Transcript Physics 1 - Origin of the Solar System

GCSE Science
Chapter 12
Origin of the Solar
System
GCSE Science
Chapter 12
Origin of the Solar System
The solar system was formed by a gravitational
fall of a cloud of gas made up of hydrogen,
helium and dust.
Next
Orbit of the Planets 1
GCSE Science
Chapter 12
Mercury
Earth
Venus
Mars
• The four inner planets are rocky.
• They are kept in an orbit around the
sun by gravity.
Orbit of the Planets 2
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Chapter 12
Jupiter
Uranus
Saturn
Neptune
• The other planets are gas giants.
• Pluto is no longer considered to be a planet!
GCSE Science
Chapter 12
Comets
• A comet’s orbit is an ellipse shape.
• The comet’s tail always points away from the sun - why?
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Chapter 12
MERCURY
 No atmosphere.
 Closest to the sun.
 Daytime
temperature
350°C.
 Night time
temperature 180°C.
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Chapter 12
Venus
 Thick and dense
atmosphere made
up of sulphuric
acid and carbon
dioxide.
 Severe
greenhouse effect.
 No life.
 No moon.
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Chapter 12
EARTH
• Blue planet with
clouds.
• Oxygen and water
available.
• Inhabited by life
forms.
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Chapter 12
MARS
 Rocky with red
dust on its surface.
 May once have
had water
 No life found here
so far.
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Chapter 12
JUPITER
 The largest
planets (all the
other planets
would fit into this
one!).
 Atmosphere of
liquid hydrogen
and helium.
SATURN
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Rings of small
rocks encased in
ice.
URANUS
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 Pale green colour.
 Looks as if it’s
lying on its side (it
has a horizontal
axis).
NEPTUNE
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 Similar to Uranus.
 Blue in colour.
PLUTO
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 Not considered to
be a planet any
longer.
 About 1/5 of the
size of the Earth.
Asteroids


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Chapter 12

There is an asteroid
belt between Mars
and Jupiter.
These are bits of
rock of varying
sizes.
These are affected
by the gravitational
pull of the planets,
and some have
even collided with
earth!
GCSE Science
Chapter 12
Comets
 Made up of a mixture
of ice and dust.
 Come from two
places: Oort cloud
(beyond the solar
system), and the
Kuiper belt (beyond
Neptune).
 They have elliptical
orbits.
 Tails always point
away from the sun
and are millions of
kilometres long!
GCSE Science
Chapter 12
Relative sizes
Data on the Solar System
Planet
Orbit (Years)
Average
Temperature
(°C)
4900
58
0.24
350
You are not expected to learn this
Venus
12000
108
0.62
information,
but
you will
need to450
Earth
150
15
use12800
the data to
draw a1.00
conclusion
Mars
228
1.88
-30
e.g. 6800
…..
Jupiter
143000
780
12.00
-150
Saturn
120000
1430
29.00
-180
Uranus
52000
2800
84.00
-210
Neptune
49000
4500
165.00
-220
Pluto
3000
5900
248.00
-230
Mercury
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Distance
Diameter (km) from the Sun
(km×106)
Temperature Difference
CONCLUSION:
500
The average temperature of the planets decreases with
their distance from the sun. Venus is an exception due to
the greenhouse effect. The change is not constant.
400
Average Temperature
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300
200
100
0
0
1000
2000
3000
4000
-100
-200
-300
Distance form the Sun (million km)
5000
6000
7000
CONCLUSION:
The time it takes for planets to orbit the sun increases
with distance. The change is not constant.
Amser Orbit
300
Amser Orbit (Blwyddyn)
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250
200
150
100
50
0
0
1000
2000
3000
4000
Pellter o'r Haul (miliwn km)
5000
6000
7000
GCSE Science
Chapter 12
GRAVITY
 Gravity is the force that exists between two or more masses.
 Gravitational force always attracts mass.
 Approximately 1/1,000,000 N exists between you and the
person next to you (it’s not strong enough to affect us).
Gravity
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A
The earth has a lot of mass, so its gravitational
attraction on our bodies keeps us on the ground.
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Chapter 12
GRAVITY
 Gravity is the force that keeps the planets in orbit around
the sun.
 Gravity i the force that keeps the moon (the earth’s
natural satellite) in its orbit around the earth.
 Gravity is the force that keeps satellites in their orbits
around the earth.
 Gravity always act on the centre of a mass.
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Chapter 12
GRAVITY
If it’s possible to fire a gun quickly enough, then the
gravitational force that pulls the bullet down towards the
centre of the earth, causes it to orbit around the earth.
GRAVITY - SUMMARY
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Chapter 12
Gravity meter
 A small body keeps in orbit around a larger body because of its high
mass, and the gravitational force between the two bodies.
 The larger the distance between the two bodies, the weaker the
gravitational force .
 The greater the mass, the greater the gravity.
DISCOVERING NEW PLANETS
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Chapter 12
The effect of another
planet’s gravity
 A planet’s orbit is something that can be predicted, but
sometimes a planet shows a change in its path. Sometimes,
the gravitational pull of another planet affects its path.
 We have been able to use this sin our search for new
planets.
 April 24, 2007 – a planet similar to earth, 20.5 light years
away, was found, with a larger gravity (1.6 more than earth).