Jim Pilon, age 15, of Eugene, Oregon, for his question:

Can the Big Dipper be seen over China?

The dazzling bright stars of the Big Dipper can be seen anywhere north of the equator. It can be seen from anywhere in China because all of this expansive country lies in the Northern Hemisphere. However, its location depends upon where you are, just as it does in North America. The farther north we are, the higher the Big Dipper appears in the sky. Near the equator, it is so low that part of it dips periodically below the horizon.

The northern limits of China loop above Latitude 50 degrees North of the equator. Here the Big Dipper swings around a circle centered at a point 50 degrees above the northern horizon. This point is 40 degrees below the zenith, which is directly overhead. The southern tip of China is near Latitude 20 degrees North. Here the Big Dipper appears 30 degrees lower in the sky. At Peking, it occupies a place just below the halfway mark from the zenith to the horizon.