At 4,130 miles (6,650 km) long, the Nile in Africa is the longest river in the world. Some people consider the Amazon in South America to be longer. This is because the many hundreds of channels ...

Earth, as seen by Cassini's radar. In order to understand what landforms on Titan could be seen by Cassini's radar, researchers looked at well-known Earth landforms through Cassini's perspective. The ...