1 Drainage basin-the area of land drained by a river. 2  Catchment area-the area within the drainage basin. 3  Watershed-the edge of highland surrounding a drainage basin.4  It marks the boundary between two drainage basins. 5  Source-The beginning or start of a river. 6  Confluence-the point at which two rivers or streams join. Watershed-the edge of highland surrounding a drainage basin. 2  It marks the boundary between two drainage basins. 3  Source-The beginning or start of a river. 4  Confluence-the point at which two rivers or streams join.
Dangerous levels of radiation in space could bar astronauts from a mission to Mars and limit prolonged activity on the moon, experts now caution.However, more research could reveal ways to handle the risks that radiation poses to space missions.The magnetic field of Earth protects humanity from radiation in space that can damage or kill cells. Once beyond this shield, people become far more vulnerable.owever, more research could reveal ways to handle the risks that radiation poses to space missions. The magnetic field of Earth protects humanity from radiation in space that can damage or kill cells. Once beyond this shield, people become far more vulnerable.
On May 25, 1961, President John F. Kennedy announced before a special joint session of Congress the dramatic and ambitious goal of sending an American safely to the Moon before the end of the decade. A number of political factors affected Kennedy's decision and the timing of it. In general, Kennedy felt great pressure to have the United States catch up to and overtake the Soviet Union in the space race..