Is it possible that the universe could be eternal??...

[Aegon]

I think the vacant universe could easily be eternal; the universe is mostly empty space after all. People think of space and they think it's a "thing". It's not. It's the lack of things.

The things IN space are a different matter, like planets and stars. They would theoretically need to come into being somehow, so I doubt that matter is eternal. However, space itself is probably eternal in my opinion, considering that space IS nothingness.

Time is part of space-time. Space-time is the gravitational field, which in turn is part of the universe.  So time and the universe are concurrent. If there was a moment with no prior moments, then the universe has experienced a finite duration in time and also has existed for all time.

Just FYI you are replying to a 12-year old post