The Solar System

What is the Solar System? The Sun and all the objects that orbit the sun under its gravitational influence. oThis includes planets, asteroids, moons, comets, meteoroids. oApproximately 4.6 billion years old.

Ceres PlutoEris Kuiper Belt Surrounds our Solar System “ Dwarf ” Planets/Small Solar System Bodies/Kuiper Objects…whatever you call ‘ em, they are NOT considered PLANETS Largest asteroid in Asteroid Belt Dwarf Planets in Kuiper Belt

THE SUN

MERCURY

VENUS

EARTH

MARS

JUPITER

SATURN

URANUS

NEPTUNE

Inner Planets (Terrestrial) Terrestrial = solid smaller, denser, few satellites or rings, closer to Sun. Mercury, Venus, Earth, Mars

Jovian Planets (Outer) gaseous, less dense, satellites or rings, farther from the Sun, LARGER. Jupiter, Saturn, Uranus, Neptune

Comets A comet is a dirty snowball about the size of an Earth mountain. Comets are chunks of ice and dust whose orbits are usually very long, narrow ellipses. The sun produces solar winds that push the gas from a comet away from the sun, forming the comet’s tail. The tail always points away from the sun.

Asteroids Tens of thousands of rocky objects called asteroids are located in a belt between Mars and Jupiter. This belt is called the Asteroid Belt and might be the leftovers from the formation of the terrestrial planets. A few asteroids have orbits that can cross Earth’s orbit. There is evidence that a large asteroid approximately 6 miles in diameter struck the Earth in the Yucatan region of Mexico about 65 million years ago, resulting in mass extinction.

Meteors Small solid particles from space can be caught by Earth’s gravity. As the objects fall, they are heated by friction with Earth’s atmosphere and burn. The burning objects produce streaks of light visible at night as meteors, or “shooting stars”. Most meteors come from comets or asteroids as they break apart.

Motions of the Planets Planets rotate on an axis. 1 rotation = 1 day Proof of Earth’s Rotation: 1. Coriolis Effect 2.Foucault Pendulum 3.Night and Day 4.Star Trails: stars appear to rotate 15 degrees per hour.

Earth’s axis is tilted 23.5 degrees. Earth rotates 15 degrees per hour. This causes rising and setting of the Sun, Moon, and Stars.

Link for Coriolis Effect demo Link for Star Trails around Polaris Link for Foucault pendulum visual

Motion Continued… A planet’s revolution is its movement around the Sun in a path called an orbit. 1 revolution = 1 Year

Proof of Earth’s Revolution: 1.Different Star Constellations are visible during different points in the year. 2.Earth’s Seasons The shape of each objects orbit around the Sun is called an ellipse. Earth revolves around the Sun 360 degrees per year. (Approx. one degree per day)

Other Orbit Information Planets revolve faster when they are closest to the Sun. –Earth is closer on January 3 rd. –Sun appears larger. Planets revolve slower when they are farther from the Sun. Earth is farthest on July 3 rd. –Sun appears smaller. The orbit of a planet is a balance between inertia and gravitational pull.

1. Which motion causes the constellation Orion to be visible at midnight from NYS in winter but not in summer? (1)Rotation of Earth (2)Rotation of Orion (3)Revolution of Earth (4)Revolution of Orion

2. Earth’s rate of rotation is approximately (1)1 degree per day (2)15 degrees per day (3)180 degrees per day (4)360 degrees per day

3. The bar graph below shows one planetary characteristic, identified as X, plotted for the planets of our solar system. Which characteristic of the planets in our solar system is represented by X? (1)Mass (2)Density (3)Eccentricity of orbit (4)Period of rotation

4. Which statement best describes the age of our solar system and the universe? (1)The universe is at least twice as old as our solar system. (2)Our solar system is at least twice as old as the universe. (3)Our solar system and the universe are estimated to be 5 billion years old. (4)Our solar system and the universe are estimated to be 10 billion years old.

5. The spinning of Earth on its axis causes the apparent rising and setting of the (1)Sun, only (2)Sun and Moon, only (3)Moon and some stars, only (4)Sun, the Moon, and some stars

6. A Foucault Pendulum is used to prove that (1)The sun rotates on its axis (2)The Sun revolves around Earth (3)Earth rotates on its axis (4)Earth revolves around the Sun

7. Compared to the terrestrial planets, the Jovian planets are (1)Smaller and have lower densities (2)Smaller and have greater densities. (3)Larger and have lower densities. (4)Larger and have greater densities.