article_snippet.sent: All the time when you walk outside, you are being pelted with organisms that come from space.'
article_snippet.sent: For example, life such as extremophiles, capable of surviving the inhospitable conditions of space, could become trapped in debris that is ejected into space after collisions between asteroids and planets that harbour life.
article_snippet.sent: These life-forms may travel dormant for an extended amount of time before colliding randomly with other planets.
article_snippet.sent: The idea that life can survive high the Earth's atmosphere, however, is not new.
article_snippet.sent: Scientists working with Nasa recently discovered bacteria living up to five miles above the Earth's surface.
article_snippet.sent: Air currents and winds are known to be capable of carrying dust and bacteria for hundreds of miles and high into the atmosphere.
article_snippet.sent: But research has shown that microorganisms can survive the intense heat and pressures of entering the Earth's atmosphere from space, raising the prospect that life may have originally been carried here.
article_snippet.sent: But already there is clear proof from many directions to confirm that we are constantly bombarded by fragments of comets that carry living microorganisms.'
article_snippet.sent: Perhaps there are luminous or 'invisible' jelly-fish like creatures that inhabit our skies, or microorganisms flooding our planet, I'm not convinced, but they are fascinating ideas that make a change from stories of starships loaded with aliens.'