Transcript chapter 1 section 2

The
Earth
in
Space`The Earth in Space
The Solar System
Our solar system consists of nine
planets ( now eight)
 Earth is the third planet from the sun
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Solar System
Every planet travels on a path known
as their ORBIT.
 An orbit is a elliptical shape (stretched
out circle)
 Every planet takes a different amount
of time to complete their orbit
 Earth takes 365 ¼ days to go around
the sun once.
The Planets
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Earth like Planets
 Mercury
 Venus
 Mars
 Pluto
Solid
Small
No or few moons
Spin slowly
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Jupiter like Planets
 Jupiter
 Saturn
 Neptune
 Uranus
Balls of gas
Spin rapidly
Many moons
Surrounding rings
The Sun
93 million miles away from earth
 Made of hot gases
 Temperature – 27 million degrees
Fahrenheit
 The sun gives off the light and warmth
without it life would not exist.
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The Sun and the Seasons
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The earth is tilted on an angle of 23 ½ degrees
on its axis
Due to this tilt we get the four seasons (diagram
on page 31 in your book)
As the earth orbits around the sun, the sun light
hits the northern and southern hemispheres
differently
When the sun is hitting the hemisphere directly
then you are receiving strong rays and the
warmth of summer
Slanted rays means that it is winter
Summer Solstice
Summer Solstice – June 21st North Pole
is tilted toward the sun and at noon at the
Tropic of Cancer the sun is directly
overhead.
-In Northern hemisphere only
- longest day of sunlight fewest hours
of darkness
-In Southern Hemisphere it is the
beginning of winter
Winter Solstice
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Winter Solstice – December 22 North Pole is
tilted away from the sun and the at noon the sun
is overhead at the Tropic of Capricorn
 In Northern Hemisphere only
 This is the day with the shortest hours of
daylight and longest hours of darkness.
 This day is the beginning of summer in
the southern hemisphere
Spring & Fall Equinoxes
Spring Equinox – Vernal Equinox –
March 22
 Fall Equinox – Autumnal Equinox September 23
 Midway between the two solstice
 The days and nights are of equal lenghts.
 On both of these days the moon shines
directly over the equator
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The Sun
The Earth
Third planet from the sun
 Has only 1 moon compared to Jupiter who
as the most of any planet, and Mercury
and Venus which have no moons
 The earth is 75% water 25% land
 Consists of 7 continents
 Only planet thus far that has life on it
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Composition of the Earth
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Core- inner core- solid
Outer core- liquid- iron
Mantle – middle layer
between the crust and the
core
Crust – outermost layer,
25 miles thick beneath
the continents
Light and brittle layer
Earth’s Movement
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Like all other planets, earth spins on its axis –
the imaginary line that runs through the
earths center between the north and south
poles.
Earth takes 24 hours to spin fully around on its
axis thus we have 24 hour days.
As the earth turns on its axis it has part of the
planet facing the sun where it is daytime an part
turned from the sun where it is night time.
Earth’s Movement Con’t
The earth revolves around the sun as it
rotates on its axis. This revolution
around the sun takes 365 ¼ days.
 The revolution around the sun is what we
call 1 year.
 The extra ¼ of the year is added up and
gives us a leap year.
 Leap year is always February 29th.
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The Atmosphere
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The atmosphere is the gaseous envelope surrounding
the earth.
It consists mainly of nitrogen and oxygen
Life on earth depends partly on the atmosphere
There are 5 layers
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Troposphere – where all weather occurs (people, plants and
animals live here)
Stratosphere – goes into the sky and is the ozone layer
Mesosphere – above the earths surface
Thermosphere – gets higher the further you go because it gets
closer to the sun
Exosphere – furthest layer of the atmosphere together with the
thermosphere make the upper atmosphere
The Atmospheres Purpose
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Contains 99% nitrogen and oxygen which is
needed for life
Holds in the suns heat in order to keep life
(greenhouse) without the atmosphere earth
would be too cold for many things to live
Reflects some heat back into the atmosphere
keeping the earth from becoming too warm
Shields dangerous sun rays
The Planets
Mercury
Mercury
Closest planet to the sun
 1/3 the size of the earth (2nd smallest
planet, now the smallest)
 It has no moons
 Length of year is 88 days
 800 degrees in the daytime, -300 degrees
in the night time
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Venus
Venus
2nd planet from the sun
 Sixth largest (slightly smaller than earth)
 Sometimes known as earth’s sister planet
because they are similar in size, density,
and volume.
 Has a very slow rotation 243 earth days
per venus days.
 Temperature 900 degrees Fahrenheit
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Earth
Earth
365 ¼ days per year
 Only planet with life
 Varying temperatures
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Mars
Mars
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The Red Planet
Contains the largest mountain in the solar
system
4th planet from the sun
7th largest planet
½ the size of the earth
1 day on Mars is 24 hours just like EARTH!
2 tiny moons
Jupiter
Jupiter
5th planet from the sun
 By far the largest planet more than twice
the size of all the planets combined
 4 very large moons
 Gas planet – 90% hydrogen, 10%helium
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Saturn
Saturn
2nd largest planet in the solar system
 6th planet from the sun
 Length of year is equal to 29.42 earth
years
 Days are 10 h and 39.4 minutes long
 Gas planet
 Has a series of rings around it
 33 moons
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Saturn’s Rings
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Ring Name: D
Distance*: 67000 km
Width: 7,500 km Ring Name: B
Distance*: 92000 km
Width: 25,500 km
Thickness: 0.1 km - 1 km
Mass: 0.1 kg
Albedo: 0.65
Ring Name: A
Distance*: 122200 km
Width: 14,600 km
Thickness: 0.1 km - 1 km
Mass: 0.1 kg
Albedo: 0.60
Ring Name: F
Distance*: 140210 km
Width: 30 km - 500 km
Ring Name: G
Distance*: 165800 km
Width: 8,000 km
Thickness: 100 km - 1,000 km
Mass: 100 kg
Ring Name: E
Distance*: 180000 km
Width: 300,000 km
Thickness: 1,000 km
Mass: 1,000 kg
Uranus
Uranus
7th planet from the sun
 3rd largest planet
 27 moons
 Ring system surrounding it
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Neptune
Neptune
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8th planet from the sun
4th largest
Composition – various ices and rock
Bluish color comes from methane gas
Crosses orbits with pluto at times making it the
farthest planet from the sun for several months.
13 moons
Has rings but they are not as bright and colorful
as Saturn’s because they are made of rock and
dust mostly
Pluto
Pluto
9th planet from the sun
 Smallest planet
 Pluto has just recently been taken off of
the list of the planets and made into a
dwarf planet due to its small size
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ERIS