a. You observe Polaris at an altitude of 70° in the North, a quarter moon just rising, and your watc
a. You observe Polaris at an altitude of 70° in the North, a quarter moon just rising, and your watch says its 6
AM EST in NYC. What time is it locally? What’s your latitude and approximate longitude? How do you
know? Where are you? (Hint: what’s the longitude of NYC? How many degrees of longitude per timezone?
You can use an online Atlas to see where you are).
b. Suppose instead, from the position of the Southern Cross, you estimate that the South Celestial Pole is at an
altitude of 25° in the South. You see a full moon halfway between the zenith and the western horizon, and
your watch tells you its 7 PM EST in NYC. Where are you?
Solution Preview
- Time distance = 6hrs
Angle distance 3600= 24hrs
? = 6hrs
360*60/24= 900
Longitude position= 90+73.650= 163.650W
How do you know? The first quarter of the moon can only be seen from the Greenwich meridian in the west of the earth. So the approximate position is 163.650W
(192 words)