Thanks so much for your blog which has led to learn more about biology.

I don’t think the issue of surface radiation matters. Humans will only live on Mars underground (or other shielded spaces). We may well live in lava tubes or spaces of our own creation. The microbes will happily live there and spread to similar environments.

This century is nicely shaping up to be the predicted century of biology. I look forward to it immensely. But that doesn’t mean we have to be careless.

What about “introduced” life? The thought has rarely stopped Earthlings before, when introducing life among different continents. Have you ever traveled between two continents? Every time you do that, you are carrying indigenous microbes to a new place where they’ve never been. Most likely pollen grains and insect eggs, too.