Download ASTRONOMY - Frost Middle School

There are 8 planets and a dwarf planet. The Sun is the center of our solar system:
MERCURY; VENUS; EARTH; MARS; JUPITER; SATURN; URANUS; NEPTUNE;
PLUTO
My Very Excellent Mother Just Served Us Nine Pizzas
MERCURY
• Smallest and fastest planet
• Orbit is 88 days
• Surface is rocky and covered
with craters
• Has no moon
VENUS
*Smaller than the Earth
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*Wrapped in bright clouds (greenhouse effect)
• Hottest Planet ; Temperatures 4640 C to 4800 C
• Air is poisonous to humans; contains CO2
• High pressure
• No moon
• Composition: Mostly rock
(Terrestrial)
EARTH
•The Earth is 93 million miles
(150 million km)
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The different layers of the Earth are: Crust, Mantle, Core
Orbits the Sun in 365 days (= 1 year)
Rotates in 24 hours (= 1 day)
One moon
LUNA
THE EARTH’S MOON
• Dry, dusty land, flat
plains, and craters
• Earth’s gravity keeps
the moon from going in a straight line
• The light of the moon is the reflection of the sun’s
light
• The dark side of the moon is the Earth’s shadow
PHASES OF THE MOON
• We always see the same side of the moon
• Revolution (orbit around the earth) is 27.3 days = 1 month
• The positions of the moon, sun, and Earth determine the phases of
the moon
ECLIPSES
• A lunar eclipse happens
when Earth comes between
the sun and the moon and
the shadow of Earth falls on the moon
• A solar eclipse happens when the moon comes between Earth
and the sun and the shadow of the moon falls on part of Earth
MARS
• Rocky and shaped by running water
• Looks red because the soil is rich in
rust (iron oxide)
• Same rotation as Earth (day)
• Revolution is twice as long as Earth (687 earth days)
• Has two small moons
• Mons Olympus is a volcano, 16 miles high
JUPITER
• A giant gas ball
• The planet of storms
• The Great Red Spot is a storm that
never changes and it is as big as 3 Earths
• Jupiter’s atmosphere consists of hydrogen, helium, some ammonia,
methane, and H2O
• Temperature of its interior can be 30,0000C
• High winds (540 km/h)
• Distance from sun 5,2 AU
• Rotation: 9h, 55 min
• Revolution: 11 years, 314 days
JUPITER’S MOONS
• Europa, Ganymede, Callisto, and Io are Jupiter’s largest moons
• Ganymede is the largest moon in the solar system
List of all Jupiter Moons (63):
1. Metis 2. Adrastea 3. Amalthea 4. Thebe 6. Europa 7. Ganymede
8. Callisto 9. Themisto 10. Leda 11. Himalia 12. Lysithea 13. Elara
14. S/2000 15. Carpo 16. S/2003 17. Euporie 18. S/2003 19. S/2003
20. Thelxinoe 21. Euanthe 22. Helike 23. Orthosie 24. 25. S/2003
26. Ananke 27. Praxidike 28. Harpalyke 29. Hermippe 30. Thyone
31. Mneme 32. S/2003 33. Aitne 34. Kale 35. Taygete 36. S/2003
37. Chaldene 38. S/2003 39. S/2003 40. S/2003 41. Erinome 42. Aoede 43.
Kallichore 44. Kalyke 45. Eurydome 46. S/2003 47. Pasithee
48. Cyllene 49. Eukelade 50. S/2003 51. Hegemone 52. Arche
53. Carme 54. Isonoe 55. S/2003 56. S/2003 57. Pasiphae 58. Callirrhoe 59. Sinope
60. Sponde 61. Autonoe 62. Megaclite 63. S/2003
SATURN
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800 times bigger than the Earth
Many moons (more than 53)
Titan is the largest moon of Saturn
Has rings
SATURN’S MOONS
• MAJOR MOONS (53 + 9):
Pan 1990; Atlas 1980; Prometheus 1980;
Pandora 1980; Epimetheus 1980; Janus 1966;
Mimas 1789; Enceladus 1789; Tethys 1684;
Telesto 1980; Calypso 1980; Dione 1684; Helene
1980; Rhea 1672; Titan 1655; Hyperion 1848;
Iapetus 1671; Phoebe 1898
• RINGS: A-Ring, B, C, D, E, F, G.
URANUS
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300 times bigger than the Earth
84 Earth years to orbit the sun
Strange thing: Orbits the sun on its side
Has rings
NEPTUNE
• 300 times larger than the Earth
• Two moons
• Jupiter, Saturn, Uranus, Neptune are called
OUTER PLANETS and GAS GIANTS
PLUTO
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Dwarf planet in Kueper Zone
Rock and ice
Charon is Pluto’s moon
Charon is the COLDEST place on the entire solar system
ASTEROID BELT
• Between the INNER PLANETS and the
OUTER PLANETS is the Asteroid Belt
• Full of asteroids that orbit the SUN
• ASTEROIDS are made of chunks of rock and some ice and
orbit the sun
GALAXIES
• Galaxies are identified based on their shape
• Clusters of billions of stars with different shapes:
spiral, elliptical, irregular
• Galaxies are composed of stars, star clusters,
nebulas, and planetary systems
• Classified by shape and by rate of star formation
• Spiral galaxies have
a bulge at the center and
spiral arms.
The Milky Way
• Our galaxy is a spiral shape
and is called the Milky Way
• Consists of about 200 billion
stars
• The sun is located about 2/3
of the way between the
center of the galaxy and the
galaxy’s edge
ELLIPTICAL GALAXIES
• Elliptical Galaxies are round or oval (cosmic snowballs)
• They have stopped making new stars more than 10 billion years
ago.
• They are the largest galaxies in the universe
• Contain up to 5 trillion stars
• They form by the merging of smaller galaxies
IRREGULAR GALAXIES
• Irregular galaxies are galaxies that have no definite shape
• Smallest ones have
only about 10 million stars
• Form new stars slowly
• Some form when galaxies
• collide
• The Milky Way is consuming a pair of nearby irregular galaxies
CONTENTS OF GALAXIES
• Galaxies contain stars, planetary systems, gas clouds and
star clusters
• Gas Clouds are called nebulas and they are large clouds of
gas and dust where stars are born
• Some nebulas glow, other types absorb light and hide stars,
and others reflect starlight
STAR CLUSTERS
• A globular cluster is a highly concentrated group of stars that
looks like a ball
• May have up to 1 million stars
• Open clusters are groups of 100 to 1,000 stars that are close
together relative to other stars
QUASARS
• Quasars are among the most distant objects in the
universe
• Star like sources of energy that are located in the centers
of galaxies
• They generate energy at a high rate and are among the
most powerful energy sources in the universe
• May be caused by massive black holes in the cores of
galaxies
• The quasar known as PKS 0637-752 radiates with the
power of 10 trillion suns
ORIGIN OF GALAXIES
• Scientists investigate the early universe by observing objects
that are extremely far away in space
• Because light takes time to travel through space, looking
through a telescope is like looking back in time
• Looking at distant galaxies
reveals what early galaxies
looked like
FORMATION OF THE UNIVERSE
The Big Bang Theory
• Most galaxies are moving away from each other
and the universe is expanding
• About 14 billion years ago, all of the contents of
the universe were compressed under
tremendous pressure, at high temperature and
high density, into an extremely small volume
• The universe was contracting and all matter
squeezed together in one small volume
• Then expanded and cooled
• Galaxy formation
FORMATION OF THE SOLAR SYSTEM
• The collision of particles formed
bodies the size of boulders and
asteroids
• As the mass of particles
increased, gravity increased
• Matter in the solar nebula was
pulled together by gravity into
spheres
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The solar nebula collapsed, rotated
Becomes hot and dense in its center
The gas and dust forms a disk
The disk begins to cool enough for dust
particles to form
• Particles begin to collide and form larger
particles
• Gravitational attraction pulls objects toward one another
• All objects experience gravity
• After the big bang, gravitational attraction caused the matter
distributed throughout the universe to form galaxies
• The mutual attraction between galaxies caused galaxies to cluster
• Even though the distances between galaxy clusters are very large, gravity
still acts between them
• Because gravity acts over such great distances, gravity controls the size
and shape of the universe
HOW OLD IS THE UNIVERSE?
• Astronomers can estimate the age of the universe by
studying white dwarfs, the oldest stars in the Milky
Way
• White dwarfs are the burned-out cores of stars that
started out with masses that were less than 8 times the
mass of the sun
• These stars have cores of carbon and oxygen at the end
of the red giant phase
• They lose their atmospheres in the planetary nebula
stage
• The planetary nebula stage is a stage in which the hot
central region of a star drives off the star’s cooler
atmosphere over a period of a few thousand years.
HOW OLD IS THE UNIVERSE?
• Once the star’s atmosphere is lost, all that is left
is the carbon-oxygen core- a white dwarf-which
is tiny, hot, and dense
• The oldest white dwarfs are 12 billion to 13
billion years old
• Because it took about 1 billion years after the big
bang for the first white
• dwarfs to form from the first
stars, the universe must be
approximately 14 billion years old
THE LIFE CYCLE OF STARS
• Stars can exist for billions of years
• Scientists study stars at different stages to
understand how they develop
• Stars are classified by mass, size,
brightness, color, temperature,
composition, and age
• Stars are different as they age
• The fast-expanding gas clouds
in the picture show a dying star
LIFE CYCLE OF SUNLIKE STARS
PROTOSTARS -1st Stage
• A star begins its life as a ball of gas and dust
• Gravity pulls the gas and dust into a sphere
• As the sphere becomes denser it gets hotter and
hotter to 10,000,000 in its center
• Hydrogen nuclei combine to become helium
• This is called nuclear fusion
• Causes energy to be released
LIFE CYCLE OF SUNLIKE STARS
MAIN-SEQUENCE STARS
• After it is formed, it enters the main sequence
• Second and longest stage of its life cycle
• Energy is generated in the core of the star as hydrogen atoms fuse
into helium atoms.
• Size changes very little
LIFE CYCLE OF SUNLIKE STARS
GIANTS AND SUPERGIANTS
• When a main-sequence star uses all of the hydrogen in its core,
helium begins to fuse
• The center of the star shrinks
• The atmosphere of the star grows very large and cools
• The star may become a red giant or
red supergiant ex. Betelgeuse
LIFE CYCLE OF SUNLIKE STARS
WHITE DWARFS
• In the final stage of its life cycle, a sunlike star becomes a
white dwarf
• Small, hot, and dim star that is the leftover center of a red
giant
• No longer generates energy by nuclear fusion
• Slowly cools and becomes smaller
• A white dwarf can shine for billions of years
H-R DIAGRAM
The Sun
*Middle age
*5 billion years old
Blue = Hot
Yellow = Medium
Red = Cool
THE AGING OF MASSIVE STARS
• Massive stars use their hydrogen much faster than stars like the
sun do
• More energy and they are very hot!
• Shorter lives
SUPERNOVAS
• At the end, a massive star may explode in a large, bright flash
called supernova
• A supernova is a gigantic explosion in which a massive star
collapses and its outer layers are blasted into space
THE AGING OF MASSIVE STARS
PULSARS -If a neutron star is spinning, it is
a pulsar
• Pulsars send out beams of
radiation that sweep across
space like a lighthouse over
the ocean
• Detected by radio telescopes
as pulses
called
THE AGING OF MASSIVE STARS
NEUTRON STARS
• The center of the supernova (collapsed star) may contract
into a very small but very dense ball of neutrons
• This ball of neutrons is called Neutron Star
• One teaspoon of matter from a neutron star would weigh 100
million metric tons of Earth
• A lot of energy (100,000 suns)
THE AGING OF MASSIVE STARS
BLACK HOLES
• An object so dense and massive that light cannot escape its
gravity
• If the center of a collapsed star has a mass several times the
mass of the sun, the star may contract more because of too
much gravity
• The force of the contraction crushes the dense center of the star
and leaves a black hole
BLACK HOLES
BLACK HOLES
BLACK HOLES
• Black holes do not give off light
• Locating them is difficult
• If a star is nearby, some gas or dust from the star will spiral into
the black hole and give off X rays
• These X rays allow astronomers to detect the presence of black
holes
• The sun will never become a Black Hole
• Stars with 10 -100 million times the mass of the sun
• Stellar- Mass Black Hole & Supermassive Black Hole
INTERPLANETARY DISTANCES
• Astronomical Unit (AU) is the average distance between the sun and
Earth (150,000,000 km)
• Light minute or light hour
• 1s = 300,000 km
• 1 min = 18,000,000 km (light minute)
• 1 AU = 8.3 light minutes
• Used to measure distances within the SOLAR SYSTEM
Example: between planets or the sun and a planet
• Light Year: used to measure outside the solar system =9.5 trillion km
Example: between galaxies and stars
Comets
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Small, loosely packed bodies of ice, rock, and cosmic dust
The core is rock, metals, and water ice
The coma surrounds the nucleus and is made of gas and dust
Comet tails—sunlight causes the comet’s ice to change to gas
thus forming the tails
• One tail is made of ionized gas (no electrons) and points away
from the sun
• The other is made of dust and gas
Comets
• Comets are found in the Kuiper belt (flat ring of objects located
beyond Neptune’s orbit)
• Oort cloud--spherical cloud of dust and ice that surrounds the
solar system far beyond Pluto’s orbit
ASTEROIDS--Asteroid Belt
pg502
• Asteroid Belt is made of asteroids between
Mars and Jupiter
• Located between the Inner Solar System and
the Outer Solar System
• Asteroids are small (1,000 km)
rocky and some metal bodies
• Revolve around the sun
Meteoroids
• Dust and debris from
asteroids and comets within
our solar system
• When enter Earth’s atmosphere
reach speeds of 35,000-250,000 km/h
• Friction heats the meteoroids to
thousands of degrees Celsius
• Glow brightly
Meteors
• The glowing trails that result when meteoroids burn up in
Earth’s atmosphere
Meteorites
• Larger bodies that pass through Earth’s atmosphere without burning
up and strike Earth
• Three types: Stony, metallic, Stony-iron meteorites
METEOR SHOWERS
• Meteors can be seen on almost
any night away from lights
• When a large number of small
• meteoroids enter Earth’s atmosphere in a short period of time
a meteor shower occurs
• Occurs when Earth intersects the orbits of comets that have
left behind a trail of dust
METEOR SHOWERS
POINTS TO REMEMBER
• The solar system formed as a result of
gravitational attraction in the solar nebula
• Gravity and pressure were major factors in the
formation of the solar system
• The sun is a star that produces energy by
nuclear fusion
• Astronomers use the astronomical unit to
measure distances in the solar system
POINTS TO REMEMBER
• The four planets of the inner solar system are small, dense, and
rocky and are close to the sun
• The inner planets, or terrestrial planets, are: Mercury, Venus, Earth,
and Mars
• The planets of the outer solar system have deep,
massive gas atmospheres
• Jupiter, Saturn, Uranus, and Neptune are the
inner planets or the gas giants
• Pluto is made of rock and ice and is a dwarf
planet
POINTS TO REMEMBER
• Moons are bodies that are smaller than planets and that orbit
planets
• Earth’s moon formed when an object collided with Earth
• The moon’s appearance changes as the moon revolves
around earth
• Moons of other planets vary greatly in size and composition
POINTS TO REMEMBER
• Comets, asteroids, and meteoroids are small bodies in our
solar system that orbit the sun
• Comets are small bodies of ice and rock that have very
elliptical orbits
• Most asteroids are located in a belt between Mars and
Jupiter
• Meteoroids are dust and debris from asteroids and comets