seasons on earth - weeblywatsonscience.weebly.com/.../4/8/5548081/seasons_on... · investigation 3:...
TRANSCRIPT
FOSS Planetary Science Course
© The Regents of the U
niversity of CaliforniaCan be duplicated for classroom
or workshop use.
FOSS Planetary Science Course
© The Regents of the U
niversity of CaliforniaCan be duplicated for classroom
or workshop use.
Investigation 3: SeasonsN
o. 15—N
otebook Master
Investigation 3: SeasonsN
o. 15—N
otebook Master
Wh
at do you im
agine w
hen
you read
these
word
s: sum
mer, sprin
g, fall, win
ter?
Most of u
s come up
with
a men
tal picture
or two. Su
mm
er mean
s shorts an
d T-sh
irts,
swim
min
g, and
fresh fru
its and
vegetables.
Win
ter mean
s heav
y coats and
short
days, p
erhap
s with
a blanket of sn
ow on
everythin
g. Seaso
ns are pretty easy to tell
apart in
most p
arts of the U
nited
States. Th
e
amou
nt of d
aylight, th
e average temp
erature,
and
the beh
aviors of plants an
d an
imals are
a few fam
iliar ind
icators of the season
. But
wh
at causes th
e predictable ch
ange of season
?
Wh
at have you
learned
in class th
at help
s
you explain
the reason
s for the season
s?
As E
arth
TiltsLet’s start w
ith a qu
ick review of som
e basic
inform
ation about Earth
.
Earth sp
ins on
an im
aginary axle called
an a
xis. T
he axis p
asses throu
gh th
e North
and
South Poles. T
his sp
inn
ing on
an axis is
called ro
tatio
n. It takes 24 h
ours for Earth
to make on
e complete rotation
.
Earth travels arou
nd
(orb
its) the Su
n.
Traveling arou
nd
someth
ing is called
revolu
tion
. Earth’s p
ath arou
nd
the Su
n
is not exactly rou
nd
. It is slightly oval. O
ne
revolution takes 365 an
d 1/4 d
ays, wh
ich w
e
call 1 year.
Seasons on Earth
Make a n
oteb
oo
k entry. R
ecord
the reaso
ns fo
r season
s on
Earth. Y
ou
can
add
mo
re after readin
g th
is article, bu
t record
you
r first ideas n
ow
.
10
Wh
at do you im
agine w
hen
you read
these
word
s: sum
mer, sprin
g, fall, win
ter?
Most of u
s come up
with
a men
tal picture
or two. Su
mm
er mean
s shorts an
d T-sh
irts,
swim
min
g, and
fresh fru
its and
vegetables.
Win
ter mean
s heav
y coats and
short
days, p
erhap
s with
a blanket of sn
ow on
everythin
g. Seaso
ns are pretty easy to tell
apart in
most p
arts of the U
nited
States. Th
e
amou
nt of d
aylight, th
e average temp
erature,
and
the beh
aviors of plants an
d an
imals are
a few fam
iliar ind
icators of the season
. But
wh
at causes th
e predictable ch
ange of season
?
Wh
at have you
learned
in class th
at help
s
you explain
the reason
s for the season
s?
As E
arth
TiltsLet’s start w
ith a qu
ick review of som
e basic
inform
ation about Earth
.
Earth sp
ins on
an im
aginary axle called
an a
xis. T
he axis p
asses throu
gh th
e North
and
South Poles. T
his sp
inn
ing on
an axis is
called ro
tatio
n. It takes 24 h
ours for Earth
to make on
e complete rotation
.
Earth travels arou
nd
(orb
its) the Su
n.
Traveling arou
nd
someth
ing is called
revolu
tion
. Earth’s p
ath arou
nd
the Su
n
is not exactly rou
nd
. It is slightly oval. O
ne
revolution takes 365 an
d 1/4 d
ays, wh
ich w
e
call 1 year.
Seasons on Earth
Make a n
oteb
oo
k entry. R
ecord
the reaso
ns fo
r season
s on
Earth. Y
ou
can
add
mo
re after readin
g th
is article, bu
t record
you
r first ideas n
ow
.
10
FOSS
Pla
neta
ry S
cien
ce C
ours
e©
The
Reg
ents
of t
he U
nive
rsity
of C
alifo
rnia
Can
be d
uplic
ated
for c
lass
room
or w
orks
hop
use.
FOSS
Pla
neta
ry S
cien
ce C
ours
e©
The
Reg
ents
of t
he U
nive
rsity
of C
alifo
rnia
Can
be d
uplic
ated
for c
lass
room
or w
orks
hop
use.
Inve
stig
atio
n 3:
Sea
sons
No.
16—
Not
eboo
k M
aste
rIn
vest
igat
ion
3: S
easo
nsN
o. 1
6—N
oteb
ook
Mas
ter
Eart
h i
sn’t
str
aigh
t up
an
d d
own
on
its
axis
as
it r
evol
ves
arou
nd
th
e Su
n. I
t is
til
ted
at a
23.
5° a
ngl
e.
Th
e av
erag
e d
ista
nce
bet
wee
n t
he
Sun
and
Ear
th i
s ab
out
150
mil
lion
kil
omet
ers
(km
). E
arth
’s o
rbit
is
slig
htl
y ov
al, s
o
Eart
h i
s so
met
imes
far
ther
aw
ay f
rom
an
d
som
etim
es c
lose
r to
th
e Su
n. T
his
dis
tan
ce
is s
o in
sign
ific
ant
that
it i
s n
ot r
elat
ed t
o th
e
seas
ons.
It w
ould
see
m lo
gica
l th
at s
um
mer
wou
ld
be w
hen
Ear
th i
s cl
oses
t to
th
e Su
n. T
hat
idea
is
wro
ng.
Eac
h y
ear
wh
en E
arth
is
clos
est
to t
he
Sun
, th
e N
orth
ern
Hem
isph
ere
exp
erie
nce
s w
inte
r. T
he
reas
ons
for
the
seas
ons
are
lin
ked
to
Eart
h’s
til
t, n
ot t
he
dis
tan
ce f
rom
th
e Su
n.
Th
ink
abou
t Ea
rth
rev
olvi
ng
arou
nd
th
e
Sun
. As
Eart
h r
evol
ves,
it a
lso
rota
tes
on it
s
axis
, on
e ro
tati
on e
very
24
hou
rs. H
ere’
s
som
eth
ing
imp
orta
nt:
Ear
th’s
Nor
th P
ole
poi
nts
tow
ard
a r
efer
ence
sta
r ca
lled
th
e
No
rth
Sta
r. N
o m
atte
r w
her
e Ea
rth
is
in it
s
orbi
t ar
oun
d t
he
Sun
, th
e N
orth
Pol
e p
oin
ts
tow
ard
th
e N
orth
Sta
r, d
ay a
nd
nig
ht,
eve
ry
day
all
yea
r.
Fall
equ
ino
x
Win
ter
sols
tice
Earl
y Ju
ly,
152
mill
ion
km
Earl
y Ja
nu
ary,
14
7 m
illio
n k
m
Sum
mer
so
lsti
ce
Spri
ng
eq
uin
ox
Sid
e-vi
ew d
iag
ram
of
Eart
h-S
un
re
lati
on
ship
, sh
ow
ing
sea
son
s in
th
e N
ort
her
n H
emis
ph
ere.
(N
ot
dra
wn
to
sca
le.)
No
rth
Sta
r
Is E
arth
clo
ser
to t
he
Sun
in
win
ter
or
in s
um
mer
? Is
dis
tan
ce f
rom
th
e Su
n a
re
aso
n f
or
seas
on
s o
n E
arth
?
N
N
N
N
Inve
stig
atio
n 3
: Se
ason
s 1
1
Eart
h i
sn’t
str
aigh
t up
an
d d
own
on
its
axis
as
it r
evol
ves
arou
nd
th
e Su
n. I
t is
til
ted
at a
23.
5° a
ngl
e.
Th
e av
erag
e d
ista
nce
bet
wee
n t
he
Sun
and
Ear
th i
s ab
out
150
mil
lion
kil
omet
ers
(km
). E
arth
’s o
rbit
is
slig
htl
y ov
al, s
o
Eart
h i
s so
met
imes
far
ther
aw
ay f
rom
an
d
som
etim
es c
lose
r to
th
e Su
n. T
his
dis
tan
ce
is s
o in
sign
ific
ant
that
it i
s n
ot r
elat
ed t
o th
e
seas
ons.
It w
ould
see
m lo
gica
l th
at s
um
mer
wou
ld
be w
hen
Ear
th i
s cl
oses
t to
th
e Su
n. T
hat
idea
is
wro
ng.
Eac
h y
ear
wh
en E
arth
is
clos
est
to t
he
Sun
, th
e N
orth
ern
Hem
isph
ere
exp
erie
nce
s w
inte
r. T
he
reas
ons
for
the
seas
ons
are
lin
ked
to
Eart
h’s
til
t, n
ot t
he
dis
tan
ce f
rom
th
e Su
n.
Th
ink
abou
t Ea
rth
rev
olvi
ng
arou
nd
th
e
Sun
. As
Eart
h r
evol
ves,
it a
lso
rota
tes
on it
s
axis
, on
e ro
tati
on e
very
24
hou
rs. H
ere’
s
som
eth
ing
imp
orta
nt:
Ear
th’s
Nor
th P
ole
poi
nts
tow
ard
a r
efer
ence
sta
r ca
lled
th
e
No
rth
Sta
r. N
o m
atte
r w
her
e Ea
rth
is
in it
s
orbi
t ar
oun
d t
he
Sun
, th
e N
orth
Pol
e p
oin
ts
tow
ard
th
e N
orth
Sta
r, d
ay a
nd
nig
ht,
eve
ry
day
all
yea
r.
Fall
equ
ino
x
Win
ter
sols
tice
Earl
y Ju
ly,
152
mill
ion
km
Earl
y Ja
nu
ary,
14
7 m
illio
n k
m
Sum
mer
so
lsti
ce
Spri
ng
eq
uin
ox
Sid
e-vi
ew d
iag
ram
of
Eart
h-S
un
re
lati
on
ship
, sh
ow
ing
sea
son
s in
th
e N
ort
her
n H
emis
ph
ere.
(N
ot
dra
wn
to
sca
le.)
No
rth
Sta
r
Is E
arth
clo
ser
to t
he
Sun
in
win
ter
or
in s
um
mer
? Is
dis
tan
ce f
rom
th
e Su
n a
re
aso
n f
or
seas
on
s o
n E
arth
?
N
N
N
N
Inve
stig
atio
n 3
: Se
ason
s 1
1
FOSS Planetary Science Course
© The Regents of the U
niversity of CaliforniaCan be duplicated for classroom
or workshop use.
FOSS Planetary Science Course
© The Regents of the U
niversity of CaliforniaCan be duplicated for classroom
or workshop use.
Investigation 3: SeasonsN
o. 17—N
otebook Master
Investigation 3: SeasonsN
o. 17—N
otebook Master
Tilt Eq
uals S
easo
nLo
ok at the illu
stration on
page 11. It sh
ows
wh
ere Earth is in
its orbit aroun
d th
e Sun
at
each season
. You w
ill also see that th
e North
Pole poin
ts toward
the N
orth Star in
all four
seasons.
Stud
y the Earth
diagram
in th
e sum
mer
solstice p
osition. B
ecause of th
e tilt, the
North
Pole is “leanin
g” toward
the Su
n.
Wh
en th
e North
Pole is leanin
g toward
the
Sun
, dayligh
t is longer, an
d th
e angle at
wh
ich ligh
t hits th
at part of Earth
is more
direct. B
oth of th
ese factors result in
more
sola
r energ
y fallin
g on th
e North
ern
Hem
isphere. It is su
mm
er even th
ough
Earth
is actually farth
er from th
e Sun
. (An
d w
hen
it
is sum
mer in
the N
orthern
Hem
isphere, it is
win
ter in th
e Southern
Hem
isphere.)
Look at th
e position
of Earth 6 m
onth
s
later (at win
ter solstice). Now
the op
posite
is true. Even
thou
gh Earth
is closer to the
Sun
at this tim
e, the N
orthern
Hem
isphere
is tilted aw
ay from th
e Sun
. Dayligh
t hou
rs
are shorter, an
d su
nligh
t does n
ot come as
directly to th
e North
ern H
emisph
ere, so
it gets less solar energy. It is w
inter in
the
North
ern H
emisph
ere.
Four d
ays in th
e year have n
ames based
on Earth
’s location
aroun
d th
e Sun
. In th
e
North
ern H
emisph
ere, sum
mer solstice is
Jun
e 21 or 22, wh
en th
e North
Pole tilts
toward
the Su
n. W
inter solstice is D
ecember
21 or 22, wh
en th
e North
Pole tilts away
from th
e Sun
.
Th
e 2 days w
hen
the Su
n’s rays sh
ine
straight dow
n on
the equ
ator are the
equ
inox
es. On
these 2 d
ays, Earth’s axis is
tilted n
either aw
ay from n
or toward
the Su
n.
Equinox mean
s “equal n
ight.” D
aylight an
d
darkn
ess are equal (or n
early equal) all over
Earth. T
here are tw
o equin
oxes each year,
the sprin
g (also called vern
al) equin
ox in
March
and
the fall (also called
autum
nal)
equin
ox in Sep
tember.
12
Tilt Eq
uals S
easo
nLo
ok at the illu
stration on
page 11. It sh
ows
wh
ere Earth is in
its orbit aroun
d th
e Sun
at
each season
. You w
ill also see that th
e North
Pole poin
ts toward
the N
orth Star in
all four
seasons.
Stud
y the Earth
diagram
in th
e sum
mer
solstice p
osition. B
ecause of th
e tilt, the
North
Pole is “leanin
g” toward
the Su
n.
Wh
en th
e North
Pole is leanin
g toward
the
Sun
, dayligh
t is longer, an
d th
e angle at
wh
ich ligh
t hits th
at part of Earth
is more
direct. B
oth of th
ese factors result in
more
sola
r energ
y fallin
g on th
e North
ern
Hem
isphere. It is su
mm
er even th
ough
Earth
is actually farth
er from th
e Sun
. (An
d w
hen
it
is sum
mer in
the N
orthern
Hem
isphere, it is
win
ter in th
e Southern
Hem
isphere.)
Look at th
e position
of Earth 6 m
onth
s
later (at win
ter solstice). Now
the op
posite
is true. Even
thou
gh Earth
is closer to the
Sun
at this tim
e, the N
orthern
Hem
isphere
is tilted aw
ay from th
e Sun
. Dayligh
t hou
rs
are shorter, an
d su
nligh
t does n
ot come as
directly to th
e North
ern H
emisph
ere, so
it gets less solar energy. It is w
inter in
the
North
ern H
emisph
ere.
Four d
ays in th
e year have n
ames based
on Earth
’s location
aroun
d th
e Sun
. In th
e
North
ern H
emisph
ere, sum
mer solstice is
Jun
e 21 or 22, wh
en th
e North
Pole tilts
toward
the Su
n. W
inter solstice is D
ecember
21 or 22, wh
en th
e North
Pole tilts away
from th
e Sun
.
Th
e 2 days w
hen
the Su
n’s rays sh
ine
straight dow
n on
the equ
ator are the
equ
inox
es. On
these 2 d
ays, Earth’s axis is
tilted n
either aw
ay from n
or toward
the Su
n.
Equinox mean
s “equal n
ight.” D
aylight an
d
darkn
ess are equal (or n
early equal) all over
Earth. T
here are tw
o equin
oxes each year,
the sprin
g (also called vern
al) equin
ox in
March
and
the fall (also called
autum
nal)
equin
ox in Sep
tember.
12
FOSS
Pla
neta
ry S
cien
ce C
ours
e©
The
Reg
ents
of t
he U
nive
rsity
of C
alifo
rnia
Can
be d
uplic
ated
for c
lass
room
or w
orks
hop
use.
FOSS
Pla
neta
ry S
cien
ce C
ours
e©
The
Reg
ents
of t
he U
nive
rsity
of C
alifo
rnia
Can
be d
uplic
ated
for c
lass
room
or w
orks
hop
use.
Inve
stig
atio
n 3:
Sea
sons
No.
18—
Not
eboo
k M
aste
rIn
vest
igat
ion
3: S
easo
nsN
o. 1
8—N
oteb
ook
Mas
ter
Day a
nd
Nig
ht
We
take
day
an
d n
igh
t fo
r gr
ante
d. T
hey
alw
ays
hap
pen
. Ear
th r
otat
es o
n it
s ax
is, a
nd
the
Sun
ap
pea
rs t
o ri
se; t
hen
th
e Su
n a
pp
ears
to s
et. T
his
cyc
le h
as h
app
ened
at
leas
t as
lon
g as
hu
man
s h
ave
been
on
Ear
th. I
t w
ill
mos
t li
kely
con
tin
ue
for
mil
lion
s of
yea
rs.
Bec
ause
Ear
th i
s ti
lted
, th
e le
ngt
h o
f
day
an
d n
igh
t fo
r an
y on
e pl
ace
on E
arth
chan
ges
as t
he
year
pas
ses.
Th
is t
able
sh
ows
how
hou
rs o
f d
ayli
ght
chan
ge a
t d
iffe
ren
t
lati
tude
s du
rin
g th
e ye
ar. W
hen
it’s
su
mm
er
in t
he
Nor
ther
n H
emis
pher
e, t
he
Nor
th P
ole
tilt
s to
war
d t
he
Sun
. Du
rin
g th
is t
ime
at t
he
Nor
th P
ole,
th
e Su
n n
ever
set
s. A
bove
th
e
Arc
tic
Cir
cle
(66.
5° n
orth
), d
ayli
ght
can
last
up t
o 24
hou
rs o
f th
e d
ay i
n t
he
sum
mer
.
Dar
knes
s ca
n la
st u
p t
o 24
hou
rs o
f th
e d
ay
duri
ng
the
win
ter.
Thin
k Q
uest
ion
sG
o ba
ck t
o yo
ur
not
eboo
k en
try
abou
t
the
reas
ons
for
the
seas
ons
that
you
mad
e at
th
e be
gin
nin
g of
th
is a
rtic
le.
Wh
at d
o yo
u n
eed
to
add?
Wh
at d
o
you
nee
d t
o ch
ange
?
Len
gth
of
Dayli
gh
t in
th
e N
ort
hern
Hem
isp
here
Lati
tud
eSu
mm
er
sols
tice
Win
ter
sols
tice
Eq
uin
oxes
0° N
12 h
r.12
hr.
12 h
r.
10°
N12
hr.
35 m
in.
11 h
r. 25
min
.12
hr.
20°
N13
hr.
12 m
in.
10 h
r. 48
min
.12
hr.
30°
N13
hr.
56 m
in.
10 h
r. 4
min
.12
hr.
40°
N14
hr.
52 m
in.
9 h
r. 8
min
.12
hr.
50°
N16
hr.
18 m
in.
7 h
r. 42
min
.12
hr.
60°
N18
hr.
27 m
in.
5 h
r. 33
min
.12
hr.
70°
N24
hr.
0 h
r.12
hr.
80°
N24
hr.
0 h
r.12
hr.
90°
N24
hr.
0 h
r.12
hr.
Inve
stig
atio
n 3
: Se
ason
s 1
3
Day a
nd
Nig
ht
We
take
day
an
d n
igh
t fo
r gr
ante
d. T
hey
alw
ays
hap
pen
. Ear
th r
otat
es o
n it
s ax
is, a
nd
the
Sun
ap
pea
rs t
o ri
se; t
hen
th
e Su
n a
pp
ears
to s
et. T
his
cyc
le h
as h
app
ened
at
leas
t as
lon
g as
hu
man
s h
ave
been
on
Ear
th. I
t w
ill
mos
t li
kely
con
tin
ue
for
mil
lion
s of
yea
rs.
Bec
ause
Ear
th i
s ti
lted
, th
e le
ngt
h o
f
day
an
d n
igh
t fo
r an
y on
e pl
ace
on E
arth
chan
ges
as t
he
year
pas
ses.
Th
is t
able
sh
ows
how
hou
rs o
f d
ayli
ght
chan
ge a
t d
iffe
ren
t
lati
tude
s du
rin
g th
e ye
ar. W
hen
it’s
su
mm
er
in t
he
Nor
ther
n H
emis
pher
e, t
he
Nor
th P
ole
tilt
s to
war
d t
he
Sun
. Du
rin
g th
is t
ime
at t
he
Nor
th P
ole,
th
e Su
n n
ever
set
s. A
bove
th
e
Arc
tic
Cir
cle
(66.
5° n
orth
), d
ayli
ght
can
last
up t
o 24
hou
rs o
f th
e d
ay i
n t
he
sum
mer
.
Dar
knes
s ca
n la
st u
p t
o 24
hou
rs o
f th
e d
ay
duri
ng
the
win
ter.
Thin
k Q
uest
ion
sG
o ba
ck t
o yo
ur
not
eboo
k en
try
abou
t
the
reas
ons
for
the
seas
ons
that
you
mad
e at
th
e be
gin
nin
g of
th
is a
rtic
le.
Wh
at d
o yo
u n
eed
to
add?
Wh
at d
o
you
nee
d t
o ch
ange
?
Len
gth
of
Dayli
gh
t in
th
e N
ort
hern
Hem
isp
here
Lati
tud
eSu
mm
er
sols
tice
Win
ter
sols
tice
Eq
uin
oxes
0° N
12 h
r.12
hr.
12 h
r.
10°
N12
hr.
35 m
in.
11 h
r. 25
min
.12
hr.
20°
N13
hr.
12 m
in.
10 h
r. 48
min
.12
hr.
30°
N13
hr.
56 m
in.
10 h
r. 4
min
.12
hr.
40°
N14
hr.
52 m
in.
9 h
r. 8
min
.12
hr.
50°
N16
hr.
18 m
in.
7 h
r. 42
min
.12
hr.
60°
N18
hr.
27 m
in.
5 h
r. 33
min
.12
hr.
70°
N24
hr.
0 h
r.12
hr.
80°
N24
hr.
0 h
r.12
hr.
90°
N24
hr.
0 h
r.12
hr.
Inve
stig
atio
n 3
: Se
ason
s 1
3