Following on from the conversation about Wonders of the Solar System...

The last episode was all about life on earth striving in the most unlikely and inhospitable conditions and comparing these conditions to those on other planets and moons.

A couple of things they mentioned were...

Varying clouds of methan in the atmosphere of Mars.
and
Subterranean liquid water on Europa and red markings on the ice on the surface of Europa.

What would happen if we got to these places and found that life did exist there and (especially in the case of Europa) it was potentially complex life?!

The world would go crazy! I can't imagine the effect that would have. Suddenly the race would be on to get back to these places and explore in more detail and more depth and possibly go out there with a view to coming back again!

Some lunatic will want to nuke it out of God’s Creation. Just you watch.

The race would consist of metanational commercial enterprise looking for profit, not to make a contribution, but a withdrawal.

I doubt that if life exists on Mars or Europa it has developed much beyond the bacterial stage. More complex life tends to require more energy to survive, so unless there was a thriving food chain in operation, it's most likely very basic.

The main problem with the whole issue of finding like is to make sure we don't take any there ourselves. I remember a programme on TV about the problems of building a device that could land on Europa, melt it's way through the ice (all 6km of it), then move about in the water while also being able to detect life, and it all had to be done autonomously and completely free of contamination. Tall order.