Here are the key differences between asteroids, comets, and meteoroids: - Asteroids: Asteroids orbit the Sun and are made of rock and metals. They are usually found in the asteroid belt between Mars and Jupiter. - Comets: Comets are small icy bodies that orbit the Sun and have long tails made of dust and gas that form when they are heated by the Sun as they orbit. They come from farther out in the Solar System. - Meteoroids: Meteoroids are much smaller than asteroids and comets, ranging from small grains to large boulders. They orbit the Sun like asteroids. When meteoroids enter Earth's atmosphere, they glow from friction and are called

1. Our Solar System

2. Brief History
 The Earth is the
center of the
universe and the
sun and moon
moved in perfect
circles around the
earth

3. Ptolemy
 An astronomer living
in Egypt who
supported Aristotle’s
Theory

4. Nicolaus Copernicus
 A Polish
astronomer, propose
d that the sun was
the center of the
universe and that all
other objects
revolved around the
sun

5. Johannes Kepler
 Discovered that the
planets move in
ellipses around the
sun. His discoveries
supported the ideas
of Copernicus

6. Galileo Galilei
 With the aid of a
telescope to back up
the beliefs of these
scientists, Galileo
supported
Copernicus claims.

7. Isaac Newton
 Formulated the first
basic theories of
gravitation and all
objects in the
universe attracted
each other.

8. SUN

9. The Sun
It is the star at the center of the Solar
System.
About three quarters of its mass consists of
hydrogen, while the rest is mostly helium.
The energy of this sunlight supports almost
all life on Earth by photosynthesis, and drives
Earth's climate and weather

10. Parts of the Sun
1. Core – sun’s center
2. Photosphere – the first layer of the sun
3. Chromosphere – innermost layer of the sun’s
atmosphere
4. Corona – extensive outer layer of the sun’s
atmosphere
5. Sunspots – dark areas on the surface of the sun
6. Solar flares – flashes of bright light are visible on
earth
7. Prominence – a giant column of hot gases formed
in the chromosphere that extends to the corona

13. Stars
 A star is a massive, luminous ball of
plasma held together by gravity.

14. Constellations
 collection of stars linked together to represent a
person, animal or object.
 is an internationally defined area of the celestial
sphere.

15. Zodiacal Family
 Aquarius, the water
bearer
 Aries, the ram
 Cancer, the crab
 Capricorn, the goat
 Gemini, the twins
 Leo, the lion
 Libra, the scales
 Pisces, the fish
 Sagittarius, the archer
 Scorpius, the scorpion
 Taurus, the bull

16. Supergiants
 Have diameters up
to 1000 times the
diameter of the sun
 Examples:
Rigel, Betelgeuse, a
nd Antares

17. Stars
 By using a
spectroscope,
astronomers have
found out that stars
have similar
composition, the
most common is
hydrogen. He, O,
Ne, C are other
elements

18. Stars
 Blue stars are the hottest and youngest
stars followed by white, yellow, red-
orange, and red as the oldest stars.

19. Stars
 New stars are born from the gases in
the nebulae that clump together
because of gravity

20. Life Cycle of a Star

21.  Protostar -

22. NEBULA
 a region or cloud of interstellar dust and
gas

23.  Stars are born in nebulae. Huge clouds of dust and
gas collapse under gravitational forces, forming
protostars. These young stars undergo further
collapse, forming main sequence stars.
Stars expand as they grow old. As the core runs out
of hydrogen and then helium, the core contracts and
the outer layers expand, cool, and become less
bright. This is a red giant or a red super giant
(depending on the initial mass of the star). It will
eventually collapse and explode. Its fate is
determined by the original mass of the star; it will
become either a black dwarf, neutron star, or black
hole.

24. Our Solar System
Our solar system is made
up of:
 Sun
 Planets
 Their moons
 Asteroids
 Comets

25. Inner Planets
The inner four rocky
planets at the center
of the solar system
are:
 Mercury
 Venus
 Earth
 Mars

26. What is a planet?
The definition of planet set in 2006 by
the International Astronomical Union (IAU)
states that in the Solar System a planet is
a celestial body that:
 is in orbit around the Sun,
 has sufficient mass to assume hydrostatic
equilibrium (a nearly round shape), and
 has "cleared the neighbourhood" around its
orbit.

27. The Planets
Mercury is the planet that is closest to our
Sun. Neptune is the farthest.
Remember the order of the planets like
this:
My Very Educated Mother Just Showed
Us Nothing
which means
Mercury Venus Earth Mars Jupiter Saturn
Uranus Neptune

28. Mercury
What are Mercury‘s features?
 smallest planet
 nearest to the sun
 one Mercury-year is a quarter Earth-year
 Mercury is very difficult to be spotted with the
naked eye
 Mercury has no moons

29. Venus
What are Venus‘ features?
 it is a medium sized planet, 2.5 times as large as
Mercury
 second nearest to the sun
 Venus is very well visible to the naked
eye, always close to the sun before sunrise or
after sunset
 Venus has no moons

30. Earth
What are Earth‘s features?
 it is a medium sized planet, a bit larger than
Venus
 (probably) the only planet with liquid water in
our Solar System
 the Earth has one moon
 (probably) the only planet with intelligent life in
our Solar System

31. Mars
What are Mars‘ features?
 it is a small sized planet, half as large as Earth
 Mars is well visible to the naked eye
 Mars has two moons: Phobos and Deimos
 Mars has been visited by robotic vehicles:
Pathfinder, Spirit and Opportunity
 the question for (former) life on Mars is still
unsolved

32. Jupiter
What are Jupiter‘s features?
 it is the largest planet of the Solar System,
more than 1.300 Earths could fit inside
 Jupiter is well visible to the naked eye
 The Great Red Spot on its surface is a giant
storm as wide as three Earths
 Jupiter has 63 moons! (the largest are
Io, Callisto, Ganymede and Europa)

33. Saturn
What are Saturn‘s features?
 it is the second-largest planet of the Solar
System, only a bit smaller than Jupiter
 Saturn is well visible to the naked eye
 the famous rings can be seen with small
telescopes
 Saturn has at least 34 moons! (recently a probe
landed on Jupiter‘s moon Titan)

34. Uranus
What are Uranus‘ features?
 it is medium sized planet of the Solar System
 it is quite far away but still can be spotted with
small telescopes
 like Saturn, Uranus has a system of rings

35. Neptune
What are Neptune‘s features?
 it is medium sized planet of the Solar
System, only a little bit smaller than Uranus
 it is quite far away but still can be spotted with
small telescopes
 Neptune has four rings and at least 13 moons

36. Pluto
What are Pluto‘s features?
 it is already a dwarf planet
 Since Pluto is far away and so small, you need a
medium-sized professional telescope or a good
amateur telescope to spot it.
 No one knows what Pluto looks like – it‘s too far
away and too small. The picture in the
background is an artist‘s rendition.

37. Pluto
Pluto is now classified as a
dwarf planet. It is unusual
because it is not a gas
giant and it does not seem
to be terrestrial.
The motion of Pluto’s orbit
suggests that Pluto may
have been one of
Neptune’s moons at one
time.
Pluto also has a moon called
Charon which is about the
same size as Pluto.

38. Planetary Summary
Closest to Brown crater 59 days
the Sun 0.386 0 Chunks of rock
none
To orbit Sun
2nd from Hot enough to A 1.7 KM high
0.72 0 CO2, N2
the Sun melt lead Volcano
Volcanoes,
3rd from
1 1 Soil and Water N 2, O 2 hurricanes
the Sun
Reddish Volcanoes,
4th from 0.5326 2 CO2, N2
the Sun coloured soil glaciers
5th from Coloured Bands, Winds,
the Sun
11 63 Great Red Spot H2, He, CH4 hurricanes
6th from Surface temp. is H2, He, CH4 Windy, clo
the Sun
10 33 About -180o udy
7th from Polar hood over 500 km/h
the Sun
4 29 South pole H2, He, CH4 winds
8th from 3.8 13 It’s blue. H2, He, CH4 Dark spot
the Sun
9th from 0.186 3 Cold and rocky none Rotates on
the Sun side

39. Earth’s Moon
 Dry, airless, and barren world with extreme
temperature
 The moon is actually moving away from earth
at a rate of 1.5 inches per year.
 The moon is not round, but egg shaped with
the large end pointed towards earth.
 The earth rotates about 1000 mph. By
comparison, the moon rotates about 10 mph

42. Asteroids
 Small bodies
 Believed to be left
over from the
beginning of the solar
system billions of
years ago
 100,000 asteroids lie
in belt between Mars
and Jupiter
 Largest asteroids
have been given
names

43. Meteoroids
 Small pieces of matter (some as grains
of sand) that also orbit the sun
 When a meteoroid enters the earth’s
atmosphere, friction causes it to heat
up and glow (meteors)
 Some meteors that enter the earth’s
atmosphere do not burn up and they
land on earth (meteorites)

44. Comets
 Small icy bodies
 Travel past the Sun
 Give off gas and dust
as they pass by

45. Halley’s Comet
 It passes the Earth
every 76 years. Its
last pass was in
1986

46. What is the difference between an
asteroid, comet, and meteoroid?
 Asteroid:A relatively small, inactive
body, composed of rock, carbon or
metal, which is orbiting the Sun.
 Comet:A relatively small, sometimes active
object, which is composed of dirt and ices.
Comets are characterised by dust and gas
tails when in proximity to the Sun. Far from
the Sun it is difficult to distinguish an
asteroid from a comet.
 Meteoroid:A small particle from an
asteroid or comet orbiting the Sun.

47. Movements of the Earth
 Rotation – earth rotates on its axis
which is tilted at an angle of 23.5O
earth rotates towards the East
 Revolution – the entire trip around the
sun; 365 days, 5 hours, 48 minutes,
and 46 seconds

48. Terms to be remembered:
 Eclipse - an astronomical event that
occurs when an object is temporarily
obscured, either by passing into the
shadow of another body or by having
another body pass between it and the
viewer.

53. Terms to be remembered:
 Perigee – moon’s orbit is closest to
Earth
 Apogee – moon’s orbit is farthest to the
Earth
 Umbra – small inner shadow
 Penumbra – large outer shadow

54. Space News
 Space exploration is one of the most
fascinating features of modern times.
Why do you think it is important to
explore the space?

55. arE You Ready For your
PT???