O’ the irony!
Having already spread billions of dessicated viruses and bacteria on the surface of Mars and most other local bodies, over so many missions, we now announced that:
“We may need to put men on Mars before we can really rule out life on the Red Planet once and for all”.
So man arrives on the surface of a planet or moon not as a single human entity – but as a biosystem of billions of cells, the majority of which are not human BUT viruses and bacteria.
But we will have little idea which are ours and so came with us versus which were already on Mars or Europa. Quite a quandary.
In 2017, we have only identified 10,000 viruses against millions of virus types that might exist even on earth. Everywhere we apply the latest virus detection hardware and software we discover breakthrough virus types.
We need to accept that “Life IS a Cosmic Phenomenon”.
Once we accept microbes are everywhere, on every body in the solar system (and maybe galaxy) we can openly start looking for more intelligent beings. More intelligent than we humans that is.