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70 slides:
- Solar System and Planetary Motion
- Major Planet Classifications and Orbit
- Planet Earth
- Terrestrial Planet
- Jovian Planets
- Dwarf Planets
- Origin of the Solar System
- Other Planetary Systems
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This PPT is for Grade 11 students talking about our Solar System. This was in Chapter 8 in a Filipino school curriculum.
A project assigned to the students mentioned in the PPT.
2. -Astronomy is the study of the Universe, which is
the totality of all matter, energy, space and time
In this chapter, we will explore our Solar system in a more
detailed form and more questions to be answered
4. What is the motion of the Solar System?
The planets orbit the sun, roughly in the same place. The Solar
System moves through the galaxy with about a 60° angle
between the galactic plane and the planetary orbital plane. The
Sun appears to move up-and-down with respect to rest of the
galaxy as it revolves around the Milky Way
5. Solar System
Consists of the Sun, the planets, the planetary satellites,
asteroids, comets and meteors.
The Sun has a dia (865,000 miles) of more than 700 times larger
than all the other bodies take together.
6. It is the only body of the Solar System which radiates
light. It rotates about its own axis, completing one
rotation in about 25 days.
There are 8 non-luminous planets which we only see
because they reflect light and they exhibit phases like
the moon.
7. In order of distance from the Sun, they are
Mercury, Venus, Earth, Mars, Jupiter,
Saturn, Uranus and Neptune
Between the orbits of Mars and Jupiter, there
are a large number of minor planets called
asteroids
8. PLANETARY MOTION
• States that all planets revolve around the Sun in
elliptical orbits with the Sun situated at one of foci of
the eclipse
• An ellipse is a locus of a point, such that the sum of
the distances from the point to the two foci of the
ellipse is always constant, as shown in the fig.
Kepler’s First Law
9. Kepler’s Second Law
• States that the radius vector of a planet (a line joining the centre of the
Sun to the centre of the planet) sweeps out equal areas in equal
periods
• For equal areas to be swept out in equal periods, the planets move faster in
its orbit when it is closer to the Sun and slower when it is further away
• A planet is said to be at Aphelion when in its orbit it is further away from
the Sun
• A planet is said to be at Perihelion when in its orbit it is nearest to the Sun
• Because the Sun is eccentric (not at the centre) within the Earth’s orbit, at
aphelion, the Earth is 45 million miles and at the perihelion 91.35 million
miles from the Sun. Average distance is 93 million miles. The eccentricity
(not concentric) of the Earth’s orbit is about 1/60
• In the terms aphelion and perihelion we use the suffix ‘helion’ (from the
Sun) as the distances were expressed from the Sun. If the distances are
expressed from the Earth, we use the suffix ‘gee’ (for geographic). Thus,
when the Sun is in its apparent orbit or the Moon in its orbit around the
Earth, is nearest the Earth, they are said to be at perigee, and when
farthest away from the Earth, they are said to be in apogee.
• Similarly, when distance are expressed from the Moon, we use the suffix
‘cynthion’ or ‘lune’ leading to the terms apocynthion or apolune and
pericynthion or perilune.
10. Kepler’s Third Law
Gives the relationship between the distance of a planet from the Sun and the
time it takes to complete one revolution around the Sun.
According to this law, planets which are closer to the Sun have a greater
angular velocity than planets which are further away.
Angular velocity is the angle by which an object revolves in a certain time.
Angular velocity can be expressed in degrees per unit time (second, minute,
hour, etc.), radians per unit time, or even revolutions per unit time.
11. PLANETS USED FOR CELESTIAL
NAVIGATION
Mars, Saturn, Venus and Jupiter. Apart from the Sun and Moon, Venus is the
brightest celestial body, visible in the mornings before sunrise or evenings after
sunset. Some of the planets have satellites or moons. Mercury and Venus have no
moons.
13. Galileo Galilie (1564-1642)
He is an Italian astronomer, mathematician, and
physicist. He is one of the greatest scientist of all time.
In 1609 Galileo was the first person to observe the moon
and the planets through a telescope.
14. He also discovered four of Jupiter’s moon,thus proving that the earth is not
the center of motion for all objects in the universe.
15. This observation could be explained by the heliocentric
model but ran counter to the geocentric model, which
predicted venus to only have new or crescent phases.
16. The works of Copernicus, kepler, and
Galileo were integrated by sir Isaac newton
in 1687 with the publication of the
PRINCIPIA.
17. Newton also established physical laws
determining the magnitude and direction of the
forces that cause the planets to move in elliptical
orbits in accordance with keplers laws. The
explanations of keplers laws unified the
heliocentric model of the solar system and
brought an end to the confusions.
18. The sun is the dominant mass of the solar system, possessing 99.87% of the mass of the system,
the remaining distribution of the solar system is 0.13% is shown in table 8.1, more than half of this
0.13% is the mass of Jupiter.
0.000
50.000
100.000
150.000
200.000
250.000
300.000
350.000
Mass of Solar System
Mass (Earth=1)
19. The relative distance of the planets from the sun are shown in
figure 8.6 all the orbits are all elliptical but nearly circular and
generally lie in a plane.
Note how far Jupiter is from the sun
compared with the distance of mars.
Also note that the distance from
Saturn to Neptune is greater from the
sun to Saturn (table 8.1).
20. Orbital period has the time to
take a planet to travel on one
complete orbit around the sun
It is express in terms of its
sidereal period,the time it takes
the planet to make one full orbit
around the sun relative to a fix
star. On example, the sidereal
period of the planet mercury-
that is,mercury sidereal
year(88 earth days).A sidereal
orbit period of the earth is
365.25 days.
A planet thas has smaller orbit
than the earth are classified as
inferior and those with orbits
greater than the earths as
superior. When the earth and
one of the inferior planets
(mercury or venus are lined up
on the same side of the sun, an
inferior conjunction is said to
occur).
21. A mnemonic for
remembering the order of
the planets from the sun is
the following:
My
Very
Endearing
Mother
Just
Served
Us
Nachos
Mercury
Venus
Earth
Mars
Jupiter
Saturn
Uranus
Neptune
23. The planet Earth is a solid, spherical, rocky body with oceans and an
atmosphere. Among all of the other planets in our solar system, the earth is
unique. It is the only planet with large amounts of surface water, an
atmosphere that contains oxygen, a temperature climate, and living
organisms.
24. Oxygen is a very reactive element, it mostly dominates the chemistry of the planet and it
makes up 21% of the atmosphere. Oxygen is the most abundant element in the earth’s
crust while nitrogen is the most abundant element in the atmosphere. Oxygen containing
compounds constitute 90% or more of Earth’s rocks by volume. When oxygen combines with
another substance, the process is called *oxidation.
*
25. The fraction of incident sunlight reflected by a celestial object is called its
albedo. The Earth’s albedo is 0.33, and the Moon’s is 0.07. This value
indicates that the Moon’s surface reflects 7% of the incoming sunlight
falling on its surface. The Earth reflects more light (33%) because the
clouds and water are much better reflecting surfaces then the dull, dark
surface of the moon
26. The Earth is undergoing several motions simultaneously.
Two that have major influences on our daily lives are (1) the
daily rotation of the earth on its axis and (2) the annual
revolution of Earth around the sun.
Rotation - When an object spins on an internal axis.
Revolution - Is the movement of one object around the
other.
29. What is a Terrestrial Planet?
A *terrestrial planet, telluric planet or rocky planet is a
planet that is composed primarily of silicate rocks or
metals.
*(The terms are derived from Latin words for Earth [Terra and Tellus], as these
planets are, in terms of composition, “Earth-like”)
(in order by distance from the sun, these planets are Mercury, Venus, Earth, and Mars)
Terrestrial planets have a solid
planetary surface, making them
substantially different from larger
planets, which are mostly composed
of some combinations of hydrogen,
helium, and water existing in various
physical states.
30. MERCURY
On Mercury, a day lasts almost 59 Earth days.
The daytime temperature can rise to 427 °C,
and the nighttime temperature can drop to –
184 °C.
It is the smallest planet in the solar system,
with an equal diameter of 4,879 km.
Mercury’s core makes up most of
its volume, its core is thought to be
partly molten.
31. VENUS
Venus’s diameter is 95% of Earth’s diameter, and its
mass is about 80% of Earth’s. Because they are so
similar in size, Venus is sometimes called “Earth’s
twin.” However, there are many differences between
the two planets.
Earth has prograde rotation, which means that it rotates
counterclockwise about its axis as seen from above North
Pole.
Venus has retrograde rotation, which means that is rotates
clockwise about its axis as seen also from above North Pole.
The surface of Venus is covered with thousands of volcanoes.
It also has craters.
The average surface temperature is 465 °C.
Sulfuric acid rains down unto Venus’ surface, and the
atmospheric pressure is at least 90 times that of Earth.
32. EARTH
Earth is the only planet that can support life.
It has liquid water, an energy source, an atmosphere that contains
oxygen, and a number of ecosystems for different organisms to inhabit,
Matter is continuously cycled between the environment and living things.
Organisms that produced food and oxygen by photosynthesis appeared
about 3.5 billion years ago, followed by more complex life forms.
Earth is the only terrestrial planet whose surface is divided into
tectonic plates.
The moon has a surface gravity that is only about one-sixth that if Earth.
It also has large dark areas that are plains of solidified lava and light-
colored areas that are highlands.
33. MARS
The surface of Mars is composed largely of dark, volcanic rock.
It is littered with rocks and boulders, which are covered with a powdery
dust.
The dust is the product of the chemical breakdown of rocks rich in iron
minerals. It gives the Martian soil its orange-red color.
Mars has large volcanoes and very deep valleys and canyons.
It has a very thin atmosphere, mostly composed of carbon dioxide.
Winds on Mars cause giant dust storms.
A number of features on Mars provide evidence that liquid water once
flowed on the planet’s surface and may be found beneath the surface.
35. What are the Jovian Planets?
• Mostly known as the Gas Giants- Jupiter, Saturn, Uranus and Neptune- are collectively
called the Jovian planets. This occured due to their similarity with the biggest planet in our
solar system- Jupiter*.
*In Roman mythology, Jove, was another name for the reigning god, Jupiter. (Zeus in Greek Mythology)
• Common characteristics of the Jovian Planets:
• They are larger than the Terrestrial Planets
• Posses strong magnetic fields
• Have numerous rings and moons
• Mainly composed of helium & hydrogen gases
• They have rocky cores with layers of ice above it
36. JUPITER
• Named after the chief Roman god due to its brightness and giant size
• Largest planet regarding its volume and mass
• Fastest planet, as far as rotation on a planet’s axis goes, in the solar system (Takes only about 10 hrs)
37. According to the Galileo spacecraft in 1995, the outer
atmosphere of the planet is a thin layer of clouds
composed of hydrogen, helium, methane, ammonia
& several other gases.
Cloud patterns
in Jupiter’s sky
The temperature at the top of the
clouds is about -121°C.
38. One interesting feature of the Red Giant is its
storm- the Great Red Spot. The spot exhibits an
erratic movement and changes its colors and
shape.
A little illustration to understand
just how big the Great Red Spot
is
From 1998 – 2000, 3 smaller
storms merged to make a storm
roughly the size of the Earth
As time passes by, the Great Red Spot’s size has been
decreasing.
39. Jupiter also posses rings around it
and are, maybe, composed of
collision fragments by asteroid
impacts from two small moons in
the vicinity of the ring
An illustration showing how jupiter would look like if its rings were
visible
The planet has 79 moons, 67 at the time of
the book’s writing, and its largest are
collectively called Galilean* moons.
*They are called the Galilean moons for they were
discovered by Galileo in 1610
40. SATURN
• Named after the Roman god of agriculture
• Famous for its stunning array of rings
• Has the lowest density (0.70 g/cm³) in the solar system
• Takes about 10.2 hrs to rotate but 30 yrs to orbit the Sun
41. Real colors of Saturn’s rings
The ring system shows structures on many scales,
ranging from the divisions of major rings (labeled C, B & A
rings.)
Cassini Division
A distinct gap between B & A rings
that is named after the Italian-
French astronomer Giovanni
Cassini who discovered it in 1675
The rings are mainly made out
of reflective water ice particles
and of rocks ranging in size
from dust grains to huge
boulders. These rocks are
believe to be pieces of
shattered moons,asteroids or
comets. They are so wide that
they extend until to its very last
moon
Closest picture
taken of the
planet
The temperature at the top
of the clouds is about -
180°C.
42. Saturn has 82 moons (62 at the time the book was written) and 29 more,
unnamed.
Saturn’s core is a small, solid core surrounded by a layer
of ice, a layer of metallic hydrogen and an outer layer of
liquid hydrogen and helium.
The most amusing moon Saturn has is
Titan. It has a nitrogen-rich Earth-like
atmosphere and a landscape featuring
dry river networks and hydrocarbon
lakes (liquid bodies that contain
liquid ethane and methane)
43. URANUS
• Discovered on 1781 by an English
astronomer, William Herschel
• Named after a Roman mythology
character, Uranus who was the father of
the Titans and the grandfather of
Jupiter
44. The planet’s color is due to the methane that is co-existing with
the hydrogen and helium in the atmosphere. This specific gas
absorbs the red end of the sunlight spectrum.
Uranus also have a ring system.
It is mainly made out of dark
material, from small grains to
particles up to 1 m in diameter.
Due the lack of ice, the rings do
not reflect light as well as the
rings of Saturn. In total it has 13
rings
The planet has 27 moons that
are all named after characters
that show up in Shakespear’s
works
45. The planet’s rotation is a complete mystery. It rotates,
practically, on its side having a 98° inclination
The temperature at the top of the clouds is about
-224°C
Uranus has a solid core covered
with mantle and its atmosphere
contains ammonia and methane
46. NEPTUNE
• First discovered in 1846 by, Johann G.
Galle, a German astronomer. He shared
the credits for its discovery with John
Couch Adams and Urbain Le Verrier
(English and French mathematicians).
• Named after the Roman God of the sea,
Neptune, the son of Saturn and the
brother of Jupiter and Pluto.
47. Adams and Le Verrier used Newton’s law of
gravitation. They made calculations to predict where
to look for a suspected planet that was disturbing the
orbital motion of Uranus.
Neptune has 13 moons
and its largest moon is
Triton
The temperature at the top of the
clouds is about -218°C.
48. It also has it’s own ringsystem that
consists of 11 rings
It has a its own storm
that has the most
strong winds among
the storms of any
planet in our solar
system (2,100 km/h)
Cloud patterns in Neptune
This planet’s core is simillar to
Uranus and is usually mistaken for it.
50. How can a solar system body
be categorized as a planet?
• It must orbit the sun
• It must have sufficient mass for self-gravity
to form a nearly round shape
• It must be the dominant body within its orbit;
that is, it must have cleared the
neighborhood around its orbit
An image of Earth and Pluto side by side
51. PLUTO
According to the 3rd criteria of a
solar system body being a planet,
Pluto couldn’t make the cut. As it
enters Neptune’s orbital plane,
it is no more the dominant body
at its orbit.
This small, distant and cold
dwarf planet was named
after the Roman God of the
Underworld
52. Percival Lowell ( 1855 – 1916 ) was one of the
astronomers who attempted to calculate a far
away planet that disturbing the orbital motion
of Neptune. Unfortunately he didn’t manage
doing it before he dies.
14 years after the astronomer’s
death, Clyde Tombaugh worked at
Lowell’s observatory and discovered
the planet only 6° away from Lowell’s
prediction.
53. CERES
Ceres is a dwarf planet that
resides between Mars &
Jupiter. It was discovered
by Giuseppe Piazzi on
1801 and was named after
the Roman Goddess of
agriculture and fertility.
It’s role in our solar system
ranged from being a planet at
first, re-categorized as an
asteroid for a long time and is
now a dwarf planet.
The smallest dwarf planet in our
solar system is said to have
textured surface and pristine
water from when the solar
system was formed
55. Nebular Hypothesis
Proposed by Emmanuel Swedenborg,
Immanuel Kant, and Pierre-Simon Laplace
in1700s :
“A rotating cloud of gas and dust that cools and
contracts in the middle to form the sun and the
rest into a disc that becomes the planets”
A solar nebula positioned in space among the
stars of the Milky Way.
56. Evidence to support the nebular hypothesis:
1. Planets and moons revolve in a counterclockwise direction.
2. Almost all planets and moons rotate on their axis in a
counterclockwise direction.
3. Planetary orbits are aligned along the sun’s equatorial
plane.
57. Protoplanets Hypothesis
Developed by Carl von Weizsacker and Gerard Kuiper
“The Solar System begins to form, as a rotating cloud,
or nebula collapses. But instabilities develop in the
nebula causing dust particles to pull together. Then the
dust particles merge into billions of planetesimals then
collide and form protoplanets. At the center of the
nebular disk the protosun increases in mass and
becomes a star by the process of hydrogen fusion.”
“protosun” - “earliest form of”
Over a vast expanse of time, the protosun evolved into
the current Sun, and the protoplanets evolved into the
planets of our present solar system.
59. EXTRASOLAR PLANETS
Known also as EXOPLANETS, these are the planets,
outside our solar system, that orbit stars other than our
own Sun.
There is an estimated 100 billion galaxies, that contain
billions of stars, where it would seem that other planetary
systems than our own would had formed
Now the question is, why can’t we see or find them?
60. IT IS ALL ABOUT THE DISTANCE
Planets are relatively small compared to
their parent star and lie close to them.
Scientists uses to their advantage the gravitational pull
planets have on their parent star to detect a slight
“wobble” it causes to identify their existence.
61. ASTROMETRY
One of the methods used to find exoplanets is called
Astrometry. This branch of astronomy deals with
the measurement of positions and motions of
celestial objects.
As the star moves through space, the gravitational
tugging shows a tiny deviation from the straight-line
path that a star without a planet(s) would follow, and
the star is observed to “wobble” slightly.
The downside of this method is that it is very time
consuming as planets take months or years to orbit
their parent star.
63. DOPPLER EFFECT
With this method, the star alternately
moves towards and away from us. This
happens because of the effect of the
planet’s and parent star’s gravitational
balance (when a massive planet and a
parent star both revolve about their center
of masses).
In this method, scientists can detect a
slight change within the color spectrum of
the parent star as it slightly goes to the
from the blue to the red end of it due to
the wobble.
It is, however, limited to massive planets
as their gravitational pull is greater than
that of smaller planets.
65. PULSARS
This method relies on radio waves of
rapidly spinning stars called Pulsars. By
accurately measuring the time of arrival of
these pulses, planets can be discovered
from variations in these radio signals. The
very first exoplanet was discovered using
this method in 1992
67. TRANSIT METHOD
This method relies on the dimming of a star.
Light from a star is dimmed if a planet passes
in front of it.
The amount of the light dimmed and the length
of time of the eclipse can give clues about the
size, mass and atmosphere of the orbiting
planet.
69. Gleis 581g
This exoplanet named Gleis 581g is the
very first exoplanet discovered that resides
within the “life-zone” of its own solar
system. It is a mega planet that is very
much earth-like. It was discovered on 2010
https://www.youtube.com/watch?v=wJXSSYyIVqw
