If a fifth layer, why not a hollow Earth. Who knows what this planet could be hiding. Just think about it for a seck. Someone trust me on this

Well, with enough research AND D.N.A we could multiply the molecules and create a whole new/old species.

So if you think about it, we can actually do some Jurassic park stuff and recreate the species if we wanted too.

think of this, if they are sending dogs, why not send actual humanoid robots and access them with VR?