What if Mars was able to host life as we know it and its inhabitants polluted it to the point life could not exist there anymore?
The atmosphere of Mars indicates at first sight the presence of Carbon Dioxide and Methane. At this point this gases are product of the volcanic activity in Mars. Carbon Dioxide and Methane can also be related to the presence or not of life similar to what we know is life. A bizzare idea that comes to many minds is that Mars could be once a populated planet. And its inhabitants polluted it to the point that there was no way back. And that Mars is an example of what may happen to earth if we don´t make good use of our host planet.