Our Solar SystemOur Solar System

Our Solar SystemOur Solar System

Consists of the sun, eight planets, their moons, asteroids, comets, and

The planets are all unique and differ in terms of their:– Size– Surface temperature– Chemical elements (e.g. H, He, O2 and C)– Gravitational field strength (surface gravity)

The Inner (Terrestrial) PlanetsThe Inner (Terrestrial) Planets

The four planets closest to the sun

Mercury Venus Earth Mars

They are:– Small– High density– Mainly composed of rocks/metals

The Outer Planets or Gas GiantsThe Outer Planets or Gas Giants The four planets farthest from the sun

Jupiter Saturn Uranus Neptune

They are:– Large– Low density– Mainly composed of gases such as hydrogen and helium

PlutoPluto**Pluto is in a category by itself. Due to

its strange orbit and tiny size it is no longer classified as a planet. It has been re-classified as a minor or dwarf planet.

Other Objects in our Solar SystemOther Objects in our Solar SystemAsteroids (aka:Minor Planets)

– Small rocky objects– There is a ring of asteroids between Mars and

Jupiter known as the “Asteroid Belt”

CometsComets

Aka “Dirty Snowballs”

Made up mainly of dust and ice

Travel in a very long orbit around the Sun

CometsComets

As the comet approaches the Sun, it is warmed. Frozen material begins to melt and then evaporate from its surface becoming gases. These gases are pushed outward by the solar wind to produce a bright tail.

A comet’s tail can be MILLIONS of kilometers long and always points away from the Sun.

http://www.windows2universe.org/comets/comet_model_interactive.html

Meteors (aka Shooting Stars)Meteors (aka Shooting Stars) A meteoroid is a small

rock or particle of debris in our solar system. They range in size from dust to around 10 metres in diameter (larger objects are usually referred to as asteroids).

A meteoroid that burns up as it passes through the Earth’s atmosphere is known as a meteor.

Most never reach the earth. http://www.youtube.com/watch?v=D8DPrVSmjwI

..\..\..\My Videos\grade nine science\Spaced Out- Meteors, Meteorites and Shooting Stars.mp4

MeteoritesMeteoritesA meteor that

hits the Earth before it completely burns up.

Produce large craters

http://www.youtube.com/watch?v=dBvotWfR3j4

..\..\..\My Videos\grade nine science\Meteorite Explosion - Russia Chelyabinsk 2_15_2013 - Asteroid expected to pass close by Earth.mp4

Planetary Moons Planetary Moons (aka. Natural Satellites)(aka. Natural Satellites)

Large natural objects that revolve around the planets

Each moon is a different size and has a different surface

Contain useful minerals

Luminous vs. non-luminousLuminous vs. non-luminous

Luminous objects are seen because they give off their own light. Examples are stars.

Non-luminous means objects can only be seen because light from the sun reflects off of them. Examples are planets, moons, asteroids and comets.

HomeworkHomework

Read pg 430 433Questions p. 433 # 3 - 5