Maybe, but unlikely. Life as we know it depends on some rare chemistry.

Carbon is the only atom [I know of] that can form long chains of double bonds (even triple though they tend to be unstable enough to not matter). Nothing else allows the chemical complexity needed for self reproduction.

Water is a weird molecule. Many chemical reactions happen in water that would be uncontrolled or not happen at all without water. The polar properties, the fact that is expands when it freezes (that is frozen water floats on liquid), and acid/bases are all interesting properties that are very useful for life. I suppose that something else could fill this role, but since water is common in the universe I doubt it.

Yes life elsewhere is unknown and so we cannot say for sure it will not look like our, but chemistry is a known.

Can you suggest another one?

• Robots that perform all the functions humans do, including making copies of themselves and teaching each other.

• Hive-mind species where there are no individuals.

• Species without any gender or sexual reproduction, whose individuals are spontaneously "born" in specific locations and conditions on their planet.

• "Species" consisting of a single, massive/long-lived individual.

• Parasitic intelligences that "infect" various other, unrelated species and direct them towards the goals of the parasites.

• Lifeforms floating around in gas giants or even in nebulas.

• Life-bearing planets themselves being a lifeform; that "reproduces" when the civilizations it supported upon itself go on to terraform other planets to become like their home planet.

The question is, how would it form by itself?

The fundamental thing about life as we know it is not just that it's made of the few particular elements it uses. It's about those elements being a sweet spot for molecular nanomachinery. It's not clear that any other combination of elements might be able to form a stable replicator and bootstrap itself into large-scale complex system. In fact, it might be that life can only arise by itself using materials our life is made of, directly because of laws of physics in our universe.

Or put in another way - if abiogenesis of our life is improbable, a spontaneous creation of robots - large scale machines with digital brains - is orders of magnitude less likely still.

When dom96 said "there could be very many ways for life to exist" I understood that to mean there could be very many different "biological substrates" (for want of a better term), nothing to do with how the species organises itself socially. The challenge is to come up with a hypothesis for "life" that's not based on long carbon chains.

I agree that only our imagination is the limit when discussing potential life. If matter that is not completely frozen (ie atoms stop moving) will eventually organize into some self-replication, any energy source could be enough.

It could be on the surface on active star, neutron star (someone already tackled that in sci-fi), all kinds of dwarfs, nebulas, maybe even something living off dark energy? Or black hole.

Energy means movement, and if matter/energy will eventually arrange into something 'alive', it might be enough.