1. By Composition
•
Terrestrial or Rocky planets
–
–
–
–
–
–
•
Solid surfaces
Composed primarily of rock
Have relatively high densities
Slow rotation
No rings
Few satellites
Examples:
– Mercury, Venus, Earth, and Mars
2. • Jovian or Gas planets
– Composed primarily of hydrogen and
helium
– Generally have low densities
– Rapid rotation
– Rings
– Lots of satellites
• Examples:
– Jupiter, Saturn, Uranus, and Neptune
3. •
Small planets
By Size
–
•
•
Example:
– Mercury, Venus, Earth, Mars
Big planets
–
•
Have diameters less than 13000 km
Have diameters greater than 48000 km
Example:
– Jupiter, Saturn, Uranus and Neptune
4. By Relative Position
from Sun
•
The asteroid belt between Mars
and Jupiter forms the boundary
between the inner solar system
and the outer solar system
•
Inner Planets:
– Mercury, Venus, Earth, Mars
•
Outer planets:
– Jupiter, Saturn, Uranus, Neptune
8. Properties of Dwarf Planet
• Must orbit the Sun
• Does not emit light
• Must be smaller than 3031 miles in diameter
• Large enough so that its own gravity pulls it
into the shape of sphere
• Due to weaker gravity, it is unable to clear out
its orbit
9. List of Dwarf Planets
Following is the list of dwarf planets:
1.
2.
3.
4.
5.
Eris
Pluto
Makemake
Haumea
Ceres
15. • The god of the dead and
underworld
Pluto
– Because it is dark and desolate
• Formerly the smallest of the nine
"traditional" planets
• But in 2006, it was demoted to
dwarf planet status
• Second largest dwarf planet
16. • Moon 3
– Largest moon is called Charon, which
is half the size of Pluto
• Unusual orbit
– Once every 248 Earth years, Pluto
swings inside the orbit of Neptune
– It stays there for twenty years
– During those twenty years, Pluto is
closer to the Sun than Neptune
23. Haumea
• Found in the Kuiper Belt
• Has an ellipsoidal; not a sphere
– Its ellipsoidal shape is thought to
result from its rapid rotation
• In much the same way that a water
balloon stretches out when tossed with
a spin, and not from a lack of sufficient
gravity to overcome the compressive
strength of its material
25. Ceres
•
Located in the asteroid belt
between Mars and Jupiter
•
When Ceres was first discovered
–
–
–
–
It was called a comet
Then called a planet
Then called an asteroid
Since 2006, it has been called a
dwarf planet
27. Moon
Definition:
– A celestial body that makes an orbit around a planet,
including the eight major planets, dwarf planets,
and minor planets
• Also referred as planet’s natural satellite
• More than 170 known natural satellites
• Moon is much smaller than its planet
31. Comet
Definition
– A celestial object consisting of a
nucleus of ice and dust and, when
near the sun, a “tail” of gas and
dust particles pointing away from
the sun
• Orbits around the sun
• Comets have a coma or a tail
• They are composed of dirt and
ices
32. • A small, active celestial body
• Comets are characterized by dust
and gas tails when in proximity to
the Sun
• However, far from the Sun it is
difficult to distinguish an asteroid
from a comet
35. Asteroid
Definition
– A relatively small, inactive body,
composed of rock, carbon or
metal, which is orbiting the Sun.
• Asteroids are rocky
• Most of them exist in the
asteroid belt located between
Jupiter and Mars
39. Meteor
Definition
– Literal meaning The flash of light
you see
– A meteoroid that is observed as it
burns up in the Earth's atmosphere a shooting star
• They are asteroids that have
succumbed to earths gravity
41. Meteorite
Definition:
– A meteoroid that survives its
passage through the Earth's
atmosphere and impacts the Earth's
surface
• Its size can vary from big
boulders to tiny rocks
44. Black Hole
• Definition:
– It is an area in space where gravity is so
strong that even light cannot escape from
it. Since light cannot escape from a black
hole, it appears black
• A black hole is not really a hole and it
is not empty
• It is filled with a lot of material
crammed into an extremely small
space
45. • The term black hole is used because
these objects look like black holes in
space - since they put out no light
• How do black holes form?
– When a large star runs out of fuel it can no
longer support its heavy weight.
– The pressure from the star's massive layers of
hydrogen press down forcing the star to get
smaller and smaller and smaller.
– Eventually the star will get even smaller than
an atom.
– Imagine that for a moment, an entire star
squashed up into less space than a tiny atom
46. • If you make something smaller by
squishing it, its gravity becomes
much stronger. Imagine then, if
you squish a star into the size of an
atom how powerful its gravity
would become
• A black hole's gravity becomes so
powerful that anything, including
light that gets too close, gets
pulled in
48. Galaxy
Definition:
– A group of millions of stars that are
relatively near each other
• Most stars seem to be in one or
another galaxy
• Example:
– Earth's own star, the Sun, is in the
Milky Way galaxy
50. Light Year
Definition
– A light year is the distance between two
points in space that it would take light to
travel when the distance between the two
points in time are one year
51. • Light travels at 186,000 miles
every second
• How big is this number?
– Write 1 number/second for 8hrs a
day without stopping Would take 6
& 1/2 days to get to that number
– If you go back and fourth across the
U.S. 66 times with an average speed
of 60miles/hour Would take 1
year and 3weeks
52. •
•
•
•
1
1
1
1
year = 365 days
day = 24 hours
hour = 60 minutes
minute = 60 seconds
No. of seconds = 60 x 60 x 24 x 365
in 1 year
= 31,536,000 sec
53. Number of miles light travels
in one year
= 186,000 x 31,536,000
= 5,865,696,000,000 miles
54. • The closest star is 4 light years away
= 4 x 5,865,696,000,000
= 23,462,784,000,000 miles
• Edge of universe is 15 billion light
years away
• How far is it?