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.
First, the space shuttle is not designed or is able to go to the moon. It travels around the earth at about 250 miles altitude at around 17,500 miles per hour (around the earth in about 1 1/2 hours). The Apollo that did send men to the moon traveled at a maximum of 25,000 miles per hour, but the speed depended on where it was on the way to the moon.