Alien and Virus.

I was just thinking.
Bacteria and virus's are living organisms...

so isn't it possible that these so-called Extra Terrestrials, we see on earth, may be some sort of bacteria or virus thats been mutating on our planet for, a quadrupal 1000 years?

Well it has recently been tested that bacteria can survive an impact and temperatures not thought possible. So it would be possible for a bacteria to survive on a asteroid, for millions of years travelling thru space. If hitting a ideal planet that supports its kind of lfe, like Earth, it could spread worldwide, in theory.

Look at astro biology:
www.kent.ac.uk...

Rocks from space:
www1.tpgi.com.au...

Well, bacteria are "alive", but viruses seem to hover between alive and not alive. It also crossed my mind mind often that maybe viruses could be nanorobots sent into the universe to spread life.