Upload
others
View
2
Download
0
Embed Size (px)
Citation preview
Movement of the Earth
Earth’s
Movemements
• astronomical unit: the average distance between the earth and the sun –150 million km
–93 million miles
Earth has 2 Movements:
Rotation: is the turning or spinning of a body on its axis
1) 1 rotation = 24 hours = 1 day
Rotation & Revolution
http://tm.wc.ask.com/r?t=c&s=p&id=30751&sv=za5cb0db1&uid=04D1F290C8103EF14&sid=1CDF54EA0CE2A5324&p=%2ftopimage&o=0&u=http://www.earthkam.ucsd.edu/public/students/resources/orbits/EarthSat.gifhttp://tm.wc.ask.com/r?t=c&s=p&id=30751&sv=za5cb0db1&uid=04D1F290C8103EF14&sid=1CDF54EA0CE2A5324&p=%2ftopimage&o=0&u=http://www.earthkam.ucsd.edu/public/students/resources/orbits/EarthSat.gif
What effect (that we see daily) does rotation cause?
DAY NIGHT & 2) Causes:
http://tm.wc.ask.com/r?t=c&s=p&id=30751&sv=z6f5372c3&uid=04D1F290C8103EF14&sid=1CDF54EA0CE2A5324&p=%2ftopimage&o=0&u=http://dogbert.gi.alaska.edu/ScienceForum/ASF6/images/693.jpghttp://tm.wc.ask.com/r?t=c&s=p&id=30751&sv=z6f5372f2&uid=04D1F290C8103EF14&sid=1CDF54EA0CE2A5324&p=%2ftopimage&o=0&u=http://www.opencourse.info/astronomy/introduction/03.motion_earth/earth_rotation.gif
3) is in the direction from West to East…
• Sun appears to be moving East to West
• Sunrise in East
& sunset in West
http://tm.an.ask.com/r?t=an&s=p&uid=04D1F290C8103EF14&sid=1CDF54EA0CE2A5324&qid=90C1834AC4B6EA489E965F7267FE5FDA&io=13&sv=za5cb793e&o=0&ask=compass&uip=d03f72b9&en=js&eo=0&pt=&ac=15&qs=31&pg=2&u=http://pictures.ask.com/redir?u=http%3a%2f%2flrs.ed.uiuc.edu%2fstudents%2ftbarcalow%2fQuilt%2fHattie%2fColorQuilt.htm&bpg=http%3a%2f%2fpictures.ask.com%2fpictures%3fq%3dcompass%26o%3d0%26page%3d2&q=compass&s=p&bu=http%3a%2f%2flrs.ed.uiuc.edu%2fstudents%2ftbarcalow%2fQuilt%2fHattie%2fColorQuilt.htm&qte=0&o=0&isimageSearch=true&fromImagePage=False&iskey=&thumbsrc=http%3a%2f%2fimages.picsearch.com%2fis%3f97897571787&imagesrc=http%3a%2f%2flrs.ed.uiuc.edu%2fstudents%2ftbarcalow%2fQuilt%2fHattie%2fcompass.gif&thumbwidth=128&thumbheight=123
Movement #2 … REVOLUTION
is Earth’s movement around the sun
Revolution cont.
1 Revolution= 365.24 days = 1 year
.24 x4 = 1 day Leap Year!
Speed of Revolution =30km/s=70,000 mph
ORBIT: is the path Earth follows
Earth’s Orbit is:
• Slightly elliptical (not a perfect circle)
• Earth is NOT always the same distance from the sun
PERIHELION
closest point to the sun at:
147 million km = (91.34 million miles)
and occurs on: Jan 3rd
PERI=near Helio=Sun
APHELION
farthest point from sun at:
152 million km =
94.45 million miles
And occurs on: July 4th
Ap=away Helio=Sun
Kepler’s Laws of Planetary Motion
• 1st law : planets orbit the sun in a path called an ellipse
aphelion
perihelion
• 2nd law: planets move fastest when they are closest to the sun in their orbits
• 3rd law: the farther away a planet orbits, the longer the planet takes to revolve around the sun
Tilt of Earth’s Axis
is 23.5 degrees
Always pointed toward North
Star
What effect does this cause?? seasons
http://tm.wc.ask.com/r?t=an&s=p&uid=04D1F290C8103EF14&sid=1E2F78E23AEAB5324&qid=702DF09C9F0EEC47AFF9D5F5EC1EAC89&io=4&sv=za5cb0d71&o=0&ask=tilt+of+earth&uip=d03f72b9&en=is&eo=0&pt=&ac=6&qs=1&pg=1&u=http://pictures.ask.com/redir?u=http%3a%2f%2fwww1.thny.bbc.co.uk%2fscience%2fspace%2fsolarsystem%2fearth%2fsolsticescience.shtml&bpg=http%3a%2f%2fpictures.ask.com%2fpictures%3fq%3dtilt%2bof%2bearth%26o%3d0%26page%3d1&q=tilt+of+earth&s=p&bu=http%3a%2f%2fwww1.thny.bbc.co.uk%2fscience%2fspace%2fsolarsystem%2fearth%2fsolsticescience.shtml&qte=0&o=0&isimageSearch=true&fromImagePage=False&iskey=&thumbsrc=http%3a%2f%2fimages.picsearch.com%2fis%3f508877961953&imagesrc=http%3a%2f%2fwww1.thny.bbc.co.uk%2fscience%2fspace%2fsolarsystem%2fimages%2fearth_tilt.jpg&thumbwidth=126&thumbheight=128
This causes the: Seasons! 1) Longest days & most direct sunlight=Summer
2) Shortest days and least direct sunlight=
Winter
What effect does this cause?? seasons
http://tm.wc.ask.com/r?t=an&s=p&uid=04D1F290C8103EF14&sid=1E2F78E23AEAB5324&qid=702DF09C9F0EEC47AFF9D5F5EC1EAC89&io=4&sv=za5cb0d71&o=0&ask=tilt+of+earth&uip=d03f72b9&en=is&eo=0&pt=&ac=6&qs=1&pg=1&u=http://pictures.ask.com/redir?u=http%3a%2f%2fwww1.thny.bbc.co.uk%2fscience%2fspace%2fsolarsystem%2fearth%2fsolsticescience.shtml&bpg=http%3a%2f%2fpictures.ask.com%2fpictures%3fq%3dtilt%2bof%2bearth%26o%3d0%26page%3d1&q=tilt+of+earth&s=p&bu=http%3a%2f%2fwww1.thny.bbc.co.uk%2fscience%2fspace%2fsolarsystem%2fearth%2fsolsticescience.shtml&qte=0&o=0&isimageSearch=true&fromImagePage=False&iskey=&thumbsrc=http%3a%2f%2fimages.picsearch.com%2fis%3f508877961953&imagesrc=http%3a%2f%2fwww1.thny.bbc.co.uk%2fscience%2fspace%2fsolarsystem%2fimages%2fearth_tilt.jpg&thumbwidth=126&thumbheight=128
Precession is: • the gravitational pull of the moon that
causes Earth’s axis to wobble and spin like a top
• Earth makes 1 full turn every 26,000 years
• North Star will NOT always be where North Pole points
Earth’s other movements
Precession: The axis points in different directions!
Nutation – the rocking or wiggling motion on the axis of rotation -Earth’s nutation period is 18.6 years
-The effect is a small change in Earth’s tilt towards the sun
- Result is a slight shift in location of: Tropic of Cancer, Tropic of Capricorn, Arctic Circle and Antarctic Circle
Barycenter – the point between 2 objects where they balance each other - The center of mass between 2 or more celestial bodies that orbit each other - Both bodies orbit around a point that is NOT the center of the larger body
http://www.youtube.com/watch?v=1iSR3Yw6FXo
http://www.youtube.com/watch?v=1iSR3Yw6FXo
Earth’s
circumference Video: Earth’s Equatorial Bulge
Video: Shape of
Earth
Earth’s
Circumference
http://geography.about.com/library/faq/blqzcircumference.htmhttp://geography.about.com/library/faq/blqzcircumference.htmhttp://www.youtube.com/watch?v=uXiRupBxI9Qhttp://www.youtube.com/watch?v=HGrgitTXhBYhttp://www.youtube.com/watch?v=HGrgitTXhBY