Availability Is Not the Same as Existence
We often treat what is available to us as though it were the boundary of what exists. The aurora makes that mistake easy to see.
Auroral activity is strongly affected by geomagnetic conditions, and seeing it also depends on where the observer is, whether the sky is dark and clear, and how far the auroral oval has expanded from the magnetic poles. A person can stand under a clear night sky and see nothing. That does not establish that no aurora exists anywhere. It establishes something about the conditions of access from that place at that time.
The distinction travels well beyond astronomy. A piece of information may exist without being available to us. A possibility may be real without being visible from our present assumptions. Another person's experience may be genuine without being directly accessible from our point of view.
None of this means that every invisible claim is true. Lack of access is not evidence for existence either. It simply prevents one inference: I cannot see it, therefore it is not there. Availability and existence answer different questions. Good inquiry keeps them separate.