Presuming SpaceX pull off their plans, there will be trips to and from Mars. We'd better be pretty sure what microbes we're being exposed to or bringing back to Earth before we do.
Or we might get a repeat of when the Spanish brought disease to the Inca and Maya.
The mere knowledge of life is viable off-Earth is huge. If we find it on our nearest neighbour, the chances of encountering it elsewhere rise markedly. Hopefully it would trigger a search elsewhere in the solar system, like Europa.
>> Or we might get a repeat of when the Spanish brought disease to the Inca and Maya.
Unlikely. There's been no animal hosts on Mars, in which such a micro-organism might have evolved to threaten humans on Earth.
Not to say we shouldn't be careful for other reasons though. The bigger risk is the sudden extinction of entirely different branches of life, by more highly-evolved Earth-originating species.
I think the other person is saying that Earth bacteria could potentially wipe out Martian bacteria if the conditions are right. And that would be tragic.
That was exactly my thought. We discover extraterrestrial life, and inadvertently wipe it out, or just swamp them with an invasive species, without getting a chance to study them before we mucked up their ecosystem. As you say it would be tragic, but also very typically human.
Or we might get a repeat of when the Spanish brought disease to the Inca and Maya.
The mere knowledge of life is viable off-Earth is huge. If we find it on our nearest neighbour, the chances of encountering it elsewhere rise markedly. Hopefully it would trigger a search elsewhere in the solar system, like Europa.