The Cleansing

Advanced aliens have arrived to destroy any life on Earth and all the traces of our existence. Their mission is to wipe out any life in our Universe.
While unsuspecting humankind is not aware of deadly menace, alien invaders analyze intelligence information and get ready to initiate the cleansing protocol. Suddenly some of the data gathered disturbs those powerful unimpassioned aliens.

“Commander, we’ve received data from our intelligence probes.”
“Put it on the main viewer and give your report, Analyst.”
“It’s a poorly developed, organic, technological civilization. Third level. Primitive weaponry, but in significant quantities. No orbital defenses. No immediate threats to us. Life is concentrated only on the third planet from the star. There are a few individuals orbiting the planet. I recommend a simple cleanup protocol.”
“Recommendation accepted, Analyst. Begin sample collection and scanning. Cleaner, prepare weapons systems for a complete cleanup.”
“Understood, Commander.”
“Navigator, begin preparations for our next destination. We’ll be done here quickly.”
“Will do, Commander.”
“Analyst, report when ready. The Cleaner will wipe out all traces of life in this system.”
“Aye, Commander. However the analyzer is giving me some strange results. I think you’ll want to see this. I’ll put it on the main viewer. It looks like things have gotten pretty serious on this planet. It has a rich history. Full of disasters, catastrophes.”
“It does look strange, yes. I agree with you, Analyst.”
“By the look of these records, this is hardly the first civilization on the planet. It looks like life here is often destroyed, only to be born again. So many cycles, too. It’s surprising. I don’t know of any other worlds where the dominant species has so often destroyed itself, somehow survived, flourished again, and then exterminated itself once more.”
“Yes, I see. Perhaps this is a particularly vicious race, one fixated on self-destruction. The imperfection of organic life forms.”
“I don’t know, Commander. Judging by these records, more often than not, they were the causes of the catastrophes that led to the fall of each wave of civilization. But there have been other causes, too. Asteroids from outer space, attacks from other races.”