Scientists have found more evidence for liquid water on Mars

My understanding is that "temporary" in this case means, like, "one million years or more."

While I appreciate that that's a very short span of time by both geological and evolutionary standards, I don't think it's meaningfully "temporary" by human standards.

The Long Mars (by Pratchett/Baxter) explores some ideas like that on a trip through parallel universes, though it's 3 books into a series that doesn't lend itself to skipping around.

Taking this one step further, it is also possible that life has been exchanged between our two worlds. Large meteor collisions in the past have moved parts of Mars to Earth, and possibly also Earth to Mars. And some small life can exist clung to rocks in space (we know of such creatures here on Earth)! So perhaps, Mars was once wet and warm and full of life. Perhaps it suffered a large impact of some kind billions of years ago, and perhaps that impact flung Mars rocks with little tiny Martians on them towards Earth. In fact, this could have happened thousands of times.

It's possible, anyway. You know, while we're speculating.

It's a pitty we are not digging in the underground of the planet yet; imagine the amount of fossils and history one could find if the planet had been habitated before.

I don't understand why that would be horrifying?

Terra forming Mars has never been something which I imagined we would do. I always thought we'd be living in greenhouses and digging for minerals and fossils.

Because this is far from the first evidence. There is plenty of evidence for liquid water on Mars both past and present. In fairness, the article mentions this. In spite of the headline, it only claims the first direct evidence. Personally, I think even that is a bit of an overstatement. To me, this is simply one more bit of evidence that supports the current scientific consensus.

This would be the first time they state there's liquid water naturally under one of our machines. For a starter, this is a huge problem regarding environmental protection. Regardless of the other factors against letting something like Conan the Bacterium take residence a few cm under the surface, I suspect if this had been suspected earlier (or those that suspected it were taken seriously), we wouldn't have sent the same kind of probes to the same areas, possibly not even having a Mars ground exploration program at all until we understood better how to do it without polluting the planet with terrestrial life.