Download ch 23 Touring our Solar System

Ch 23 Touring Our Solar
System
23.1 The Solar System
23.2 The Terrestrial Planet
23.3 The Outer Planets
23.4 Minor Members of the Solar System
Ch 23.1 The Solar System
!   Terrestrial planets!   Mercury
!   Venus
!   Earth
!   Mars
Small Rocky Dense
!   Jovian Planets- Huge gas giants
!   Jupiter
!   Saturn
!   Uranus
!   Neptune
!   Size is the biggest difference between Terrestrial and Jovian.
!   Chemical make-up and also rate of rotation are other ways
the two groups of planets differ
Ch 23.1 The Solar System
!   Interiors of the planets
!   Terrestrial-Rocky and Metallic with
minimal gases
!   Jovian- Large amounts of gas (Water,
Ammonia, and methane) with minimal
amounts of metals
!   Atmospheres of the planets
!   Terrestrial- Small, thin atmosphere from
less gravity
!   Jovian- Thick atmosphere of hydrogen,
helium, methane and ammonia
Formation of the Solar System
!   A cloud of dust and gas in space is called a nebula.
!   These this gaseous clouds begin to rotate slowly and
contract gravitationally.
!   Nebular Theory – The sun and planets formed from a
rotating disk of dus and gases.
!   As the speed of rotation increased, the disk flattened
out.
!   Planetesimals – colliding matter around the center of
the disk, eventually formed the planets.
Nebula Theory
23.2 The Terrestrial Planets
!   Mercury- The innermost planet, 2nd
smallest, barely bigger than our moon
!   Does not reflect (6%) majority of light
since it has no atmosphere
!   Has many ridges from cooling and
shrinking
!   One day on Mercury takes 59 Earth
days
23.2 The Terrestrial Planets
!   Venus- Earths twin; Similar size, mass
and density
!   Second brightest object in the night
sky
!   Hottest planet in our solar system
!   Radar reports indicate a very active
surface from volcanoes and tectonic
activities
!   Over 1500 giant volcanoes
!   Over 475oC from greenhouse effect
!   Atmosphere is 97% Carbon Dioxide
(Holds Heat)
23.2 The Terrestrial
Planets
!   Mars- The Red planet, Easiest planet to
see from Earth
!   Atmosphere is very thin, but still
extensive dust storms occur which lead to
color changes on the planet ( 270 km/h)
!   No liquid water but frozen water covered
by solid carbon dioxide was sampled by
probes (Rovers Opportunity & Viking)
!   Many scientist believe evidence indicates
that Mars had a water cycle similar to
Earth
!   Jupiter-1/800 of the sun, Largest
planet by far, If 10 times as big it
would ignite into a star, 63
moons including the largest in
the solar system (Ganymede)
!   Jupiter has the mass that is 2.5
times greater than all other
planets and moons combined
!   Wind systems create dark and
light bands, one area called the
Red Spot is where a constant
cyclonic storm occurs
!   Has fine dust particles forming
rings which are thought to come
from meteorites hitting its
moons
23.3 The Outer
Planets
23.3 The Outer Planets
!   Saturn- 1 Saturn year is 29.46
Earth years, twice as far from
the sun at Jupiter but
chemically very similar, 31
moons
!   The most prominent feature
of Saturn is its system of
rings, broken into 4
categories rated on size of
particles
!   Has 2nd largest moon in the
solar system (Titan) which is
larger than Mercury
!   Uranus- Rotates on its
side or parallel with the
plane or orbit
!   Has a ring system of at
least 9 belts
!   Neptune- 13 moons,
Windiest place in all of
the solar system
!   Methane atmosphere
absorbs red light and
reflects blue light which is
why this planet looks blue
23.3 The Outer
Planets
23.3 The Outer Planets
!   Pluto
!   40 times farther away from the sun than the earth
!   Orbit is so skewed that it travels inside the orbit of Neptune in which
is resided from 1979 to Feb 1999
!   Its moon Charon has a diameter of over half its size which is
exceptional
!   Its size, composition leads scientists to the thoughts it shouldn’t be a
planet, but to not dishonor astronomical history and confuse the
public they have not officially changed it.
23.4 Minor Members of the Solar
System
!   Most Asteroids lie between the orbits of Mars and
Jupiter. Small, rocky bodies - “flying mountains.”
!   They have orbital periods of 3-6 years
!   Comets are pieces of rocky and metallic materials
held together by frozen gases, such as water,
ammonia, methane, carbon dioxide, and carbon
monoxide
!   As comets approach the sun they start evaporating
the frozen gases and creates a glowing head called a
Coma
!   Tails of a comet are always pointed away from the
sun
!  
23.4 Minor Members of the Solar
System
A Meteor is a small solid
particle that travels
through space, enters
our atmosphere and
burns up
!   Shooting star, Meteor
Shower
!   Small solid particles that
do not enter our
atmosphere are called
Meteoroids.
!   A meteoroid that actually
reaches Earth s surface
is called a Meteorite
23.4 Minor Members of the
Solar System
!   Most meteoroids originate from any one of the following three
source
!   1) Interplanetary debris that was not gravitationally swept up
by the planets during the formation of the solar system
!   2) Materials from the Asteroid Belt
!   3) The solid remains of comets that once traveled near Earths
orbit
23.4 Minor Members of the
Solar System
!   Scientists used evidence from meteorites, moon rocks, and
Earth rocks to determine the age of the solar system.
!   Radiometric dating shows that the oldest meteorites formed
more than 4.5 billion years ago.
!   Moon rocks have been dated to about 4.6 billion years.
!   The oldest rocks found on Earth are 4 billion years old.