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.
There were 9 Apollo missions by NASA that travelled to the Moon between 1968 and 1972. The first landing was on July 20, 1969 and there were 5 more missions that explored the lunar surface. A total of 24 astronauts went to the Moon (3 of them twice) but only 12 actually walked on the lunar surface. There were 9 Apollo missions by NASA that travelled to the Moon between 1968 and 1972. The first landing was on July 20, 1969 and there were 5 more missions that explored the lunar surface.