Here we see what appears to be a terrain editing interface, where mountain ranges are placed with a simple click.

A shot from a short animated sequence in the ViDoc that shows the sun traversing the sky over a mountain range. With few specifics, the sequence might indicate a vast, open world that, unlike the environments of Halo, might realistically depict the passage of time. Or it might mean nothing at all.

This presentation in Bungie's auditorium shows what might be an encounter design.

This particular starfield image seems to be associated with the new property, perhaps indicating they will stick with a science fiction theme, rather than something else, or a return to the more medieval fantasy worlds of Myth or the unpublished Phoenix.

This symbol also appears to be associated with the new project, and has been seen on some Bungie employee t-shirts.