Due
to the earth’s rotation, stars appear to move.
As the Earth rotates from west to east, the stars appear to
rise in the East, moving across south to set in the west.
The Sun will appear to move through the stars, making one
complete circuit of the sky in 365 days.
Stars
form patterns in the sky and are referred to as constellations.
It is these patterns that the ancient Greeks used to tell
stories of mythology and their gods.
There are 88 constellations that make up the sky.
The earth is tilted
23.5 degrees off the vertical. This
not only gives us the seasons but also changes which constellations we
see. Those constellations
that we can see year round are called circumpolar.
These constellations all circle the North Star and because we
live in the Northern Hemisphere, we see them all year round.
These constellations are: Ursa Major, Cassiopeia, Ursa Minor,
and Cygnus the Swan.
Vocabulary:
Year:
the time it takes for a planet to go all the way around the Sun ex:
on Earth a year is 365 days.
Axis:
a straight line that an object or body rotates, or seems to rotate
around.
Annual
Motion: the Earth’s orbital motion around the Sun every
year.
Rotation:
the motion of a planet, satellite or the Sun around its north-south
axis. It takes 24 hours
for the Earth to rotate once on its axis.
Equator:
an imaginary circle around the center of the Earth, perpendicular
to the axis of rotation.
Questions:
1.
What is the imaginary straight line that an object seems to rotate
around?
2.
What is the motion in which a planet or satellite moves around another
celestial object?
3.
What is the imaginary line that circles the center of the
Earth?
4.Tell
two new pieces of info that you learned from the links provided
concerning this topic. Insert these into your defense log.
