Wednesday, February 3, 2016
Alien Theory (part 3)
Another theory to explain the absence of alien contact so far is that, if they ever did exist, they are all now extinct. Considering the volatile process for a planet to become habitable, it is very unlikely that microbes and other forms of life could have existed long enough or be plentiful enough that they could help balance the process. Life on a planet actually regulates greenhouse gases such as water and carbon dioxide, but without it, surface temperatures would be too volatile to support life for very long because most early planetary environments are unstable. Sudden and erratic heating and cooling on young planets would make it difficult for early life to survive and flourish. This delicate window of time is just one of the many factors that makes life on another planet very, very unlikely, even if they have habitable environments.