ET Inspections—Part 2

...Continuing a fanciful visit to Earth from outer-space visitors looking for signs of intelligence here...

Visit 4, 700 million years ago. Volcanoes had burst through Snowball Earth's ice crust, spewing carbon dioxide into the atmosphere, causing the planet to warm once again. (In a similar fashion, we humans are now spewing carbon dioxide into the air, causing another global warming event.) At that time, our space visitors would have encountered microbial life forms that were very primitive. Nothing larger than a few microns, and certainly not intelligent. Nothing much of interest going on here at that time.

Visit 5, 400 million years ago. This would have been tens of millions of years after what scientists call the Cambrian Explosion, when millions of multi-cell critters had evolved. Many primitive animals and plants were flourishing across Earth. They were fantastically varied and our visitors would have been amazed at it all, but still have noted no intelligent life forms. None of those creatures appeared to be likely to build a space ship, let alone a stone hammer.

Visit 6, 100 million years ago. Outer-space callers would have found a tropical planet, with huge, reptile-like creatures crawling on land and swimming in its oceans. Countless kinds of plants would be thriving everywhere. Earth was bursting with life, yet no sign of technology could be found. Even though those giant lizards ruled the planet, our guests would conclude that intelligent life (at least smart enough to make rockets) was not there, and maybe never would be. All signs pointed to the fact that Earth life had settled into a stable, unchanging mode. Little did the visitors know that, had they come calling 35 million years later, life on the planet would be struggling to survive, in the aftermath of an asteroid crash that wiped out some 80% of all species.

Visit 7, six million years ago. At this time our extraterrestrial callers would find that Earth was populated by mammals—especially an intriguing one that walked on two legs. They would note the planet was changing rapidly, oscillating from hot periods to times when glaciers covered nearly half of the globe. Although the upright hominids appeared to possess the potential for intelligence, their technology consisted only of crude chunks of stone. Would they advance? Time would tell.

Visit 8, today. Our space travelers would discover a planet seething in hominids, who occupy every corner of the globe. They'd note abundant examples of technology that have rendered the lives of the hominids convenient and comfortable. Their structures are everywhere, as proof of their capabilities. They even have made the first tentative steps to leave the planet and investigate nearby worlds.

Yet something appears to be awry. Many of the planet's life forms are no longer healthy and thriving, but are threatened by the overzealous activities of the over-populous hominids. There is evidence that, in their push to extend their technologies, they have foolishly polluted their world. Yes, our visitors would discover a relatively advanced species, but would doubt that it has sufficient intelligence to survive much longer. The ET travelers conclude that these hominids are yet too savage... they fight incessantly among themselves and are trashing their lovely planet. 

Maybe if they returned in a couple of hundred years, they would find that these dominant hominids either smartened up and got their act together, or made themselves extinct. Whatever fate might await this “intelligent” species, the visitors have faith that the planet has previously survived worse catastrophes, after which life took a new tack and once again flourished.