The universe is stunningly vast. There may be other universes, equally vast. What are the implications for us humans?
One would think the contemplation of such vastness would tend to place a limit on our self-regard. It's difficult to assign oneself--or anyone else--a great deal of importance in the face of such immensity. In fact, it's difficult to consider humanity as a whole as having any significance. And, when one comes to that conclusion, it may be difficult to think of any human concerns as having any significance.
At that point, one might be tempted to descend into the kind of romantic despair which typified far too much of European literature in the 19th century and into the 20th century. Worse, one might begin to think like all too many European philosophers during the same period, perpetually encountering and bewailing abysses, horrors and fears of all sorts stemming from the admittedly repugnant (for some) realization that one's fate is not of essential importance to the universe. Worse yet, one might become a nihilist.
Replacing self-regard with self-pity is hardly useful, however, nor does it say much for one's fortitude. It should be possible for us to live contentedly even knowing that we are not the focus of creation. It may even lead us to live better. When we recognize that our concerns are not the essential bases of reality we may be less inclined to do things like fly airplanes into buildings, or otherwise seek to kill or control people we think are wrong, to satisfy ourselves or someone, or thing, or because we believe it to be for the good.
I sometimes wonder what the ancient stoics would have thought if they knew the universe to be as vast as we do. I think that their understanding of the tenants of stoicism would not be much altered, and that they would remain stoics. Some claim that stoicism encourages a kind of selfishness, but I think it is more the case that it induces detachment. The concerns of most, which appear small and insignificant given the immensity of reality, are not of much concern to the stoic in any case. The stoic knows that there is very little within his control, and doesn't seek to control anything but what he can control, which are things which cannot be influenced by any other person or source. The stoic does not believe himself to be of great importance, and sees himself merely as a part of nature, and therefore seeks to live "according to nature."
The ancient stoics believed that humans shared in the divine in that they can reason. In that sense, stoicism is somewhat anthropomorphic. But the stoic divinity has never been seen as human, or even human-like beyond being the fact that humans have the capacity to reason. As a result stoicism is not subject to the kinds of questions the vastness inevitably raises for those belief systems which focus on humanity, i.e. are premised on the assumption that humans and their affairs are of the greatest importance.
The vastness of the universe serves, I think, to encourage and supplement the stoic point of view. Nature is so overwhelmingly impressive; it just makes sense to live "according to" it. Would the vastness of the universe effect the stoic view that nature is good, and that what occurs, as according to nature, is good as well? I think not. We don't consider that which impresses us and creates in us a sense of awe to be "bad."