-According to records, dozens of planets like this one have been found,- Damien explained to the attendees.- There are approximately fifteen in this sector of the galaxy alone.
-And is there any explanation for the large number of inhabited planets in this specific region? -asked a young man of pale complexion and bristly black hair.
-There is no explanation for such a thing, it can only be a simple coincidence, we are a region with a large population of stars with good conditions to host inhabited planets - replied Damien -. There are those who have proposed the idea that there may have been some kind of propagation of amino acids and other complex organic molecules, but the mechanism by which this could have occurred is unknown, and the planets are very distant from each other.
-And how do you explain the fact that all life forms have suddenly become extinct, in such a short period of time, for no apparent reason? -asked the same young man.
-We also don't know exactly, but it is possible that it was some event of great magnitude, perhaps a gamma radiation bombardment, product of one or several supernovae, but it is only speculation, - replied Damien.
The ship of the Heracles academy, where the group of students and their professor were located, descended into the atmosphere of the planet, it was an Earth class planet, or Heracles class as it had been redefined recently, due to the current conditions of uninhabitability of the planet of origin of humanity. However, the planet was completely devoid of life forms, its atmosphere had invariable levels of gases, which coincided with those necessary for human life, as well as other species found on other planets.
-The fossil record of this planet shows that about two hundred and fifty million years ago, some sort of event occurred which completely annihilated, in a very short period of time, all life on this planet, -explained Damien, as the ship approached the surface of the sea, where a small pile of rocks rose from between the waters.
Slowly he landed on the surface and the class, which was on the observation deck, which was submerged beneath the waterline, could see that the rocks seemed to have been piled up on purpose, they were multiple cylindrical objects with rounded ends.
-Are these the remains of some kind of civilization, -asked in alarm, a beautiful young woman with a smiling face sitting in the front row of seats.
-No, look carefully, these are petrified eggs, a whole pile of them, -said Damien -. They are the eggs of a kind of aquatic creature, similar to a lizard. The event that caused the extinction of the creatures of this planet suddenly ended even with bacteria or any other organism that could have degraded the living matter, while the shell, although slightly porous, was formed by a mixture of minerals resistant to erosion and oxidation, over time the minerals in the water were absorbed by the eggs and petrified.
-Professor Damien, and was the spread equally abrupt and massive on the other planets of this sector? -asked the same young man with bristly hair as before.
-Yes, in general all the worlds suffered from a massive extension event situated in the same lapse of time, which ended up with absolutely all the life forms that existed in them, only an inhabited world, situated on the periphery of this sector managed to maintain enough life forms to be able to recover later," replied Damien - do you know what that world was?
The young people saw each other in silence.
-Thank you that I am not your astrometry teacher... look at this, -said Damien with a sardonic smile, after which a three-dimensional map of the sector of spherical space was projected into the space in the middle of the room, where the young people were arranged in three concentric circles in a row of seats, inside which was, almost in the center, the planetary system in which they were, while in a part of the surface of the sphere a point was illuminated, that later was extended to show a system formed by a yellow dwarf star, orbited by nine planets and another multitude of smaller objects-. Don't you recognize it?...it's the solar system, this is where we came from,- he said, and then he expanded the proximities of the star even further -. And that third planet is the Earth.