Download presentation
Presentation is loading. Please wait.
Published byWilla Rich Modified over 8 years ago
1
Solar System: Sun, Earth and Moon
2
How to get to Mars
3
Earth’s size and shape The earth is sphere. Aristotle made three observations: Objects fall straight down Earth’s shadow is curved People see different stars
4
Earth
6
Gravity The attractive force between two objects Depends on the masses and distance between two objects. How does the pull of gravity indicate that the Earth’s shape is spherical?
7
Earths properties: Diameter Pole to Pole12,714 km Diameter through equator12,756 km Circumference poles40,008 km Circumference equator40,008 km Mass5.98 X 10 24 kg Avg distance from sun149,600,000km Avg distance from moon384,400 km Period of rotation23hr 56 min Period of revolution365 days, 6h,9min
8
Earth’s magnetic field Hypothesized that the strong rotation of the earth and the movement in the core set up the magnetic field The magnetic poles are 11.5* off from the physical poles. They wander due to the movement of the Earths crust and mantle
9
Magnetic fields http://www.google.com/i mgres?q=earths+magnetic +poles&hl=en&sa
10
Magnetosphere An area in the Earth’s magnetic field that deflects harmful radiation coming from the sun as solar wind These collide with atoms in the atmosphere causing the aurora borealis or aurora australis
12
Earth’s Orbit ellipse
13
http://scienceblogs.com/startswithabang/2010/10/counterclockwise_but_there_are.php
14
Earth Is a planet Supports life Has lower CO2 than Venus but trapped CO2 may contribute to green house effect Ocean absorbs CO2
15
If the magnetic field was not there to protect us what would happen to the earth?
16
The Sun and Earth: seasons The earth moves in two ways: Rotation: the earth spinning like a top around its axis. 24 hours or one day Revolution: The earth traveling around the sun. It takes one year 365 ¼ days
17
Rotation of the earth http://www.youtube.com/watch?v=knK87GoNyGo
18
Revolution of the earth
19
Where the sunlight hits the earth Slanted less intense at an angle Direct intense light Slanted less intense at an angle
20
Seasons Seasons are caused by the tilt of the Earth’s axis as it moves around the sun. The amount of sunlight depends on the Latitude that the sunlight is directly hitting.
21
Solstices Solstices occur twice a year on the days that the sun appears directly overhead at latitude 23.5 north or 23.5 south. Remember the earth tilts 23.5 degrees off of the axis. Northern Hemisphere: Summer solstice on June 21 st. The Northern Hemisphere is tilted toward the sun. The longest day in the North and the shortest in the South. North- Summer, South-Winter.
23
Solstice Winter solstice occurs on December 21 six months after the Summer Solstice. The Northern Hemisphere is tilted away from the sun and receives the least amount of light. Shortest day in the North and Longest day in the South. North-Winter, South-Summer
25
Equinoxes See page 754: Halfway between the solstices are two days called Equinoxes. At the Equinox neither hemisphere is tilted toward the sun the length of day light and night is EQUAL. March 22- Spring, September 22- autumn
26
Spring equinox is called Vernal equinox. Autumn equinox is called the Autumnal equinox. On these two days the sun is directly overhead the equator.
27
http://www.classzone.com/books/earth_science/ter c/content/visualizations/es0408/es0408page01.cfm http://www.classzone.com/books/earth_science/ter c/content/visualizations/es0408/es0408page01.cfm
28
Review What two ways does the earth move in space? What determines the change in seasons?
29
Solar eclipse
31
http://stargazerpaul.com/s_eclips.htm http://www.mreclipse.com /Special/image/SEDiagra m1c.JPG
32
Solar eclipse
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.