Transcript Astronomy_in_space_powerpoint Fall 2016

Astronomy
Earth in Space
astro.washington.edu
Key Vocabulary
•
•
•
•
•
•
•
•
•
•
•
Aphelion
Axis
Barycenter
Big Bang
ellipse
Galaxy
Galaxy cluster
Local cluster
Milky Way galaxy
Nuclear fusion
Nutation
•
•
•
•
•
•
•
•
•
•
•
Perihelion
Precession
Revolution
Rotation
Solar System
summer solstice
vernal equinox
winter solstice
*compare
*contrast
*describe
What do you know about the universe?
• http://www.youtube.co`m/watch?v=Zr7wNQw12l8
• http://www.youtube.com/watch?v=7_2Ts0JpB-M
The Universe
•
•
•
•
Houses all existence
Is growing larger
Contains billions of galaxies
http://www.esa.int/esaKIDSen/SEMX4EBE8JG_Our
Universe_0.html
• From the largest to the smallest:
Universe -> galaxy clusters -> galaxies -> stars with
planets (solar systems) or stars (without planets) ->
individual planets (like Earth)
Galactic Address
Universe ->
galaxy clusters ->
galaxies ->
stars with planets or
stars (without planets) ->
individual planets (like
Earth)
Universe
Local Group (28 galaxies)
Milky Way galaxy
Solar System with the Sun
Earth
Size Representations
Galaxy Cluster
Individual Galaxy
The Milky Way Galaxy
-Where we live
I have at least
3 spiral arms.
My center is
about
100,000 light
years wide. I
am a spiral
galaxy
Star Systems and Individual
Stars
Star with a solar system
-the star looks different here because
you are zoomed out to see the planets
Star (Hubble Telescope)
-close ups of individual stars
Our Solar System
Earth
Quick Check 1
1. What galaxy do you live in?
2. What is the name of the star that accompanies our
solar system?
3. Do all stars have planets?
4. When galaxies are grouped together, what do they
form?
How did the universe form?
Big Bang Theory
Read p. 720
As your read: answer
1. How long ago did the universe form
according to the Big Bang?
2. What direction did matter move?
3. What was created when the dense,
hot, super massive ball exploded?(2
things)
4. Visual: How long after the universe
began did the first stars and galaxies
begin to form?
5. Honors: Name 2 types of evidence
used to support the theory.
http://www.esa.int/esaKIDSen/SEMSZ5W
JD1E_OurUniverse_0.html
http://www.geekologie.com/2009/08/int
eresting-video-explaining-t.phpp
What
happened?
We are
moving
away rom
each
other!
Big Bang
Super hot, massive dense ball 
its material began to move outward in
all directions
No new atoms
have formed
since this time.
universe began
Talk about
recycling!
universe began to cool
atoms formed
stars and galaxies formed
they continue to move outward
Balloon Lab
Make sure you complete the task and
answer the questions! Answers must
be turned in to the basket on the blue
book shelf!
Will the universe keep on growing?
Open Universe
• It depends on its average
density: it just may continue to
grow forever
• Scientists currently believe this
will happen!
Big Crunch
• Will occur if average density
gets to high
• Galaxies will begin to move
outward less quickly until they
stop
• A gravitational contraction
would occur
• The galaxies would collide and
form a high density mass
Compare and Contrast the Big Bang
and the Big Crunch using a VennDiagram
Solar System Formation: Nebular
Hypothesis
• Rotating cloud of gas(hydrogen
and helium) and dust called the
nebulacollapses into the
centerheat is generated
protosun formednuclear
fusion began @ 10 million
degrees Kelvinsun
formednebula began to cool
and solids formsolids make
ringsparticles in rings collide
forming planets
• Heavier materials made 4 inner
planets, lighter materials and
gases made 4 outer planets
Nebular Hypothesis
• Our solar system formed
about 4.6 million years ago
Earth: A Unique Planet
A. Earth’s Shape
1. appears to be a perfect sphere from
outer space
2. circumference(distance around) varies
a. 40 007km around the poles
b. 40 074 around the equator
*equator = an imaginary line that divides
the earth into Southern and Northern
Hemispheres
3. Oblate spheroid(slightly flattened
sphere)
40007km
40074 km
A person would not
have to have as
much gas to travel
around the poles (if
they were able to
drive the same type
of vehicle.
Earth’s Gravity
•
•
•
•
•
Gravity is the force of attraction that
exists between all matter in the
universe
The amount of the force depends on
the mass of the objects and the
distance between them
larger the mass of 2 objects, =
greater force of gravity
Causes Earth to go around the sun
Causes the sun to be pulled towards
the center of the Milky Way Galaxy
greenstonepatent.com
scienceuniverse101.blogspot.com
Barycentre(barycenter)
• Barycentre: the center of
mass or the point between 2
objects where they balance
each other
– In our solar system: Planet and
the sun orbit around the center
of the mass(Barycenter)
– http://spaceplace.nasa.gov/bar
ycenter/
– Used for planet hunting: when
a star and a planet have a
common barycentre the star
wobbles; thus, a wobbling star
indicates a planet
www.youtube.com/watch?v=CnLwLF4e6uQ
Kepler's First Law of Motion
• Describes shape
• A planet does not travel
around the sun in a
perfect circle; it travels in
an oval shaped pattern
called an
ellipse(sometimes called
an elliptical pathway)
• The sun is at one of the
focus points; it is not
directly in the center
http://howthingsfly.si.edu/flightdynamics/kepler%E2%80%99s-laws-orbitalmotion
I look like a
flattened pancake!
Earth is moving at a speed of
107 000km/hr
Kepler’s Second Law of Motion
• describes the speed at which
any given planet will move
while orbiting the sun
• The line joining the planet to
the Sun sweeps out equal
areas in equal intervals of
time
• Speed of planet changes
– Moves the fastest: closest to
the sun
– Moves the slowest: farther
from the sun
– http://www.physicsclassroom.c
om/mmedia/circmot/ksl.cfm
Kepler’s Third Law of Motion
• compares the orbital period
and radius of orbit of a
planet to those of other
planets
• the period for a planet to
orbit the Sun increases
rapidly with the radius of its
orbit
It is a
mathematical
comparison!
Investigation: Gravity and Orbits
Background:
1. A moving body tends to move in a straight line at constant
speed unless some outside force acts on it.
2. Gravity is the outside force that acts on satellites and
keeps them in orbit around the earth.
3. Earth orbits the sun in a counter clockwise motion. Earth
rotates in a counterclockwise motion.
Purpose: To model the effect of gravity on a moving body.
Materials: bowl, bead, paper, pencil
Investigation: Gravity and Orbits
1. Place the bowl face down in the center of the paper and trace a circle around it.
2. Mark 4 points at equal distances around the circle. (Mark at the 12, 3, 6,and 9
o’clock position.)
3. Number the points 1,2,3,4.
4. Place the marble in the circle. Place the bowl upside down over it.
5. Slowly swirling bowl in a clockwise until the marble rolls smoothly along the rim of
the bowl; get the bead spinning around the rim of the bowl.
6. Stop swirling the bowl as the marble approaches #1, then quickly lift the bowl,
allowing the marble to escape.
7. Observe and record its path. Draw the entire pathway on your paper and label it #1.
8. Repeat 4-6 and stop at position 2. Draw the entire pathway on your paper and label
it #2.
9. Repeat 4-6 and stop at position 3. Draw the entire pathway on your paper and label
it #3.
10. Repeat 4-6 and stop at position 4. Draw the entire pathway on your paper and
label it #4.
Investigation: Gravity and Orbits
1. A. What path does the marble take when the
hoop is removed?
B. Is the pattern of the path the same for all exit
points?
2. In what direction does the rim of the bowl push
the marble?
3. What force does the rim of the bowl represent?
4. Compare the motion of the marble to that of a
satellite around earth. Be sure to include how
they are alike and how they are different.
Earth’s Motion: Rotation
•
Earth spins around its
imaginary axis in a
counterclockwise direction
• Creates night and day
--Solar day: 24 hours in time
--Sidereal day : 23 hours 56
min and 4 sec
• Causes Coriolis effect(wind
appears to be
turned/deflected)
• Sun appears to rise in the east
in the morning and sets in the
west
• Earth’s shape(bulging center)
astro.cornell.edu
Earth’s Motion
Revolution(orbit)
• defined as the motion of a body
along a path around some point
in space
• The movement of Earth in its
orbit around the sun in an
elliptical pathway
aphelion
perihelion
snyder7hills.
org
– causes the sun to appear to be
displaced about 1 degree daily
– Perihelion: January 3: Earth is
closest to the sun(147 million km)
– Aphelion: July 4: Earth is farthest
from the sun(152 million km)
• moon revolves around Earth
Sun should not be
in center
Earth’s Motion: Precession
D. Precession
1. result of forces acting
on a spinning body
*gravitational force on
rotating Earth by the
moon, sun, other planets
2. causing earth’s axis to
move in an ellipse(takes
26, 000 years)
* Axis presently points
towards Polaris in the year
14 000 it will point towards
Vega
oceanworld.tamu.edu
Earth’s Motion
Note the direction of the tilt of Earth in
the revolution of each picture.
Earth’s Motion: Nutation
E. Nutation = wobbling around
the processional axis (This is
a change in the angle—½
degree one way or the
other.)
1. occurs over an 18 year
period
2. due to the Moon
exclusively.
3. very slightly increase or
decrease the amount of
seasonal effects
More Motion
F. Earth moves with the solar
system towards Vega at
20km/sec.
G. Sun revolves around the
galaxy 250 000 km/sec:
230 million year trip.
H. Galaxies( group of stars,
gas, dust held together by
gravity) are moving
outward. As their distance
increases, their speed
increases.