Southern hemisphere

Question

If you are stranded on an island and wonder where you are. After a quick look at the sky, you determine that you are in the Southern hemispher. How did you conclude this?

Answer

A quick look in the sky at night will show you a different sky. Take a familiar constellation like the Big Dipper and the stars pointing to the North Star for example. In some places you might be able to see some of the dipper, but not the North Star. There will also be two not too faint "clouds" of light in the sky, Magellanic Clouds. There is the Large one and the Small one about 20 degrees apart. You couldn't miss them, especially in the darkness of a deserted island. That would be you biggest clue even if you are not too familiar with the sky.

Incidentally you could tell during the day too, but not in an instant. Notice where the sun rises and where it is going to set. Here in the north it rises in the east and travels across the southern sky setting in the west. In the southern hemisphere, it rises in the east and travel an arc across the northern sky. It would give you the impression that the sun was rising in the west and setting in the east. The shadow of a sundial would also appear to be moving counter clock-wise.