The Solar System The Planets

Celestial Bodies Is an old term that means the sun, moon and stars Is an old term that means the sun, moon and stars Thousands of years ago Farmers took cues from these bodies for planting crops Farmers took cues from these bodies for planting crops Sailors used the stars for navigation Sailors used the stars for navigation Politics and religion decisions were sometimes made by the celestial bodies Politics and religion decisions were sometimes made by the celestial bodies

What is the difference between a planet and a dwarf planet? A Planet is A celestial body larger than an asteroid or comet, lit by the light of the sun around which it orbits A planet is is in orbit around the Sun, Large enough mass to be round in shape has cleared the neighbourhood around its orbit (which means that there are no other large celestial bodies under its gravitational pull)

A Dwarf Planet is… A "dwarf planet" is a celestial body that is in orbit around the Sun, Large enough mass to have a nearly round in shape has NOT cleared the neighbourhood around its orbit which means that there are other larger bodies impacted by its gravitational pull

Types of Planets Terrestrial Planets Terrestrial Planets Jovian Planets Jovian Planets Dwarf Planets Dwarf Planets

Terrestrial Planets Smaller size and mass Smaller size and mass Higher density Higher density Made mostly of rock and metal Made mostly of rock and metal Solid surface Solid surface Few, if any, moons Few, if any, moons No rings No rings Closer to the Sun and each other Closer to the Sun and each other Warmer surfaces Warmer surfaces Mercury, Venus, Earth, Mars Mercury, Venus, Earth, Mars

Mercury Diameter = 4872 km Diameter = 4872 km Distance to the Sun =57.9 million km Distance to the Sun =57.9 million km

Mars Diameter =6 780 km Diameter =6 780 km Distance to the Sun =227.9 million km Distance to the Sun =227.9 million km

Venus Diameter =12 104km Diameter =12 104km Distance to the Sun = million km Distance to the Sun = million km

Earth Diameter = km Diameter = km Distance to the Sun =149.6 million km Distance to the Sun =149.6 million km Orbit period = days Orbit period = days Orbit speed = km/s Orbit speed = km/s Axis rotation = hours Axis rotation = hours Axis tilt = 23.5 o Axis tilt = 23.5 o Acceleration = 9.81 m/s 2 Acceleration = 9.81 m/s 2

Jovian Planets Larger size and mass Larger size and mass Lower density Lower density Mostly made of hydrogen, helium, and hydrogen compounds Mostly made of hydrogen, helium, and hydrogen compounds No solid surface No solid surface Many moons Many moons Rings Rings Farther from the sun and each other Farther from the sun and each other Cool temperatures at cloud tops Cool temperatures at cloud tops Jupiter, Saturn, Uranus, Neptune Jupiter, Saturn, Uranus, Neptune

Jupiter Diameter = km Diameter = km Distance to the Sun =778.4 million km Distance to the Sun =778.4 million km

Saturn Diameter = km Diameter = km Distance to the Sun =1.4 billion km Distance to the Sun =1.4 billion km

Uranus Diameter = km Diameter = km Distance to the Sun =2.4 billion km Distance to the Sun =2.4 billion km

Neptune Diameter = km Diameter = km Distance to the Sun = 4.5 billion km Distance to the Sun = 4.5 billion km

Dwarf Planets Remember a Remember a "dwarf planet" is a celestial body that is in orbit around the Sun, Large enough mass to have a nearly round in shape has NOT cleared the neighbourhood around its orbit which means that there are other larger bodies impacted by its gravitational pull Pluto, Ceres, Eris Pluto, Ceres, Eris

Ceres Diameter = 974.6km Diameter = 974.6km Distance to the Sun = km Distance to the Sun = km

Pluto Diameter =2 306km Diameter =2 306km Distance to the Sun = km Distance to the Sun = km

Eris Diameter =2 600km Diameter =2 600km Distance to the Sun = AU Distance to the Sun = AU

How do we determine how far apart the planets are?

Bode’s Law A rough rule that predicts the spacing of the planets in the Solar System To find the mean distances of the planets, beginning with the following simple sequence of numbers: With the exception of the first two, the others are simple twice the value of the preceding number. Add 4 to each number: Then divide by 10: Planet Actual Distance (AU) Bode’s Law Mercury Venus Earth Mars Jupiter Saturn Uranus Neptune Works for moons too!

How do the solar system bodies orbit the sun?