> Launch a spacecraft to Mars full of organic material. Add the toughest possible bacteria (the kind that manages to survive in volcanoes for thousands of years

> Launch a spacecraft to Mars full of organic material. Add the toughest possible bacteria (the kind that manages to survive in volcanoes for thousands of years), vegetable growing experiments, etc... > Then see what sticks. Maybe it's nothing. But in the small chance something sticks, then humanity might have done the most useful thing ever, even in case humanity would go extinct: seed life on another planet. How would it be useful (in the sense I think you mean it to be)? Mars is pretty dead, and seems likely to stay that way forever (e.g. cold, dry). Any seeding, if successful, isn't going to result in some Star Trek-like scenario that results in intelligent life arising in a billion years. The only result will be bacteria eking out an existing in a marginal habitat for a billion years. > How long can we keep maintaining that? At some point we've gotta either send something that's good enough to inconclusively tell whether there already is life there (when are we expected to have the tech to achieve that?), or send something with life. The only upside I see to sending a spacecraft like you propose is to irreversibly contaminate Mars with life to eliminate the scientific basis for avoiding colonization and exploitation of it.