TEACHER
RESOURCE
PLANETARIUM
STARDOME OBSERVATORY & TIES ON...
H
T
R
O
N
FINDING AY TIME
IN THE D
TIVI
FACTS, RESOURCES AND AC
where you
lost) you need to know
To find your way (not be
where we
us
w
sho
ps
Ma
.
get
to
are and where you need
st tell us
rth, South, East and We
are, and the directions No
nts, and maps
poi
al
din
car
the
ed
call
where to go. These are
day time,
h north at the top. In the
usually are oriented wit
your direction.
find
to
d
use
be
can
the position of the Sun
ctly
solar noon, which is exa
The Sun is due north at
en day. The Sun’s
giv
any
on
set
sun
and
between sunrise
nt south at solar noon.
shadow will therefore, poi
of the Sun’ resource and
See our ‘Rising and Setting
of where the Sun rises and
le
cyc
activity discovering the
sets during the year.
y’,
e as plain ‘noon’ or ‘midda
Solar noon is not the sam
watch.
or
ck
clo
r
you
to
ing
which is 12 o’clock accord
based
called ‘Civil Time’ and is
The time we use daily is
on ‘mean solar time’.
ies by about 15 minutes
The length of the day var
ause
ing the year. This is bec
dur
n
before and after noo
l
tica
ellip
its
ing
dur
n
s dow
Earth speeds up and slow
kland is at
Auc
in
n
noo
r
sola
–
orbit around the Sun
May, 12:27 in July and 1:05
1:35 in February, 12:17 in
er!
in October/Novemb
hour,
changing lengths of the
To avoid dealing with the
rs
hou
al
equ
24
rage’ day into
civil time divides an ‘ave
– a ‘mean solar day’.
de,
ations together by longitu
Civil time also groups loc
ctly
exa
is
t
tha
e
in a Time Zon
so in New Zealand we are
.
don
Lon
in
ich
12 hours ahead of Greenw
from
of New Zealand is 180°
t
par
no
e
aus
bec
However,
For instance,
ad.
ahe
rs
hou
12
ly
ual
London, no part is act
ill is
t of Greenwich (Invercarg
Auckland is just 174.7° eas
minutes of
20
ut
abo
has
d
klan
168.3°). This means Auc
‘daylight saving’ built in.
36
Auckland
38
New Plymouth
Wellington
Blenheim
42
Christchurch
44
Oamaru
Dunedin
46°S
Invercargill
Stewart Island
166
168
170
172
20 minutes
s in New
Sunrise and sunset time
n-rise-times/
astronomy/resources/su
http://stardome.org.nz/
S
T
N
I
O
P
N
O
I
S
S
DISCU
height of the Sun
AND DIR ING
G TIME
Y. SHAR
TELLIN
E
TH DA
NS
DURING
ERVATIO
S
B
ND O
D
N
A
IDEAS A
E
TIM
ABOUT
N.
THE SU
Gisborne
40
other resources..cal. Yearbook:
Check out these Zea
land – NZ Astronomi
E
SCIENC T/
N
E
CONT M LINK
ULU
R
ECTION
CU RIC
34
t
Spacecraf Sun
e
h
t
e
don’t us heir way
to find t e Solar
around th ecause
System b big
it’s too t!
and brigh
174
175
176
178
180°E
20 minutes
THE
EARTH
SPINS 5°
EVERY 20
MINUTES.
Why does the during the year?
at noon change
due east
s
e
s
ri
n
u
S
e
h
T
west only
and sets ydeuaer – when?
twice a
Which direction is
the Sun at noon
in the northern
hemisphere?
STARDOME.ORG.NZ
09 624 1246
ACTIVITY
PLANETARIUM
STARDOME OBSERVATORY &
H
T
R
O
N
G
N
FINDI HE SUN
USING T
ACTIVITY ONE
Task Two
Task One
AL SOLAR NOON
FIND THE TIME OF LOC
for your location on the
es of sunrise and sunset
Step 1. Look up the tim
newspapers, web sites
These are available from
day of your observation.
ical Yearbook.
om
ron
Ast
m) and the NZ
(e.g. www.timeanddate.co
imals) using
rs and minutes (not dec
Step 2. Calculate in hou
12-hour clock time:
e) + (sunset time)
(12 noon) – (sunrise tim
a) amount of sunlight =
+ (sunrise time)
(amount of sunlight) ÷ 2
b) time of solar noon =
W
USE THE SUN’S SHADO
TO FIND NORTH
e of local
Using the calculated tim
rk
solar noon in Task 1, ma
a vertical
the Sun’s shadow from
of
ner
cor
or
t
stick, goal pos
it will
und
gro
flat
On
g.
a buildin
rth is
point directly south. No
n.
in the opposite directio
Example:
rise 6:50am; sunset 5:50pm
Wellington 15th April: sun
of sunlight that day]
0 = 11:00 hours [length
a) 12 – 6:50 = 5:10 + 5:5
al noon]
0 = 12:20pm [time of loc
b) 11:00 ÷ 2 = 5:30 + 6:5
ACTIVITY TWO
USE AN ANALOGUE WATCH OR PORTABLE CLOCK TO
FIND NORTH USING THE SUN.
N
N
Step 1. Hold your watch (or portable clock) horizontally.
Step 2. Orient the watch so the 12 o’clock mark faces the
Sun. For greater accuracy, hold a toothpick, match or small
twig upright at the centre of the watch so its shadow lines
up with the 6 o’clock mark.
Step 3. An imaginary line from half way between the 12
o’clock mark and the hour hand will point north. Continuing
this line through the opposite side of the dial will point
south.
Step 4. If it is Daylight Saving Time, subtract an hour from
the position of the clock’s hour hand before finding the half
way point.
This can also be done with a digital watch by drawing a
representation of an analogue clock on paper and following
the steps as for an actual analogue timepiece.
T
he blue lines represent summer time
and the orange lines represent
Daylight Saving Time.
S
S
Take a photo of your activity and send it us.
We’d love to see it! [email protected]
org.nz
STARDOME.ORG.NZ
09 624 1246