Download Earth from Space

Earth Science Notes
Earth from the Perspective of Space
Objectives
I can…
• Describe Earth’s place in the solar system, galaxy, and universe.
• Explain the effect that Earth’s tilt and orbital position have.
• Describes Earth’s orbital variations.
• Differentiate between solstices and equinoxes and explain what
causes them.
Earth from Space
If you could see the earth illuminated when you were in a place
as dark as night, it would look to you more splendid than the
moon.
— Galileo Galilei, Dialogue Concerning the Two Chief
World Systems, 1632.
How might looking at Earth from the perspective of space change the way we think? 
Write a response on the next slide.
How might looking at Earth from the perspective
of space change the way we think?
Your Response:
Astronauts view of the Earth in their own
Words
• ”I didn’t feel like a giant. I felt very, very small.”
- Neil Armstrong on looking back at the Earth from the Moon in July 1969.
• When you're finally up at the moon looking back on earth, all those differences and nationalistic
traits are pretty well going to blend, and you're going to get a concept that maybe this really is
one world and why can't we learn to live together like decent people.
— Frank Borman, Apollo 8
• To look out at this kind of creation out here and not believe in God is to me
impossible, ...
- John Glen, Mercury and Atlas Astronaut
• Oddly enough the overriding sensation I got looking at the earth was, my god that
little thing is so fragile out there.
— Mike Collins, Apollo 11 astronaut
Where Earth is in the Universe: Solar System
Where Earth is in the Universe: Galaxy
Where Earth is in the
Universe: Universe
The Milky Way Galaxy
Where
Earth is in
the
Universe
What Earth is doing as it moves through Space
Our Sun (and solar system)
revolves around the black hole
that is in the center of our galaxy
What Earth is doing as it moves through Space
As our
sun
revolves
around
the
center of
our
galaxy,
the Earth
revolves
around
our sun.
What Earth is doing as it moves through Space
• The Earth travels around the sun
on an oscillating ellipse.
What Earth is doing as it moves through Space
• Misconception: We experience winter when Earth gets farther from
the sun and summer when Earth gets closer to the sun. What does
the model below say?
What Earth is doing as it moves through Space
• As Earth revolves it
is tilted on its axis by
23.5°.
• This tilt is what is
responsible for the
seasons.
• The axis of rotation
points toward the
north star Polaris.
What Earth is doing as it moves through Space
We can see
how Earth is
spinning on
its axis by
examining
how the stars
in the sky
revolve
around the
north star
(Polaris).
What Earth is doing as it moves through Space
At different points
in its revolution,
Earth’s
hemispheres point
toward or away
from the sun.
Toward = summer
Away = Winter
What Earth is doing as it moves through Space
When the NH is tilted toward the sun it receives more direct sunlight,
therefore, we experience summer. When the NH is tilted away the
sunlight we receive is less intense because the same amount of light is
spread over a larger area of the Earth. This doesn’t heat as well.
What Earth is doing as it moves through Space
Notice:
• The middle latitudes
only get intense
sunlight for their
summer months.
• The latitudes near the
equator always have
some intense sunlight.
• What about the Artic
and Antarctic?
What Earth is doing as it moves through Space
• Due to the Earth’s tilt and the position of Earth in its orbit, the sun
appears to take different tracks across the sky during the course of a
Year.
What Earth is doing as it moves through Space
• During the Summer Solstice (June
21st) – the day in Earth’s revolution
where its axial tilt is most inclined
to the sun.
• The sun is the furthest north of the
equator – directly over the tropic of
Cancer.
• On this day the sun appears the
farthest north in the sky and also
appears higher in the sky than at any
other day of the year.
What Earth is doing as it moves through Space
• During the Winter Solstice
(December 21st) – the day in Earth’s
revolution where its axial tilt is
pointed away from the sun (in NH).
• The sun is the furthest South of the
equator – directly over the tropic of
Capricorn.
• On this day the sun appears the
farthest SOUTH in the sky and also
appears LOWER in the sky than at any
other day of the year.
What Earth is doing as it moves through Space
During the Equinoxes the
Sun is directly over the
equator.
This means equal amounts
of sunlight/daylight for the
North and South
Hemispheres.
What Earth is doing as it moves through Space
Comparison of the Sun’s path in the sky during solstice and equinoxes.
Historically, solstices and equinoxes have meant a lot to mankind.
• Vikings visited wells and made monetary sacrifices (money) during
the summer solstice.
• Wyoming’s Bighorn medicine wheel, an arrangement of stones built
several hundred years ago by the Plains Indians, aligns with the
solstice sunrise and sunset, and was the site of that culture’s annual
sun dance.
• Druids gathered at Stonehenge for the summer solstice, winter
solstice, spring equinox and autumn equinox.
Summary
Can I…
• Describe Earth’s place in the solar system, galaxy, and universe.
• Explain the effect that Earth’s tilt and orbital position have.
• Describes Earth’s orbital variations.
• Differentiate between solstices and equinoxes and explain what
causes them.