科学家称,不要说是遇到外星人,就是在火箭上打个喷嚏也能成为长途太空飞行的最大风险。失重状态会使细菌在周围漂浮很长时间,这会增加宇航员的感染风险。人在地球上打喷嚏或者咳嗽时,细菌会在3到6步内落到地上,但是在失重环境下,它们会漂浮在周围很长时间,增加感染风险。能量限制导致飞船上无法广泛使用空气过滤 Not to mention the biggest risk of long-haul space flight, say scientists, are alien encounters, sneezing on rockets. Weightlessness can cause bacteria to float around for a long time, increasing the risk of astronaut infection. When people sneeze or cough on Earth, the bacteria fall to the ground in three to six steps, but they can float around for long periods of time in a weightless environment, increasing the risk of infection. Energy limitations lead to widespread use of air filtration on spacecraft