Transcript Solar System where_are_we

Where are we?
Milky Way
Galaxy
Because we dwell within the Milky Way Galaxy, it is
impossible for us to take a picture of its spiral structure
from the outside. But we do know that our Milky Way
has a spiral nature from observations made from
within our Galaxy (though whether or not it is a barred
spiral is still being debated). To represent this, the
beautiful spiral galaxy Messier 74 was used, as it
thought to be a similar galaxy to ours.
Left is a picture of the real Milky Way taken by
the satellite COBE. The disk and center region of
our Galaxy are readily recognizable. This image
makes the Milky Way appear much more galaxylike and less like the smudge of stars we see
stretching across our night sky. It is possible to
imagine what our Milky Way might look like
looking down on it from outside.
Where we are located within our galaxy.
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a spiral galaxy with large concentration of
stars in its nucleus
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Stars, dust, and gas fan out from the thick
center of the Galaxy in long spiraling arms
Our solar system is located on one of these
spiral arms, about 26,000 light years from
the center of the Galaxy
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All objects in the Galaxy revolve around the
Galaxy's center
Scientists have calculated that are about
400 billion stars in our galaxy
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Through a telescope the Milky Way galaxy
has been found to be made up of countless
individual stars that seem relatively close
together. This is because from the vantage
point of Earth we are looking at the Milky
Way on its edge and can't see where the
stars are actually located.
The Milky Way is part of a galaxy cluster that
includes 30 other galaxies, the closest of
which is the Andromeda Nebula.
Our Solar System
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Our sun is a medium large size star in our galaxy. It gives us heat and light.
Earth is the 3rd planet from the sun; about 93,000,000 miles away.
We are the 5th biggest planet in our system. Jupiter is the biggest.
Earth travels 595 million miles around the sun each year. Its orbit is an ellipse, which is
a long oval shape.
As it travels around the sun, it also rotates around its own axis. So, even though the
sun appears to be moving across the sky, it is our earth that is turning and moving
instead.
Seasons and Axis Tilt
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It seems as though the seasons are
caused by how far we are from the
sun.
In reality, it is how we are tilted
towards the sun that gives us our
seasons.
As the earth rotates around the earth,
it maintains the same angle of 23.5°.
The Northern and Southern
Hemispheres have opposite seasons
from each other. We will only discuss
the Northern Hemisphere where we
live.
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In summer, the sun’s rays hit the earth
at a more direct angle giving us a
warmer temperature and more hours
of light.
During winter, the rays hit the earth at •
a more extreme angle resulting in
cooler temperatures and fewer hours
of light.
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Solstices
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When the sun reaches its farthest northern and
southern delinations.
Summer Solstice is June 21st - longest day
Winter Solstice is December 21st – shortest day
Equinoxes
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When days are equal in hours per day.
Spring Equinox is approx. March 21st
Autumn Equinox is approx. September 21st
Pacing our Solar System
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