CHAPTER 11
We continue to Learn a lot about the
Solar System by using Space
Exploration
Section 11.1
The Sun
page 390
-Average sized star
-300,000 more massive than
Earth, 99% of all mass in our
solar system
-Millions of km away
-Approx. 5 billion Years old
with 5 billion more to go!
The Huge size of the sun causes
pressure to build up at the center of
the sun as gravity pulls the mass
inward… Thermonuclear Reactions turn
H (hydrogen)
He (helium) giving
off Heat, Light and UV radiation in the
process
Heat, Light and UV radiation
H
He
Pressure
Solar Radiation – Energy (E) Emitted
from the sun in the form of
Electromagnetic Radiation
… E that is carried or radiated in
the form of waves that range in
length, ex. Microwaves, radio
waves, UV waves
The Earth is located in the “Goldilocks Zone”,
not too hot, not too cold, just right!
SUNSPOTS – dark patches of slightly
cooler (3500°C) surface areas on the
sun, they increase and decrease in
number on an 11-yr cycle. They may be
related to changes in the Earth’s
climate .
SOLAR FLARES – eruptions of
gas on the suns surface – can
last a few hours, temperatures
increase up to 11,000,000°C
Creates Solar Winds
Solar Wind
page 393
Hot E bubbles “pop” on the surface of the sun and send
high E particles rushing past Earth. Earth is protected
from this solar wind by its magnetic field. Some of the
particles enter the Earth’s atmosphere at the poles
where they collide with the gas in the atmosphere to
create Auroras (Northern/Southern lights) page 394.
Some solar winds can disturb
Earth’s magnetic field and disable
satellites, knock out power lines, and
expose astronauts to high levels of
radiation
Section 11.2
page 398
Characteristics of the Celestial Bodies
of the Solar System
The Planets
To be a planet you must…
 … orbit 1 or more stars
 … be large enough so its gravity
holds it in place
 … be the only body in its orbital
path
Astronomical Units (AU)
 Used to measure distances in space
1 AU = 150 million km
(the distance from the Earth to the Sun)
5.27 AU
1 AU
Activity 11-2A:
Terrestrial and Jovian Planets
Read Sectioon 11.2 of your text on the
planets and complete the table in your notes.
Mnemonic Device to Remember the order of the Planets???
Mercury, Venus, Earth, Mars, Jupiter,
Saturn, Uranus and Neptune
PLUTO
Now considered Dwarf Planet
– a celestial body orbiting the Sun that is
generally smaller than a planet but massive
enough for its own gravity to give it a round
shape. However they are not strong enough
to clear their orbit of debris
There are many other “dwarf planets” some
are bigger and some like Pluto have moons
A Comparison of 3 dwarf planets and
Earth, notice some have moons and some
don’t
COMETS
 “dirty snowballs” composed
of ice, rock and gas
 Originate from the Kuiper
Belt and Oort Cloud
 They travel in long elliptical orbits around the
sun which are affected by the gravitational
pulls of other planets
 It has a long dust tail as sunlight starts to
melt the ice, these can stretch millions of km
 Most famous Halley’s comet which is visable
every 76 years or so
Periodicity of Comets:
"Period" is the amount of time it takes an object in
orbit to return to its starting location.
Comets travel
in short and
long periods
around the
sun in elliptical
orbits
The elliptical orbit of Halley’s Comet
ASTEROIDS
 Small bodies believed to be the leftover remains of the
formation of the Solar System
 Mostly found in an asteroid belt between Mars and
Jupiter
 They have irregular shapes
 Range in size from a
grain of sand up to 1000km
 An asteroid up
to 1 km would devastate Earth
 Meteoroid – a rocky chunk,
METEORS
broken off an asteroid or
planet, which floats
through space
 Meteor – a meteoroid that
burns up as it passes
through Earths
atmosphere, seen as a
shooting star
 Meteorite – a meteoroid
that does not burn up fully
in the Earths atmosphere
and hits the Earths surface
Deep Impact Sites
 A place where a relatively small object (meteorite) has
collided with a larger object (planet)
 Produces a fairly circular depression in the surface of
the larger object referred to as an impact crater
QUIZ Thursday, October 17, 2013
10 True/False
15 Multiple Choice
6 Matching
2 Short Answer Questions
Study Guide:
•The Sun – characteristics, diagram, sunspots, solar flares, solar
winds, etc
•The Planets – characteristics, table of comparison for inner/outer
planets
•What is an astronomical unit?
•Pluto
•Comets
•Asteroids
•Meteors, meteoroid, meteorite
•Deep impact sites
•Worksheet for Section 11.3