We can detect the surface, so to speak, of our collective consciousness just as we can detect the visible surface of the sun (with dark sunglasses). For example, we say that the origins of our mythologies, religions, and cultures are contained in our collective consciousness. Everything about humanity is contained in it. The corona of our collective consciousness, so to speak, is that part of our collective consciousness that extends far beyond its surface, which means beyond what we can see in it (our mythologies, religions, and cultures) and is hugely more impactful. This is our love and our fear. They are huge parts of our collective consciousness, and they impact us greatly moment by moment. They are, metaphorically speaking, the corona of our collective consciousness.