Download Chapter 7 - SFA Physics and Astronomy

Chapter 6
The Solar System
Planet Comparisons
Property
Terrestrial Planets
Jovian Planets
Distance
from the Sun
Close
Far
Size
Small
Large
Mass
Small
Large
Composition
Rocky
Solar-like
Density
High
Low
Relative Sizes
JUPITER
1
2
3
4
5
6
7
8
9
10
Earths
11 Earths can fit across
Jupiter’s equator.
11
Formation of the Solar System

The solar system formed from a cloud of
gas and dust in a process known as
accretion.

During the first few million years, matter in
the accretion disk of our proto-sun
coalesced into larger objects called
planetesimals, with diameters of about
100 km.
Some resources compliments of
Mcgraw-Hill
http://www.dushkin.com/powerweb
Username: astro
Password: mars
We see evidence of
accretion disk
around other stars.
 For example,
b Pictoris.
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Collisions of planetesimals dominated the
early solar system and these objects
combined to form our planets.

We see evidence of early collisions in our
solar system in the form of impact craters
on the planets and their moons.

In addition to the 9 major planets, there are
at least 65 moons in our solar system.
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While some of these moons are spherical,
most look roughly like potatoes.

There is still minor debris left over from the
formation of the solar system: asteroids
and comets.
Bode’s Law

a simple rule that gives the distances of the
planets from the Sun
N 4
Orbit Radius of a Planet  RN 
AU
10
where N=0, 3, 6, 12, 24…for Mercury, Venus,
Earth, Mars, etc.
Planet
N
Bode’s Law Radii
Mercury
0
(0+4)/10 = 0.4 AU
0.39 AU
Venus
3
(3+4)/10 = 0.7 AU
0.72 AU
Earth
6
(6+4)/10 = 1.0 AU
1.00 AU
Mars
12
(12+4)/10 = 1.6 AU
1.52 AU
____
Ceres
Jupiter
24
48
(24+4)/10 = 2.8 AU
(48+4)/10 = 5.2 AU
_______
2.88 AU
5.2 AU
Saturn
96
(96+4)/10 = 10.0 AU
9.5 AU
Uranus
192
(192+4)/10 = 19.6 AU19.2 AU
Neptune
?
Pluto
384
?
True Orbital Radii
30.1 AU
(384+4)/10 = 38.8 AU39.5 AU
What does Bode’s Law tell us?

Bode's Law predicted that there should be a
planet between the orbits of Mars and
Jupiter.

The "missing planet" turned out to be the
asteroid belt.
Arizona Meteor Crater
Approximately 1 mile across
Arizona Meteor crater superimposed
over a map of NYC
Odessa,
Texas
500 ft wide
Exploration of the Solar System
Mariner Missions
1973- 1975 Exploration of Mercury and
Venus
Probe
Mariner 4 (1965)
Mariner 10 (1973-1975)
Mission
Mars
Mercury
Mariner 6&7 (1969)
Mariner 9 (1971)
Viking 1&2 (1976- 1982)
Mars Observer (1993)
Mars Global Surveyor ( 1996)
Pathfinder/Sojourner (1998)
Pioneer & Voyager (1970s)
Galileo (1989)
Mars
Mars
Mars
Mars
Mars
Mars
Jovian Planets
Jupiter
The Viking Lander – Mojave Desert
prior to launch
View of the Martian Surface by
Viking I
More recently, the Mars rover
“Sojourner” analyzes a Martian
rock in 1997.
Voyager Missions –Explore the Outer Planets
Photograph of Jupiter’s Red spot taken by Voyager I
Galileo was another probe that
studied Juipiter extensively.
Go To videos –
Galileo flybys from
JLP
Planets
outside of our
solar system have been
found recently using
Doppler shifts in the
spectra of some stars.
End of Section.
The End.
Matching
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1. Reddish color of Mars
2. Red-orange color of Jupiter's belts
3. Venus' yellowish clouds
4. Blue-green color of the surface of
Uranus and Neptune
5. The yellow and orange color of Io

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a.
b.
c.
d.
e.
ammonia clouds
sulfur powder
sulfuric acid clouds
methane clouds
iron
Matching
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6. Has an almost featureless surface
7. The brightest planet seen from Earth
8. The most distant planet in 1996
9. Last planet in our solar system to be discovered
10. A possible fossil of single-cell life was found
on a meteorite from this planet

a. Sun

b. Mercury

c. Venus
d. Earth
e. Mars
f. Jupiter
g. Saturn
h. Uranus
i. Neptune
j. Pluto
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