Ogilvy is an astronomer the narrator knows well and recently they e discovered beams of smoke coming from mars. Apparently they are missiles by advanced human species which many astronomers refuse to believe such notion. The narrator takes a walk with his wife and they both see a tranquil scene in the sky.
Humans nowadays believe there are other life forms on this universe platform, and I can understand how anyone in the past would consider it to be far fetched.
I don't think they mean harm, it could be something not from mars. It could be humans from earth trying to wipe out the population to be in control. Mars could just be a false shield to make people believe it's martians.