Few things are more important than space exploration. And not just exciting but ultimately humdrum and sterile old robotic escapades. We have to send dirty old beings into the wide unknown and let them shed their organic detritus wherever they may go.
It's all about spreading life. We're at the brink of an evolutionary leap beyond the confines of our planet. And we should be exhilarated to be the force behind this evolution. One of the most jaw dropping words I heard as a kid was terraform. Wow! The power of such a concept was mind boggling back in the 70's.
So when I hear about the efforts to sterilize planetary probes, I'm deeply disappointed. Yeah, I understand. We're looking for certain confirmation that we're "not alone", that life is not a fluke but a universal principle. A dirty probe could taint our experiments. We could be jeopardizing the "planetary integrity of Mars".
The universe is not a curiosity for scientist to ponder from a far. Given the signs of life that we have so far observed on Mars, I'm not too concerned about maintaing the delicate balance of their ecological niche. With high likelyhood, there is no "they" to begin with. And if there is a they, they are probably no more complex than a Terran protozoa.
I'm as curious as the other guy whether life has independently evolved in other parts of our solar system. But I'm far more curious about the possibilities of establishing terran life on Mars. And the potential economic, social and evolutionary rewards should outstrip any white-coat impulse we have in this matter.
A first experiment could be in how we grow microbes and plants on other planets without our presence. The cost of sending primitive life forms to distant places like Mars would be minute compaired to sending human beings. It would probably only be slightly more expensive than current robotic missions since there would be little concern for the well-being of our microbial emissaires.