izen, you probably have studied astronomy, but don't try to rationalize from your books, none knows......... we just depend on telescope, and connotative explanation from few glimpses of space-visited astronauts who were deceptive, telling to the taxpayer american , "we often can visit space" , it likes a pice of cake ( coz space flight was costly, but have brought worthless facts). Let's wait to Chinese, if their planning will bring some facts about living creatures weather exit or not besides earth.