An introduction to astronomy and the scientists that have made great contributions to the science.

1. OUR SOLAR SYSTEM

2. SOLAR SYSTEM OVERVIEW
OUR SOLAR SYSTEM INCLUD
●SUN
●EIGHT PLANETS & THEIR SATELL
●THREE DWARF PLANETS
●ASTEROIDS
●COMETS
●METEOROIDS

3. THE PLANETS
JUPITE
R SATU
RN
URAN
US
NEPTU
NE
EART
H
PLUT
O

5. ADD THE SUN

6. HOW SMALL ARE WE?

7. ASTEROIDS
Most lie between Mars and Jupiter
●Microplanets: small, rocky bodies
●Irregular shapes

8. ●Large, "dirty snowballs"
●Composition:
●Frozen gases
●Rocky and metallic materials
●Produces a glowing head called
the coma and a tail that points
away from the sun
COMETS

9. COMET HALE-BOPP

10. METEOROIDS
METEOROID –
small solid particle
that travels through
space
METEOR – when a
meteoroid enters
Earth’s atmosphere,
“shooting star”
METEORITE –
when a meteoroid
reaches the Earth’s
surface

11. WHICH ONE OF THESE IS
NOT LIKE THE OTHERS?

12. RIGHT!
PLUTO
DOES NOT
BELONG…

13. THREE MAIN CATEGORIES
OF OBJECTS IN OUR SOLAR
SYSTEM:
1. PLANETS: The eight worlds starting with Mercury and
moving out to Venus, Earth, Mars, Jupiter, Saturn,
Uranus and Neptune.
2.SMALL SOLAR SYSTEM BODIES: All other objects orbiting
the sun.
3.DWARF PLANETS: Pluto and
any other round object that
"has not cleared the
neighborhood around its orbit,
and is not a satellite."

14. EARLY HISTORY OF
ASTRONOMY
ASTRONOMY: the study of the
UNIVERSE
ANCIENT GREEKS – Golden age of early
astronomy
• Used geometry and trigonometry to measure
sizes and distances of the sun and moon
• ARISTOTLE – the Earth is round
• GEOCENTRIC MODEL –Earth is the center

15. EARLY HISTORY OF
ASTRONOMY
Birth of modern astronomy 1500s and 1600s
Five noted scientists
1. NICOLAUS COPERNICUS (1473-1543)
⚫Concluded Earth was a planet
⚫HELIOCENTRIC MODEL – Sun is the center

16. EARLY HISTORY OF
ASTRONOMY
2. TYCHO BRAHE (1546-
1601)
●Made most precise
observations

17. Early History of Astronomy
3. JOHANNES KEPLER (1571-1630)
●Planets revolve around the Sun
●Three laws of planetary motion

18. EARLY HISTORY OF
ASTRONOMY
4. GALILEO GALILEI (1564-1642)
●Constructed a telescope and saw the
universe in a new way
●Discovered:
●Four moons of Jupiter
●Planets appeared as disks
●Phases of Venus
●Features on the Moon
●Sunspots

19. EARLY HISTORY OF
ASTRONOMY
5. SIR ISAAC NEWTON (1643-1727)
●Law of universal gravitation
●Explained planetary motion

20. TELESCOPES
Tools used to help astronomers see CELESTIAL (space)
objects with greater detail by:
1. GATHERING MORE LIGHT
than your eye can (dim objects are
easily seen)
2. MAGNIFYING IMAGES to
separate distant objects from one
another

21. HUBBLE SPACE
TELESCOPE
OVER 350 MILES FROM
EARTH
Hubble Space Telescope Size:
Length: 43.5 ft (13.2 m)
Weight: 24,500 lb (11,110 kg)
Maximum Diameter: 14 ft (4.2 m)
Hubble is nearly the size of a large
school bus—but it can fit inside a
space shuttle cargo bay.

22. HUBBLE FOUND THAT GALAXIES ARE
SPEEDING AWAY FROM EACH OTHER,
CONSISTENT WITH A GENERAL
EXPANSION OF THE UNIVERSE.
THIS IS CALLED THE BIG BANG.

23. DEEP SPACE IMAGE

24. OPTICAL TELESCOPES
Use lenses and mirrors to collect starlight and
light reflected off of planets
Two main types:
⚫REFRACTING – simple refractors uses two lenses.
One lens collects the light, and the other magnifies the
image.
⚫REFLECTING – uses a large curved mirror to
gather and focus the light. Another lens magnifies the
image.

25. REFRACTING – SIMPLE OPTICAL
TELESCOPE

26. REFLECTING– ADVANCED OPTICAL
TELESCOPE

27. OPTICAL
TELESCOPES
Keck Telescopes
Summit view of the twin Keck telescopes, located at 13,600 atop a
dormant volcano in Hawaii.

28. KEPLER’S LAWS
1. THE LAW OF
ELLIPSES
The Path of the planets about
the sun is elliptical in shape,
with the center of the sun
being located at one focus.

29. 2. THE LAW OF EQUAL AREAS
An imaginary line drawn from the center of the sun to the
center of each planet will sweep out equal areas in equal
intervals of time.
KEPLER’S LAWS

30. 3. THE LAW OF HARMONIES
Compares the orbital period and radius of orbit
of a planet to those of other planets.
KEPLER’S LAWS

31. Astrophotography

32. Classification of Galaxies
based on shape!
Spiral-
Irregular-
Elliptical-
Galaxies are a system of stars, gases, dust and other
matter that orbits a common center of gravity.
Scientists that are searching for new solar systems
look for clouds of gas and dust.
All galaxies are made of the same materials.

33. How do we know other
stars have planets?
Periodic dimming of stars
Milky Way Galaxy
• Our solar system is surrounded by newly formed
stars.

35. THE WAY WE MOVE
ROTATION
REVOLUTION
PROCESSION
TILT
NUTATION
BARYCENTER

36. WHAT IS
ROTATION?
The turning or spinning of a body on its
axis.

37. EARTH’S ROTATION
The average
ROTATION PERIOD of
the Earth with
respect to the SUN is
24 hours (the mean
solar day).

38. Rotation effects the core.
• Earth’s liquid metal outer core spins because of
rotation.
• The solid metal inner core does not spin.
• This phenomenon creates the magnetosphere
• The magnetosphere diverts harmful solar
radiation from space away from Earth’s surface.
• The interaction of the charged particles with
Earth’s magnetosphere creates something
amazing.
• Auroras boreales

39. WHAT IS
REVOLUTION?
The motion of a body along a path around some point
in space.
This is also called ORBITAL MOTION

40. EARTH’S
REVOLUTION
It is the orbital period of EarthIt is the orbital period of Earth, equal to
365.25636042 mean solar days.

41. What is Precession?
The slight movement of Earth’s axis over 26,000
years.

42. DIURNAL MOTION OF
STARS
We cannot detect earth’s rotation,
so it appears to us as if the stars
(and Sun and Moon and planets)
are rotating around us: they rise in
the east and set in the west, once a
day.
This is called DIURNAL MOTION.

43. TILT OF EARTH ON
AXIS

44. A FEW MORE WAYS TO
MOVE
NUTATION
–the wobble
Change in the angle of the axis (1/2 degree)
BARYCENTER
The point between two objects where they balance each
other.
Example: The moon always faces the
Earth, due to the force of gravity from
both objects. “Dark Side of the Moon”

45. STARS
The lifespan of stars varies from thousands of years for massive stars
to billions for smaller stars. Our Sun, which is of average mass, is
predicted to live for about 10 billion years (it is about halfway
through).

46. HERTZSPRUNG - RUSSELL
DIAGRAM

47. TILT OF EARTH ON
AXIS

48. SPECIAL DAYS OF
THE YEAR
• WINTER SOLSTICE first day of winter,
shortest day of the year
• VERNAL EQUINOX first day of spring,
equal day and night
• SUMMER SOLSTICE first day of
summer, longest day of the year
• AUTUMNAL EQUINOX first day of
autumn (fall), equal day and night

49. Seasons

50. DEFINITION
One of the four periods of the year
(spring, summer, autumn, and winter),
beginning astronomically at an
equinox or solstice, but geographically
at different dates in different climates.

51. SPRING
• Begins on the vernal equinox
• Usually occurs on March 21 or 22 in the
northern hemisphere
• Tilt neither toward or away from sun
• Equal day and Night

52. SUMMER
• Begins on the summer solstice
• Usually occurs on June 21 or 22
in the northern hemisphere
• Tilt toward the sun
• Longest day of the year

53. FALL
• Begins on the autumnal equinox
• Usually occurs on September 22 or 23 in
the northern hemisphere
• Tilt neither toward or away from sun
• Equal day and night

54. WINTER
• Begins on the winter solstice
• Usually occurs on December 21
or 22 in the northern
hemisphere
• Tilt away from sun
• Shortest day of the year

55. Land masses predict temperature
• Land heats up and cools fast
• Water heats up and cools slowly
• Water also stores solar energy
• The more land in the temperate zone, the
warmer the Earth will be.
• What was the weather like during this
time?

56. WHAT CAUSES
SEASONS
TILT! Either toward or away from the sun.
•Tilt TOWARD the sun is maximized during Northern
Hemisphere summer in late June (the "summer
solstice").
⚫The amount of sunlight reaching the Northern Hemisphere is at a
maximum.
•Tilt AWAY from the sun is maximized during
Northern Hemisphere winter in December (the “winter
solstice").
⚫a minimum of sunlight reaches the Northern Hemisphere.
**The seasons are reversed in the Southern Hemisphere

57. INTERESTING FACTS
• The sun is actually closest to the Earth during
Northern Hemisphere winter (not summer).
• Because of this, the amount of sunlight
averaged over the whole Earth, is as much as
7% more intense in the winter than the
summer.
• Despite this fact, the global-average surface
temperature is warmer in Northern
Hemisphere summer, due to the much
greater expanse of land there, and since land
heats to a higher temperature than the ocean

58. LIFE CYCLE OF STARS
The lifespan of stars varies from thousands of years for massive stars
to billions for smaller stars. Our Sun, which is of average mass, is
predicted to live for about 10 billion years (it is about halfway
through).

59. HERTZSPRUNG - RUSSELL
DIAGRAM

60. Energy from
the Sun
Essential Question:
Describe the energy required for the
sun to transmit electromagnetic
radiation across the solar system?

61. LAYERS OF THE SUN
• Interior: core
⚫cannot be seen
⚫where nuclear fusion occurs
• PHOTOSPHERE
⚫Photo =“light” Sphere = “ball”
⚫visible “surface” of the sun
• Sol has consumed about half its energy!
• Atmospheric layers
• CHROMOSPHERE – thin layer of hot gases
⚫CORONA – “crown” outermost portion, produces the
solar wind
⚫Earth’s magnetic field blocks the winds from reaching our surface

62. PRODUCTION OF
ENERGY
• COMBUSTION – burning fossil fuels
• RENEWABLE SOURCES – capture energy from the
sun, wind, water to produce electricity
• NUCLEAR REACTIONS – when atomic particles
interact to form different particles
⚫FUSION
⚫FISSION

63. FUSION
• Done in the interior of the sun
• Less massive nuclei combine to form more massive
nuclei
• 4 hydrogen atoms fuse into 1 helium atom.
• This requires a high temp
to fuse. 15,000,000℃
• Outward pressure keeps
stars from collapsing

64. FISSION
• Able to do on earth (Nuclear Energy)
• More massive nuclei are bombarded by neutrons
and split to less massive nuclei
• Emits heat energy

65. Stars
• Large stars burn through fuel quickly and die fast
• Small stars burn slowly, but have less radiant
energy.
• H-Hydrogen and He-Helium are the major
elements found in stars.

66. ENERGY FLOW
Energy is transferred by ELECTROMAGNETIC
RADIATION
This includes all energy types that travel as waves from
X-rays to visible light to microwaves and radio waves
Solar energy (0.023%) is used by plants through
photosynthesis to make chemical
energy (sugar).
Light is required for life.

67. FORMS OF ENERGY
PRODUCED
LIGHT
⚫Acts like a wave and particle
⚫Photons are a stream of particles that push on
matter
⚫This push is what causes a comet’s tail
HEAT
⚫The sun is extremely hot (15 million K at core)
⚫Waves of heat are ejected into space at all angles

68. LIFE CYCLE OF STARS
The lifespan of stars varies from thousands of years for massive stars
to billions for smaller stars. Our Sun, which is of average mass, is
predicted to live for about 10 billion years (it is about halfway
through).

69. HERTZSPRUNG - RUSSELL
DIAGRAM