He did this by relating the light-year to the Astronomical Unit â the Earth-sun distance. One Astronomical Unit, or AU, equals about 93 million miles (150 million km). Another way of looking at it: the Astronomical Unit is a bit more than 8 light-minutes in distance. A light beam takes 8 minutes to travel the 93 million miles (150 million km) from the sun to the Earth.
Lake Superior sits between Ontario, Canada and New York. Lake Ontario is mainly fed by the waters of Lake Erie, which are transported via the Niagara River. Lake Ontario drains into the St. Lawrence River. Lake Michigan is the third largest of the Great Lakes and the only one entirely within the United States.
Great Lakes Flow. The animation illustrates how water flows from one Great Lake to another and eventually to the Atlantic Ocean. This profile view of the lakes demonstrates that water flows from Lake Superior to Lake Michigan and Huron. Lake Huron then empties into Lake Erie. At the end of Lake Erie the water level drops nearly 170 feet as it goes over Niagra Falls and into Lake Ontario. From here the water travels through a series of locks that bring it to sea level, out the St. Lawrence Seaway, and to the Atlantic Ocean.