Solar System:
Sun, Earth and Moon
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

Earth
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?
Earths properties:
Diameter Pole to Pole
12,714 km
Diameter through equator
Circumference poles
12,756 km
40,008 km
Circumference equator
Mass
Avg distance from sun
40,008 km
5.98 X 1024 kg
149,600,000km
Avg distance from moon
384,400 km
Period of rotation
Period of revolution
23hr 56 min
365 days, 6h,9min
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.
 The wander due to the movement of the
Earths crust and mantle
Magnetic fields
http://www.google.com/i
mgres?q=earths+magnetic
+poles&hl=en&sa
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
Earth’s Orbit
ellipse
http://scienceblogs.com/startswithabang/2010/10/counterclockwise_but_there_are.php
Earth

Is a planet

Suports life

Has lower CO2 than Venus but trapped
CO2 may contribute to green house effect

Ocean absorbs CO2

If the magnetic field was not there to protect
us what would happen to the earth?
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 years 365 ¼ days
Rotation of the earth

http://www.youtube.com/watch?v=knK87GoNyGo
Revolution of the earth
Where the sunlight hits the
earth
slanted
Direct
slanted
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.
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 un
tilts 23.5 degrees off of the axis.

Northern Hemisphere: Summer solstice on
June 21st. The Northern Hemisphere is
tilted toward the sun. The longest day in the
North and the shortest in the South.

North- Summer, South-Winter.
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
VLA

Very Large Array (VLA)Dedicated in 1980, the Very Large Array
(VLA) has been an extraordinarily productive scientific instrument.
Astronomers from around the world use it to study objects from our
Solar System to the edges of the known Universe, billions of lightyears from the Earth.The telescope array consists of twenty-seven,
230-ton, 25-meter diameter dish antennas that together they
comprise a single radio telescope system.The VLA has made key
observations of black holes and protoplanetary disks around young
stars, discovered magnetic filaments and traced complex gas
motions at the Milky Way's center, probed the Universe's
cosmological parameters, and provided new knowledge about the
physical mechanisms that produce radio
Image courtesy of NRAO/AUI
EVLA

emission.The VLA is now being transformed into a new
research instrument: the Expanded Very Large Array (EVLA).
By 2012, new state-of-the-art electronics and software will have
completely transformed the VLA into the EVLA, a much more
capable research tool with more than ten times the VLA's
sensitivity. Reinvigorated by new technologies, the EVLA will
push the frontiers of science and knowledge for decades to
come.The Very Large Array Visitors Center is 50 miles west of
Socorro, New Mexico on U.S. Highway 60. From U.S. 60, turn
South on NM 52, then West on the VLA access road, which is
well marked. Signs will point you to the Visitor Center.