Could they make it on Mars?
Define “survive”.
They could remain their in an inactive form. They couldn’t actually live there, there’s no food.
They could eat dead tardigrades, at least for a while.
Could they wait for food sources implanted or lost in the biosphere by humans, once we get around to it?
They’ll eat the Mars lichens… and love it!
The existence of tardigrades doesn’t very well support the theory of saltation of the Earth by panspermia. That is, Earth didn’t get colonized by tardigrades.
We know this because we have good evidence for prokariotes (bacteria) that predate eukaryotes (cells with nucleii), and single-celled eukaryotes that predate multicellular life (all of which is eukaryotic).
Anyway, as mentioned above, what would they eat? No chloroplasts, so they couldn’t generate their own food from inorganics and sunlight. They need to eat other living (or dead) stuff.
Water would be an issue, but there might be subsoil water reservoirs of some kind. I remember they were looking for that a decade ago, but don’t remember the conclusion.
Problem solved!
A decade ago!? Have you been living under a rock? They have a robot up there looking for it right now, not to mention the previous two robots, one of which was still operating until quite recently. All of this has had plenty of media attention.
As I understand it, the current betting is that there almost certainly is water, but it has not yet been proved for certain.
And different robotsbesides the media whore robots. I knew I was onto something…