Oblate Spheroid Bulges in the middle Earths Shape 1 Right distance from the Sun 2 Right amount of water 3 Right amount of atmosphere Why Does Earth Have Life The rotation of the Earth lasts for ID: 638697
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Slide1
EARTH
Space Unit Slide2
The Earth is not a true circle, it is a:
Oblate SpheroidBulges in the middle
Earth’s ShapeSlide3
1. Right distance from the Sun
2. Right amount of water3. Right amount of atmosphere
Why Does Earth Have Life?Slide4
The
rotation of the Earth lasts for 23hr 56min 4sec.
A rotation is the Earth turning around itself.
https://
www.youtube.com/watch?v=SsOJ0G1psUA
http://eoimages.gsfc.nasa.gov/images/imagerecords/57000/57760/rotate_320.mpg Earth’s RotationSlide5
A revolution is the path the Earth takes in the solar system around the Sun.
http://www.classzone.com/books/earth_science/terc/content/visualizations/es0408/es0408page01.cfm
2.42
https://
www.youtube.com/watch?v=UYaIQNjAX_8 Earth’s RevolutionSlide6
The revolution of the Earth around the Sun takes 365.25 days.
(which is why we have a leap year every 4 years)
Next Leap Year:
2020
Earth’s RevolutionSlide7
The Earth is
NOT perfectly vertical.It’s tilted! 23.4 degrees.
Earth’s TiltSlide8
Not only is the Earth tilted but it wobbles!!
http://en.wikipedia.org/wiki/Precession
Earth’s TiltSlide9
https://en.wikipedia.org/wiki/File:Precession_animation_small_new.gif
Precession in actionSlide10
The wobble changes which star is our North Star (Polaris to Vega)
This takes 26,000 years
Changing North StarSlide11
The tilt of the Earth and the Earth’s
revolution are the reason
we have seasons.
Earth’s Tilt and SeasonsSlide12
The seasons are a result of
two things:The
tilt
of the Earth
Earth’s location in its
revolution around the SunSeasonsSlide13
SeasonsSlide14
Vernal Equinox
(equinox=equal)March 21st
Equally
12 hrs
of light and 12 hrs of night.Seasons - SpringSlide15
Summer SolsticeJune 21
st 16hrs
of light and
8
hrs
of night.Seasons- SummerSlide16
Autumnal EquinoxSeptember 21
st 12
hrs
of light and 12
hrs of night.Seasons-FallSlide17
Winter SolsticeDecember 21
st 8
hrs
of light and 16
hrs of darkSeasons- WinterSlide18
If we did
not have a tilt in the Earth we would not
have seasons.
What would that be like?
http://
www.space.com/13068-seasons-change-space.html 2016http://
www.nasa.gov/multimedia/videogallery/index.html?media_id=161642931
SeasonsSlide19
sun is at its greatest
distance from the
celestial
equator solsticeSlide20
http://
astro.unl.edu/naap/motion1/animations/seasons_ecliptic.swf