Transcript Solar System

Unit 2: The Solar System
The Big Idea:
Planets and a variety of other
bodies form a system of objects
orbiting the sun.
Unit 2 Lesson 1 Historical Models of the Solar System
The Center of the Solar System
• Solar system - the sun & all of the
bodies that orbit the sun.
• Heliocentric model – Sun centered,
Earth and the other planets orbit the
sun.
• Geocentric model – Earth centered,
the sun, moon and planets circling the
Earth
Unit 2 Lesson 1 Historical Models of the Solar System
In the beginning…
Aristotle (384-322 BCE)believed in a geocentric
model, part of his logic was
that we could feel no motion
on Earth, so Earth couldn’t be
moving. He thought we should
detect a shift in position
between nearby stars and far
away ones.
•
Parallax- apparent shift in
the position of an object
when viewed from different
locations.
Unit 2 Lesson 1 Historical Models of the Solar System
 Aristarchus (about 320 230 BCE)-
proposed a heliocentric model, his
attempts to measure relative distances to
moon & sun have been major contribution
to science
http://www.astro.cornell.edu/academics/courses/astro2201/aristarchus.htm
Ptolemy- (100-170 CE) believed in a
geocentric model.
His model was used for 14
centuries.
• Planets moved on small
circles that in turn moved
on larger circles
(“wheels-on-wheels”)
• Allowed people to predict
the motions of planets
years into the future.
•
Unit 2 Lesson 1 Historical Models of the Solar System
Unit 2 Lesson 1 Historical Models of the Solar System
Copernicus- (1473-1543) believed in a
heliocentric model with perfect circles
Kepler- (1571-1630)
Realized that
planetary orbits were
not circular but were
more like ellipses.
Unit 2 Lesson 1 Historical Models of the Solar System
Galileo Galilei (1564-1642)
 Improved the telescope
in 1609
 Observed Jupiter’s
moons, Io, Europa,
Callisto, and Ganymede
which gave support of
heliocentric model
 Observed Venus’s phases
Unit 2 Lesson 2 Gravity & the Solar System
 Gravity - force of
attraction between
objects that is due to
their masses & the
distances between them.
 Every object in the
universe pulls on every
other object.
 Orbit - path that a body
follows as it travels around
another body in space.
http://kissedgoodbye.blogspot.com/2012/01/gravity.html
Inertia: tendency
of an object to
resist any change in
its motion.
Unit 2 Lesson 2 Gravity & the Solar System
Kepler’s Three Laws
1. Planetary orbits are ellipses with the sun at one
focus
Aphelion- where the object is farthest from the sun.
Perihelion - where the object is closest to the sun.
2. Planets move faster in their orbits when they are
closer to the sun.
3. Distance of a planet from the sun to the time the
planet takes to go once around its orbit.
Unit 2 Lesson 2 Gravity & the Solar System
Law of Gravitational Force
Law of universal
gravitation- states that all
objects in the universe
attract each other through
gravitational force.
• Centripetal force -inward
force that causes an object to
move in a circular path.
http://www2.nido.cl/~science/ksupplee/Mechanics/circular%20m
otion/uniform%20circular%20motion.html

When planets orbit the sun, a force similar to centripetal force prevents them from
moving out of their orbits and into a straight line.

The sun’s gravity is the force that keeps the planets moving in orbit around the sun.
http://www.teachersdomain.org/resource/phy03.sci.phys.mfw.roller/
How the Solar System Formed Theory
Solar Nebula - inward pull of gravity is balanced by the
outward push of gas pressure in the cloud (perhaps the
explosion of a nearby star)
• Planetesimals - Collisions between these bodies
formed larger bodies from which planets formed
Unit 2 Lesson 3 The Sun
Here Comes the Sun
• Corona-outer
atmosphere of the
sun (up to 2,000,000 ˚C)
• Chromospheremiddle layer of sun’s
atmosphere (6,000 ˚C)
• Photosphere- visible
surface of the sun.
Energy escapes into
space (5,527 ˚C)
Unit 2 Lesson 3 The Sun
• Convective Zone – energy travels by
convection from the radiative zone to the
photosphere
• Radiative Zone - energy is transferred
away from the core by radiation.
Core – very dense
center of sun.
Temperature of
15,000,000 ˚ C, where
nuclear fusion occurs.
Unit 2 Lesson 3 The Sun
Solar Activity
Sunspots-dark
areas that form on
the surface of the
sun.
 Solar flare – an explosive release of energy
that can extend outward as far as the sun’s
outer atmosphere
 Prominence- huge loops of relatively cool
gas that extend outward from the
photosphere
Unit 2 Lesson 3 The Sun
Nuclear Fusion - process by which two or more lowmass atomic nuclei fuse to form another, heavier
nucleus.
Three Steps of Nuclear Fusion in the Sun
1. Deuterium - 2 H+ collide (1 P, 1 N- a heavy hydrogen)
2. Helium-3 – deuterium combines w/
another H+ (more energy/ gamma rays released)
3. Helium-4 – 2 He-3 nuclei combine to
form He-4 (more energy/pair of H+ released)
turn to pgs 78-79
http://www.physics.arizona.edu/~thews/reu/the_science_behind_it_all.html
Unit 2 Lesson 3 The Sun
Mixing It Up
 Radiation: energy leaves the core in the
form of electromagnetic waves;
movement of heat waves.
 Convection:currents are created when
there are differences in temperature &
density within a fluid.
 Conduction: transfer of energy (heat) by
direct contact between 2 materials with
different temperatures.
http://outreach.atnf.csiro.au/education/senior/astrophysics/stellarevolution_mainsequence.html
Unit 2 Lesson 4 The Terrestrial Planets
 Distance from sun: 0.39 AU
Mercury
 Moons: Zero
 Temp: -184˚C to 427˚C
 Name: Merurius by Romans b/c it appears to
move swiftly
 Rotation-last almost 59 Earth days
 Revolution-88 days
 Smallest planet with craters
http://www.bobthealien.co.uk/venus.htm
Venus
• Distance: 0.72 AU
• Moons: Zero
• Temp:(465 ˚C) CO2 traps the sun’s energy
•
•
•
•
•
•
Name: Roman goddess of love. Considered brightest
& most beautiful
Rotation- 243 Earth days
Revolution- 225 days
1000s of volcanoes & craters
Sulfuric acid rain
Retrograde rotation (clockwise)
Earth








Distance from sun: 1 AU
Moons: 1
Temp: -89˚C to 58 ˚C
Name: means “on the ground”
A planet that supports life
Liquid water, energy source
Atmosphere contains O2
Only planet divided into tectonic plates
Unit 2 Lesson 4 The Terrestrial Planets
Mars
•
•
•
•
•
•
•
•
•
Distance from sun: 1.52 AU
Moons: 2
Temp: -140˚C to 20 ˚C
Name: Roman god of war b/c its
red, bloodlike color
Rotation- 24 h 37 min
Revolution- 1.88 Earth years
Olympus Mons- largest volcano/mtn in solar
system
Valles Marineris – longest canyon in solar
system
Thin CO2 atmosphere
http://en.wikipedia.org/wiki/Mars_Exploration_Rover
Jupiter
 Distance from sun: 5.20 AU
 Moons: 63




Io-most volcanic
Europa
Callisto
Ganymede
 Temp: -150˚C
 Name: (Zeus by Greeks) Jupiter by Romans
was the most impt deity.
 Rotates fastest – 9 h 55 min
 Revolution– 11.86 Earth years
 Great Red Spot (large storm)
Unit 2 Lesson 5 The Gas Giant Planets
Saturn
• Distance from sun: 9.58 AU
• Moons: 60
• Rotation- 10 h 39 min
• Enceladus
• Revolution- 29.5 years
• Titan
• Planetary ring system
• Temp: -180˚C
+ & He
•
Made
of
H
• Name: Roman name for
Greek Kronos (father of
Jupiter)
• Farthest planet from Earth
that can be seen by the
naked eye
http://www.gearthblog.com/blog/archives/2006/04/google_jupiter.html
Uranus
• Distance from sun: 19.2 AU
• Moons: 27
• Miranda
• Temp: -210˚C
• Name: Greek deity of the sky, the father of





Kronos & grandfather or Jupiter
Rotation- 17 h 24 min
Revolution-84 years
Made of H+ & He
Atmosphere of methane
Tilted on its side as it orbits the sun
Unit 2 Lesson 5 The Gas Giant Planets
Neptune
• Distance from sun: 30.1 AU
• Moons: 13
• Triton-orbits opposite
• Temp: -220˚C
• Name: Roman god of the sea
• Rotation-16 h 7 min
• Revolution- 164.8 years
• H+/He and methane
• Great dark spot
http://www.bobthealien.co.uk/neptune.htm
Small Bodies in the Solar System
 dwarf planets- celestial body that orbits
the sun, is round because of its own
gravity.
 Ceres (between Mars & Jupiter)
 Pluto
 Haumea
 Makemake
 Eris
Kuiper Belt- orbits just beyond Neptune
 Kuiper belt object (KBO) -any of the
minor bodies in the Kuiper belt. They are
made of methane ice, ammonia ice, and
water ice.
Comets
 Comet -small body of ice, rock, & dust
that follows a highly elliptical orbit
around the sun.
 Oort cloud - spherical region that
surrounds the solar system
http://janus.astro.umd.edu/front/pages/links/Comets2.html
On the Rocks
 Asteroid – small, irregularly shaped,
rocky object that orbits the sun.
 Most located in the asteroid belt between
the orbits of Mars and Jupiter
 Some are rich in carbon, others rocky with cores
or iron and nickel
Burned Out
 Meteoroid -rocky body, ranging in size from
that of a sand grain to that of a boulder,
which travels through space.
 Meteor -bright streak of light that results
when a meteoroid burns up in Earth’s
atmosphere.
 Meteorite - a meteoroid that reaches
Earth’s surface without burning up.