Earth’s temperature would be 60 o. F cooler we would not survive) The Earth animation is not rotating in the correct direction; it should be rotating from west to east What do you notice about the amount of energy entering the atmosphere, compared to the amount leaving?

Image taken from: http: //www. ucar. edu/learn/1_1_1. htm

Planet Classifications • Terrestrial Planets (inner planets) – Mercury, Venus, Earth, Mars – closest to the sun – composed primarily of rock and metal – have deep atmospheres (except Mercury), solid surfaces, no rings, & few satellites • Gas Planets (outer planets) – Jupiter, Saturn, Uranus, Neptune – composed primarily of hydrogen & helium – have deep atmospheres, rings, & many satellites