Meanings of dark vastness in English

There were but a few women gathered in the gaunt, dark vastness of the nave.

Its dark vastness could only be guessed dimly, but rising from close below her feet was a great glow.

The stranger-Community focused its attention on Noah, electricity flaring and zigzagging, making a visible display within the dark vastness of its body.

Alan Saul, linked to his cerebral hardware, and what remained of his brain and organic augmentations, tried to comprehend the damage from a dark vastness.