Download S NOTES Astronomy

Name____________________________
NOTES Ch 8 ASTRONOMY
Date______________
Observations that need to be explained:
a) The Sun _____________________ and _______________________ every
day
b) The Sun Rises in ______________ and sets in the ______________________.
c) The Sun’s path in the sky is an ________________________
d) The Sun is at different angular altitudes in the sky at different times.
e) The sun is ____________________________ directly above (at zenith) in
NY.
1) The _____________________________
theory (Earth centered) explains all of these
phenomena. Since movement of the Earth
cannot be felt early, scientists thought that
the Earth was stationary and everything else
moved around us.
a) The geocentric theory says that
the
Earth is at the center of the solar
system/universe.
But the Geocentric Theory does not explain this:
b) Foucault _____________________: a __________________ pendulum
provided the first good evidence of the earth’s rotation. The pendulum would continue to
swing in the same direction while the Earth rotated beneath it. A more recent source of
evidence of rotation is the swirling pattern of weather systems seen by satellites.
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c) The ______________________ Effect makes the Foucault Pendulum work.
The rotation of the Earth puts a "spin" on the air movement, which causes a curve in the
travel direction. In the Northern Hemisphere the turn is towards the object’s right.
(REVIEW)
d) Galileo disproved the geocentric theory. He was the first to turn the telescope
to the sky (he did not invent the telescope) for the purposes of scientific observations.
The moons of Jupiter orbit an object other than Earth. Galileo noticed that the four visible
moons of Jupiter appeared to orbit around Jupiter and therefore did not revolve around
the Earth. Galileo also observed the "phases of Venus" which demonstrated that Venus
orbited around the sun.
2) The ______________________________
Theory (Sun centered) explains all
observations made from Earth.
Rotation- _______________________________________________________________
1) The Earth rotates on its axis to give us night and day
a) How long does it take the Earth to spin once?
b) How many degrees is a full spin?
c) How many degrees per hour does the Earth move?
2) The Earth’s Rotation does not have the same speed all over
a) At the equator, rotation is 40,074 km/day or 1670 km/hr
b) At NY 31,200 km/day or 1300 km/hr
c) At the poles 0 km/day or 0 km/hr
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Revolution- _____________________________________________________________
1) The Earth revolves around the sun in _____________________ days
2) The ___________________ of ____________________is the imaginary line that the
Earth turns about. The axis always points to the North Star. This is called Parallelism of
the Earth's axis. The imaginary surface of the Earth's yearly trip around the sun is the
Plane of Earth's Orbit.
!Warning! The following statement sounds crazy but you'll understand it if you read it
slowly (or at least go back and re-read the last few lines)!
"The axis is tilted by 23.5° from the perpendicular to the plane of its orbit."
What if the tilt was different?
Less Tilt
If there was less of a tilt, the seasons would even out into a perpetual spring as the tilt gets closer to straight up and
down. All latitudes will get closer to 12 hours of day and 12 hours of night.
More Tilt
As the poles tilt further away from the perpendicular, the seasons would get more extreme. Summers get hotter and
Winters get colder. The time difference between day and night will get further out of balance.
Kepler’s Law
1) All planets travel in elliptical orbits with the sun at one focus.
Note: The Earth's orbit is so close to a perfect circle that it can't be distinguished with the
human eye.
Here's a highly exaggerated drawing of Earth's
Elliptical orbit:
Although we may be closer towards the Sun by
3 million miles in January, the Northern
hemisphere is tilted away so we still feel colder
temperatures.
2) An __________________ is defined as 2 fixed points called foci or a focus that lie
equal distance from the midpoint of the major axis; a line down the longest length of the
ellipse.
a) The __________________ __________________ the foci are makes the
ellipse more flattened and gives it a higher eccentricity (how far from being a
circle an object is) ESRT pg 1 and 15
b) The closer together the foci, the more __________________________ the
object is, making it have NO eccentricity or 0.
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The Moon
1) The moon ______________________________around the Earth once a month
a) The moon rises 50 minutes later every day and can be seen during the day just
about as much as the night.
Eclipses - means "gets dark."
Lunar
Solar
1) A lunar eclipse occurs when the Earth blocks out the ___________ sunlight. The
moon "gets dark" as it goes into the Earth's shadow. Lunar eclipses happen during a Full
Moon.
2) A solar eclipse is when the ________________ "gets dark" because the moon blocks
sunlight from reaching the Earth. Solar Eclipses happen during a New Moon.
a) Eclipses do not occur every time there is a full or new moon, because the
moon's orbit around the Earth is inclined.
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Tides
1) The _______________________ of _____________________ depends on how close
two objects are and their masses.
a) A ______________ tide is caused by a full
moon and a new moon. The water “springs”
from its highest level to it’s lowest for the
month.
b) A _______________ tide is caused
by the half moon phases. The high
tide is not so high and the low is not
so low.
Comets - Chunk of ___________and__________
following an elongated elliptical orbit.
1) Comets have a ________________ only
when they come close to the sun and it
heats up and melts. Then the solar winds
sweep the tail away, which is why the tail
always points away from the sun.
Meteors
1) _________________ Showers mainly result
from debris created by the orbit of a comet.
a) If the Earth crosses the path of the comet, the debris will fall to Earth as a
visible meteor or “shooting star.”
b) If the rock is big enough and survives the _________________ entry into the
atmosphere it will hit the surface as a meteorite.
Asteroids
1) They are located mainly in the Asteroid belt, between _________________ and
Jupiter.
a) 66 million years ago an asteroid _____________________ could have been
responsible for why the dinosaurs became extinct. Evidence of the impact is a
thin layer of Iridium dust that covers the Earth geologic record.
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b) The dust covered the atmosphere, blocking ___________________________,
cooling the climate and making food scarce.
Stars
1) As the Earth turns ____________________________________, the stars appear to
move across the sky in large arcs with the North Star at the middle of the arc. If a camera
was left open for several hours, the stars will create streaks in the picture forming a bullseye around the North Star.
2) The stars that make a __________________ ___________________ without going
below the horizon are called circumpolar stars and are part of circumpolar
constellations. These stars are visible all night, every night of the year. In NY the Big
Dipper is one of a few such circumpolar constellations.
Galaxies- a huge body of _________________ that are gravitationally bound to each
other
1) We are in the ______________ ____________ galaxy, made of about 100 billion
stars
a) The Sun, other stars and the planets are on one of the _______________ arms.
b) The next nearest galaxy is the Andromeda galaxy, which is about 2 million
light years away (1 light year = 9.5 x 10 15 meters) and one of about 30
galaxies in our local group of galaxies.
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Stellar Fusion
1) Stars get their energy by converting
__________ into energy. According to Einstein's
famous equation (E=MC2) the amount of energy
(E) equals the mass of the matter converted (M)
times the speed of light squared (C2). As a result,
a small amount of matter will give off a
tremendous amount of energy.
2) Stars are fueled by ___________
___________, which is a process of taking small
atoms and fusing them together into larger atoms.
During the
process, some of the matter is converted into
energy.
The Life of a Star (ESRT pg 15)
1) The star begins as a _____________ of _____________ in space. Due to gravity of
every atom in the gas, the cloud will contract. As it contracts, it heats up.
a) When the heat gets intense enough, atoms will begin the process of ________.
The star is born and will continue to fuse its atoms until it runs out of fuel. At this
point the star can go on two different paths depending on the size of the star
If the star is like the sun or smaller
If the star is like the sun or larger
Swell up to a red giant – very

big





and bright
Shrink to a white dwarf- very
hot, but dim and small

Slowly cool and die
Swell up to a red supergiant
Shrink collapse and explode as a
supernova
Dies as a rapidly spinning core
Or better yet... A black hole!
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Doppler Effect
1) The Visible Spectrum- _________________ _____________________ splits into
the colors of the rainbow when passed through a prism. (ESRT pg 14)
2) When an element is ____________________, it gives off light. As seen through a
prism, the light will split into the basic colors that make that light (just like the rainbow).
Each element has its own unique light with its own pattern of colors sometimes called the
“fingerprint” of an element.
A
B
A) When a stationary object makes sound,
B) When the
sound moves towards
you hear a certain FREQUENCY. If you
you, it sounds higher in pitch and
could see it, it would look like this...
would look like this…
a) The faster the object moves, the _________________ the pitch. When the
sound moves away, it sounds lower. The same shifting happens with the light
from a moving star.
b) When the star is moving ___________ the spectrum shifts to the
___________ end of the rainbow or a shortening of its wavelength, an
increase in its frequency.
c) Since the universe is expanding, all distant objects have a ____________
shift. The farther the object, the more extreme the red shift.
d) Astronomers use this relationship between distance and speed to measure the
distance to distant stars and galaxies.
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The Planets (ESRT pg 15)
1) Rocky terrestrial planets are ________________________, Venus, Earth and Mars
a) They are all _______________, with high ___________________________
b) Venus is ______________________ than Mercury even though Mercury is
closer to the Sun. This is because Venus has a _____________________ layer of
greenhouse gases and can easily trap heat energy.
2) Gas Giants are Jupiter, Saturn, Uranus and ___________________________
a) They are made up of compressed ____________ with tiny solid or liquid
cores.
b) They are all about 4-11 times the diameter of the Earth.
c) Saturn is the only planet whose density is LOWER than waters (1g/cm3), so if
we could get an ocean large enough to put Saturn in, it would float.
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