The Solar SystemThe Solar System

The PlanetsThe Planets

Celestial BodiesCelestial Bodies

Is an old term that means the sun, Is an old term that means the sun, moon and starsmoon and stars

Thousands of years agoThousands of years ago Farmers took cues from these bodies Farmers took cues from these bodies

for planting cropsfor planting crops Sailors used the stars for navigationSailors used the stars for navigation Politics and religion decisions were Politics and religion decisions were

sometimes made by the celestial sometimes made by the celestial bodiesbodies

What is the difference What is the difference between a planet and a between a planet and a

dwarf planet?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 "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 PlanetsTypes of Planets

Terrestrial PlanetsTerrestrial Planets Jovian PlanetsJovian Planets Dwarf PlanetsDwarf Planets

Terrestrial PlanetsTerrestrial Planets Smaller size and massSmaller size and mass Higher densityHigher density Made mostly of rock and metalMade mostly of rock and metal Solid surfaceSolid surface Few, if any, moonsFew, if any, moons No ringsNo rings Closer to the Sun and each otherCloser to the Sun and each other Warmer surfacesWarmer surfaces Mercury, Venus, Earth, MarsMercury, Venus, Earth, Mars

MercuryMercury

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

km km

MarsMars

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

kmkm

VenusVenus

Diameter =12 104kmDiameter =12 104km Distance to the Sun = 108.2 million Distance to the Sun = 108.2 million

kmkm

EarthEarth

Diameter =12 756 kmDiameter =12 756 km Distance to the Sun =149.6 million Distance to the Sun =149.6 million

kmkm Orbit period = 356.26 daysOrbit period = 356.26 days Orbit speed = 108 000 km/sOrbit speed = 108 000 km/s Axis rotation = 23.93 hoursAxis rotation = 23.93 hours Axis tilt = 23.5Axis tilt = 23.5oo

Acceleration = 9.81 m/sAcceleration = 9.81 m/s22

Jovian PlanetsJovian Planets Larger size and massLarger size and mass Lower densityLower density Mostly made of hydrogen, helium, and Mostly made of hydrogen, helium, and

hydrogen compoundshydrogen compounds No solid surfaceNo solid surface Many moonsMany moons RingsRings Farther from the sun and each otherFarther from the sun and each other Cool temperatures at cloud topsCool temperatures at cloud tops Jupiter, Saturn, Uranus, NeptuneJupiter, Saturn, Uranus, Neptune

JupiterJupiter

Diameter =142 984 kmDiameter =142 984 km Distance to the Sun =778.4 million Distance to the Sun =778.4 million

kmkm

SaturnSaturn

Diameter =120 536 kmDiameter =120 536 km Distance to the Sun =1.4 billion kmDistance to the Sun =1.4 billion km

UranusUranus

Diameter =51 118 kmDiameter =51 118 km Distance to the Sun =2.4 billion kmDistance to the Sun =2.4 billion km

NeptuneNeptune

Diameter =49 532 kmDiameter =49 532 km Distance to the Sun = 4.5 billion kmDistance to the Sun = 4.5 billion km

Dwarf PlanetsDwarf Planets

Remember aRemember 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, ErisPluto, Ceres, Eris

CeresCeres

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

413 832 587.5 km413 832 587.5 km

PlutoPluto

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

5 906 376 272km5 906 376 272km

ErisEris

Diameter =2 600kmDiameter =2 600km Distance to the Sun = 67.665AUDistance to the Sun = 67.665AU

How do we determine how How do we determine how far apart the planets are?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:

0 3 6 12 24 48 96 192 384•With the exception of the first two, the others are simple twice the value of the preceding number.

•Add 4 to each number:4 7 10 16 28 52 100 196 388

•Then divide by 10:0.4 0.7 1.0 1.6 2.8 5.2 10.0 19.6 38.8

PlanetPlanet Actual Distance (AU)Actual Distance (AU) Bode’s LawBode’s Law

MercuryMercury 0.390.39 0.40.4

VenusVenus 0.720.72 0.70.7

EarthEarth 1.001.00 1.01.0

MarsMars 1.521.52 1.61.6

Jupiter Jupiter 5.205.20 5.25.2

SaturnSaturn 9.549.54 10.010.0

UranusUranus 19.219.2 19.619.6

NeptuneNeptune 30.130.1 38.838.8

Works for

moons too!

How do the solar system How do the solar system bodies orbit the sun?bodies orbit the sun?