Download Dwarf Planets

Unit 1
The Basics
Of Geography
Chapter 2, Section 1
The Earth
Inside and Out
Objectives
Describe the solar system and
the Earth’s location in it
Describe the Earth’s structure
and the forces that created it
The Milky Way
100 – 400
Billion Stars
50 Billion
Planets
The Milky
Way is one
of 200 Billion
galaxies in
the
observable
universe
(roughly 93 billion
light years)
The Solar System
Our solar system consists of:
 The Sun
 8 Planets
 Planetary Moons
 Comets
 Asteroids
 Dwarf Planets
The Sun
The Sun is a medium sized star on the edge of
the Milky Way galaxy.
109 times the size of the Earth
Accounts for 99.86% of the mass in the Solar
System
It takes 8 minutes and 19 seconds for light from
the Sun to reach the Earth
Planet
Definition*
a body that orbits the Sun, is large enough for its
own gravity to make it round, and has "cleared
its neighborhood" of smaller objects
* this definition only applies in our Solar System
The Eight Planets
Terrestrial Planets – primarily composed of
rock and metal
 Mercury, Venus, Earth, and Mars
Gas Giants – solid core surrounded by gases
such as hydrogen and helium
 Jupiter, Saturn, Uranus, and Neptune
PLANETS
Mercury
Distance from
the Sun
Mass*
Number of
Satellites
Rotation
Period*
Orbital
Period*
24 Hours
365 Days
36 M
Venus
67.2 M
Earth
93 M
Mars
141.6 M
Jupiter
483.6 M
Saturn
886.7 M
Uranus
1784 M
Neptune
2794.4 M
1
Comparison of the Planets and Stars
Comets and Asteroids
Comets – spheres covered with _____ and
________
Asteroid – large chunks of ______ material
Comets have a visible coma while asteroids do not
Dwarf Planets
Fits two of the three criterion to be a planet
Term was adopted in 2006
5 known dwarf planets
Pluto is the most well known dwarf planet
Eris is the largest recognized dwarf planet
Critical Thinking
1) Why is Pluto considered a Dwarf Planet?
2) Is it possible that there is life on other planets
outside our solar system?
Critical Thinking
1) Why is Pluto considered a Dwarf Planet?
2) Is it possible that there is life on other planets
outside our solar system?
Structure of the Earth
Inside the Earth
Core – center of the Earth;
made up of iron and nickel
Mantle – rock layer
between the core and the
crust


Several layers
Most of the Earth’s mass
Crust – thin layer of rock at
the Earth’s surface
On and Above the Earth
Atmosphere – layer of gases surrounding the
Earth
 protects Earth from radiation and space debris
 medium for weather and climate
Lithosphere – solid rock portion of the Earth's
surface
 includes the upper mantle and crust
 forms the sea floor under water
On and Above the Earth


Asthenosphere – layer of hot but mostly solid rock
below the lithosphere
Hydrosphere – all of the water elements on the
Earth



Oceans, seas, rivers, lake, etc
All the water in the atmosphere
Biosphere - atmosphere + lithosphere + hydrosphere
 Part of the Earth where plants and animals live
Geographic Thinking
How do the Earth’s spheres influence one another?