any object in space outside of earth's atmosphere stars, planets, moon, sun, comets model of...
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any object in space outsideof Earth's atmosphere
stars, planets, Moon, Sun, comets
model of the sky
zenith Z
- highest point in sky
- directly above the observer's head
horizon imaginary boundarybetween the sky and ground
Z
1. Looking up, the skyappears to be a ________
2. Watch a _______ rise. It moves in a wide _______.But one point in the sky____________________________________________________
3. Later the star ________.It is as if the stars moveon a ____________________that ____________________Earth on a ____________________. Half of the sphereis ______________________.
dome
stararc
does not move. That point appears fixed.
sets
transparent sphererotates around
giganticaxis
star
II. Star Motions.
hidden beneath you.
4. The fixed point that does notmove is directly above ________________________________. It isnear the star _________________. Its altitude above the horizonequals the __________________ ofthe observer.
5. Some stars _________ and_____. See A and B at right.Other stars ___________________________. They circle the____________ , and are called_______________________ stars.See star C at right .
A
BC
northon the horizon
Polaris
Polaris
latitude
riseset
never rise andnever set
pole/axiscircumpolar
Notice: -Star A is _______________________
-Most stars do NOT rise directly in the _________ and do NOT set directly in the ___________
-The latitude of this observer is ____________
Star C
350
circumpolar
350 N
eastwest
Which direction are you looking in this picture?
Which direction are you looking in this picture?
What latitude is this? How long was the exposure?
Stars appear to rotate around Earth from _______
to _________ at a rate of ________________
because of Earth's _________________________________
the spinning of Earthon its own axis
west
3600
243600
24 h
150 / hour
east
west 150 / hour
rotation in the opposite direction.
WEeast
circumpolar
2
3
4
= Polaris
N EW
1
NYmid October
234
Notice:_____ x 150/h= _________between eachposition above
6 h900
N
Sun's path
D. 1. The stars, Sun, moon and planets move ______/hacross the ________________________.
S
8 am
9 am
etc
150
150
celestial sphere
= celestial object
from to hours degrees
8 am 9 am 1
8 am 10 am
10 am 2 pm
9 am 2 pm
9 am 12 pm
10 am 4 pm
150
300
600
750
450
900
2
4
5
3
6
2. Because all stars move across the sky at _______________________ , any star with a ______________ path willbe above the horizon for ____________________________.
Star A: __________ path above horizon for _____ h
Star B: rises/sets in _______ above horizon for _____ h
Star C: __________ path above horizon for _______ h
NSA
B C
W
E
the samerate longer
a longer time
longest > 12
E/W___ 12
shortest < 12
1. ___________________. As Earth rotates on its axis, half of it faces the sun and has daylight. The other half is in darkness and has nighttime.
lightfromthe Sun
IV. Effects of Earth's Rotation
view from above North Pole:
Day Night
Night and Day
lightfromthe Sun
Earth rotates, so points on its surface rotate intoand out of _____________:
12 pm
6 pm
12 am
6 am
noon
sun
set
midnight
sun
rise
sunlight
8 am
Meridians shown are ______ apart every ______ hours(All times are approximate.)
10 am
2 pm
4 pm 8 pm
4 am
2 am
10 pm
View fromNorth Pole:
300 2
2. Time – is based on Earth's _________, which causes the Sun to _______ and _______
local meridian - __________________________________________________________________________
N
S
local noon- _______________________________________________________________________________
Sun's path
a.m. p.m.
Z
12 pm
E S W
rotationrise set
imaginary line from N to S passing through the zenith Z
12:00 p.m. -Sun is directly S - Sun is highest - looking south:
looking south
-points directly opposite the Sun-shortens in the a.m.-shortest at local noon and points N-lengthens in the p.m.
N
S
9 am3 pm
12 pm
pole
top view
S
N
9 am
pole
3 pm
noon
3. Change in Shadow Length.
shadow of a pole - ___________________________________________________________________________________________________________________________________
This is the basis of sundials.
4. Earth's Time Zones- Earth rotates _____ degrees every hour
- The Sun reaches local noon ______ degrees further__________ every hour
- Time zones are ______ apart from each other
1515
Eastern
CentralMountain
Pacific
2 pm1 pmnoon11 am
west150
V. Evidence of Earth's rotation:
1.Foucault Pendulum: ________________________ ________________________ ________________________ ________________________ ________________________ ________________________
A pendulum swungin one direction (A-A')appears to change to a new direction (B-B')because Earth rotates underneath it
B B'
Top view of pendulumat the North Pole:
___ hours later, Earth hasrotated ______ degrees:
A A' ____________________________________________
Notice thePendulumkeeps thesame direction
6
90
2. Coriolis Effect: ______________________________________________________________________________________________________________________________________
the apparent curving or turning of winds, currents and projectiles caused by Earth'srotation.
= original path
Turns tothe _______in NorthernHemisphere
direction of rotation
The equatormoves _________,than the poles.So projectilescurve _________of the _________path.
= curved path
Turns tothe _______in SouthernHemisphere
right
left
faster
in front original