The SunThe Sun

99.8% of the mass of 99.8% of the mass of the solar system is in the solar system is in the Sun.the Sun.

It controls the motion It controls the motion of all objects in the of all objects in the solar system.solar system.

MercuryMercury

Mostly solid and covered with Mostly solid and covered with craters.craters.

Its small size (smallest planet) Its small size (smallest planet) and high density suggest a and high density suggest a large iron and nickel core. large iron and nickel core.

Its atmosphere is constantly Its atmosphere is constantly being replenished and being replenished and destroyed by solar wind.destroyed by solar wind. This causes extreme This causes extreme

temperature fluctuations (-temperature fluctuations (-173173o C to 427to 427o C)

VenusVenus Venus is similar in size and Venus is similar in size and

composition to Earth (slightly composition to Earth (slightly smaller).smaller).

Thick clouds of Thick clouds of CO2 and and

sulfuric acid cover the planet sulfuric acid cover the planet causing an intense causing an intense greenhouse effect (464greenhouse effect (464o C).).

Retrograde motion – Venus Retrograde motion – Venus rotates clockwise very slowly rotates clockwise very slowly (day is longer than year).(day is longer than year).

EarthEarth Earth is the largest rocky planet and the most dense.Earth is the largest rocky planet and the most dense. Unique properties that allow for life:Unique properties that allow for life:

Presence of liquid water because:Presence of liquid water because: Distance from the SunDistance from the Sun Nearly circular orbitNearly circular orbit Mild greenhouse effectMild greenhouse effect

Protection from radiation:Protection from radiation: Atmosphere absorbs/reflects radiationAtmosphere absorbs/reflects radiation Magnetic fieldMagnetic field

One moon.One moon.

MarsMars Mars is the 2Mars is the 2ndnd smallest smallest

planet.planet. Because if it’s small size Because if it’s small size

and density, Mars has a thin and density, Mars has a thin atmosphere that contains atmosphere that contains mostly carbon dioxide.mostly carbon dioxide.

Water may have once Water may have once existed when Mars had a existed when Mars had a thicker atmosphere.thicker atmosphere.

Mars has two small moons.Mars has two small moons.

Moons of MarsMoons of Mars

PhobosPhobos

DeimosDeimos

JupiterJupiter

The largest planet (1/10The largest planet (1/10thth diameter of the Sun)diameter of the Sun)

Composed mostly of Composed mostly of hydrogen and helium (liquid hydrogen and helium (liquid core, gaseous atmosphere).core, gaseous atmosphere).

Has over 60 moons Has over 60 moons including four large moons.including four large moons.

The Great Red Spot, a huge The Great Red Spot, a huge atmospheric storm that has atmospheric storm that has lasted for at least 300 years.lasted for at least 300 years.

EuropaEuropa It is slightly smaller than It is slightly smaller than

the Earth’s moon.the Earth’s moon. There may be liquid water There may be liquid water

under the ice due to under the ice due to gravitational heating.gravitational heating.

Europa is one of the five Europa is one of the five known moons in the solar known moons in the solar system to have an system to have an atmosphere.atmosphere.

SaturnSaturn 22ndnd largest planet. largest planet. Saturn is less dense than water (H & He). If you could Saturn is less dense than water (H & He). If you could

fit Saturn in a lake, it would float!fit Saturn in a lake, it would float! Rings are leftover debris from asteroid collisions.Rings are leftover debris from asteroid collisions.

250,000 km or more in diameter, but less than 200 meters 250,000 km or more in diameter, but less than 200 meters thick.thick.

Saturn’s Moon - TitanSaturn’s Moon - Titan

Larger than Mercury.Larger than Mercury.Dense atmosphere Dense atmosphere

with nitrogen and with nitrogen and methane.methane.

Cassini Cassini probe probe detected ice and detected ice and water vapor.water vapor.

UranusUranus

33rdrd largest planet. largest planet. Also mostly H & He but Also mostly H & He but

appears blue-green appears blue-green because of the methane because of the methane in its atmosphere.in its atmosphere.

Faint rings detected only Faint rings detected only because they block because they block starlight. starlight.

Knocked sideways by a Knocked sideways by a large passing object.large passing object.

NeptuneNeptune

44thth largest planet and largest planet and furthest from the sun.furthest from the sun.

Existence predicted before Existence predicted before it was discovered.it was discovered.

Like Uranus, the methane Like Uranus, the methane gives Neptune its color.gives Neptune its color.

PlutoPluto

Not a planet.Not a planet. Why?Why?

Smaller than our moon.Smaller than our moon. Comet like composition - Comet like composition -

rock and ice.rock and ice. Irregular orbit.Irregular orbit. One of many similar objects One of many similar objects

in the outer reaches of the in the outer reaches of the solar system - dwarf planets.solar system - dwarf planets.