Differences between the northern and southern hemisphere for stars?

Just as half of the earth is in the Northern Hemisphere and half in the Southern (by definition -- that's what "hemisphere" means), so half of the sky you can see lies in the north and half in the south.

People in north temperate latitudes, like me in New York, can see stars like the Big Dipper every clear night of the year. The great northerly stars, like Vega, Capella and Arcturus, can be seen at some time any night of the year.

Those in south temperate latitudes, however, cannot see the Big Dipper at all. Likewise for Polaris, the "W" of Cassiopeia and other far northern stars. In Australia, South Africa and New Zealand, they can see Vega, Capella and Arcturus, but only for a short time during certain seasons of the year. Capella, for instance, only creeps above the horizon a little way on summer evenings in Australia.

Those in the southern hemisphere can see some famous stars that we up north cannot. The Southern Cross never sets from New Zealand and southern Australia. Likewise the great Southern Pointer stars Alpha Centauri and Agena, and Canopus, the second brightest star in the entire sky.

In New York, I cannot hope to see the Southern Cross or Alpha Centauri. If I'd like to see Canopus, I'd have to travel to a place like Texas, where the star appears low along the horizon for a few months in winter.

Those in the Southern Hemisphere can also see the Magellanic Clouds, the only two galaxies other than the Milky Way that, with the unaided eye, you can make out as actual starry patches rather than just fuzzy dots. Those of us in the north can do no better than the Andromeda Galaxy which, if you know where to look, seems no more than a single blurry star.