1. ASTRONOMY
SOLAR SYSTEM
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
There are 8 planets and a dwarf planet. The Sun is the center of our solar system

2. MERCURY Smallest and fastest planet Orbit is 88 days
Surface is rocky and covered
with craters
Has no moon

3. VENUS *Smaller than the Earth
*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)

4. EARTH The Earth is 93 million miles
(150 million km)
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

5. 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

6. 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

7. 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

8. 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

9. 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

10. 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/ Carpo 16. S/ Euporie 18. S/ S/2003
20. Thelxinoe 21. Euanthe 22. Helike 23. Orthosie S/2003
26. Ananke 27. Praxidike 28. Harpalyke 29. Hermippe 30. Thyone
31. Mneme 32. S/ Aitne 34. Kale 35. Taygete 36. S/2003
37. Chaldene 38. S/ S/ S/ Erinome 42. Aoede 43. Kallichore 44. Kalyke 45. Eurydome 46. S/ Pasithee
48. Cyllene 49. Eukelade 50. S/ Hegemone 52. Arche
53. Carme 54. Isonoe 55. S/ S/ Pasiphae 58. Callirrhoe 59. Sinope 60. Sponde 61. Autonoe 62. Megaclite 63. S/2003

11. SATURN 800 times bigger than the Earth Many moons (more than 53)
Major moons: Distance Radius Mass Satellite (000 km) (km) (kg) Discoverer Date Pan ? Showalter 1990 Atlas ? Terrile 1980 Prometheus e17 Collins 1980 Pandora e17 Collins 1980 Epimetheus e17 Walker 1980 Janus e18 Dollfus 1966 Mimas e19 Herschel 1789 Enceladus e19 Herschel 1789 Tethys e20 Cassini 1684 Telesto ? Reitsema 1980 Calypso ? Pascu 1980 Dione e21 Cassini 1684 Helene ? Laques 1980 Rhea e21 Cassini 1672 Titan e23 Huygens 1655 Hyperion e19 Bond 1848 Iapetus e21 Cassini 1671 Phoebe e18 Pickering 1898
SATURN
800 times bigger than the Earth
Many moons (more than 53)
Titan is the largest moon of Saturn
Has rings

12. 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.

13. URANUS 300 times bigger than the Earth 84 Earth years to orbit the sun
Strange thing: Orbits the sun on its side
Has rings

14. NEPTUNE 300 times larger than the Earth Two moons
Jupiter, Saturn, Uranus, Neptune are called
OUTER PLANETS and GAS GIANTS

15. PLUTO Dwarf planet in Kueper Zone Rock and ice Charon is Pluto’s moon
Charon is the COLDEST place on the entire solar system

16. 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

17. GALAXIES Spiral galaxies have a bulge at the center and spiral arms.
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.

18. 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

19. 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

20. 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

21. 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

22. 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

23. 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 radiates with the power of 10 trillion suns

24. 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

25. 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

26. 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

27. FORMATION OF THE SOLAR SYSTEM
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

28. GRAVITY AND THE UNIVERSE
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

29. 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.

30. 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

31. 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

32. 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 10,000,0000 C in its center
Hydrogen nuclei combine to become helium
This is called nuclear fusion
Causes energy to be released

33. 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

34. 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

35. 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

36. H-R DIAGRAM
The Sun *Middle age *5 billion years old Blue = Hot Yellow = Medium Red = Cool

37. 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

38. THE AGING OF MASSIVE STARS
PULSARS If a neutron star is spinning, it is called a pulsar
Pulsars send out beams of
radiation that sweep across
space like a lighthouse over
the ocean
Detected by radio telescopes
as pulses

39. 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)

40. 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

41. BLACK HOLES

42. BLACK HOLES

43. 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 million times the mass of the sun
Stellar- Mass Black Hole & Supermassive Black Hole

44. 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

45. Comets 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

46. 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

47. 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

48. Meteoroids Dust and debris from asteroids and comets within
our solar system
When enter Earth’s atmosphere
reach speeds of 35, ,000 km/h
Friction heats the meteoroids to
thousands of degrees Celsius
Glow brightly

49. Meteors
The glowing trails that result when meteoroids burn up in Earth’s atmosphere

50. Meteorites
Larger bodies that pass through Earth’s atmosphere without burning up and strike Earth
Three types: Stony, metallic, Stony-iron meteorites

51. 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

52. METEOR SHOWERS

53. 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

54. 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

55. 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

56. 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