[gdani]

If life could spring up here (as they claim) from existing material merely by chance, then why shouldn't we assume that other life could spring up in other environments based on different materials?

I don't think NASA or anyone else interested in astronomy doubts life can exist under extremely different conditions than we are accustomed to on Earth.

Finding life thriving around thermal vents, with no sunlight, deep in the ocean on Earth opened many eyes.

For all we know, there is an awful lot of non-carbon based life out there.

As I posted earlier, astronomy is still in its infancy. Much more so for astrobiology.

[Straight Vermonter]

Finding life thriving around thermal vents, with no sunlight, deep in the ocean on Earth opened many eyes.

Yes but extremophiles evolved from more conventional life forms not the other way around. It would be much more of a challenge for life to originate in such an environment than to adapt to it.