We don't know for sure Mars is sterile. Seeding our own ecosystem is not worth losing the precious opportunity to see if there's life on Mars, and if it's anyt

We don't know for sure Mars is sterile. Seeding our own ecosystem is not worth losing the precious opportunity to see if there's life on Mars, and if it's anything like ours. That alone would advance science and philosophy significantly. Even finding fossils would be incredible. Also, if there's actually life in Mars, nothing guarantees our life will prevail over it. Maybe the nutrient-deprived native life will have a feast on ours, if our evolved defenses are innefective against their unknown threat.