Download Earths Revolution

There are about 6000 visible stars in the night sky.
They are FAR. The light from our closest star, Proxima Centauri left 4 years ago!
Essential Question: What is the evidence/observations that show that the Earth orbits the Sun?
PHENOMENON:
What did you observe?
What evidence do you have?
OBJECTS:
Define the system.
What objects are interacting?
Mars appears to have retrograde motion
Venus has phases like the moon
Planets speed changes during orbit
Earth and Sun
MOTION/MODEL:
Describe the motion that in the model that
explains your observations
Heliocentric solar system
Copernicus: Earth and Mars orbit the sun at
different speeds;
Galileo: the Earth and Venus orbit the Sun
Kepler: The planets orbit the Sun and in elliptical
orbits. Distance and pull of gravity change speed.
ONLY Summer constellations:
ONLY Winter constellations:
Parallax
Summary Statement - Answer the Essential Question:
PHENOMENON:
OBJECTS:
MOTION:
Essential Question:
What is evidence
that
the
Earth
28.2
revolves around the Sun?
1. Galileo
2. Copernicus
3. Kepler
4. Constellations
5. Parallax
Galileo
Big Jupiter has several moons orbiting it!
Venus has phases, so the planets are
orbiting the Sun
Copernicus Explains Retrograde Motion
Planet's
apparent path
around sky.
6
6
5
5
4
3
Sun
1
Earth
3
2
2
Mars
orbit
4
1
Earth is ORBITING the Sun faster, to it overtakes slower
outer planets so they appear to slow down, move in reverse, and
then move forward again with respect to the fixed stars.
Fixed Stars
Kepler’s observations/measurements: the Sun
appeared to change diameter throughout the year
Earth has an
elliptical orbit
around the Sun
Not actually the
diameter
changing but the
distance the sun
is from the Earth
that changed
(perihelion: close
aphelion: far)
6
Other Evidence
Find constellations that ONLY appear in the Summer sky.
Find ones that ONLY appear in the Winter sky
Summer Constellations
Winter Constellation
As we revolve around the Sun, the night time Earth faces a
different direction in the sky at different months of the year,
so we see different constellations.
B
A
Parallax- the apparent shift in position of a star
when the Earth is orbiting (the Sun)
Stellar Parallax Interactive
http://highered.mheducation.com/olc
web/cgi/pluginpop.cgi?it=swf::800::6
00::/sites/dl/free/007299181x/78778/
Parallax_Nav.swf Stellar Parallax
Interactive
http://highered.mheducation.com/site
s/007299181x/student_view0/interact
ives.html#
If the distance to
the target star is
“close” then the
parallax shift will
appear to be
LARGE
E
PHENOMENON: OBJECTS:
What did you observe?
What evidence do you have?
The constellations that
are visible in the night
sky change throughout
the year.
The 12 zodiac
constellations change
each 12 month in a cycle.
The background of stars
behind a familiar
constellation changes
over several months
Define the system.
What objects are interacting?
Earth
Stars
MOTION:
Describe the motion that in the
model that explains your
observations
As the Earth orbits around the
Sun, the night side of the Earth
is a facing different part of the
sky and seeing different stars
(constellations).
Parallax: the apparent shift in
the position of stars because the
Earth has change to a different
location (the other side of the
Sun/solar system) and is now
viewing the stars from a
different angle.