Earth – made for people
by Raymond Strom
Earth is an amazing place! It is no accident, or the result of random processes as is suggested by those who believe in planetary evolution. We outlined the pursuit of exoplanets in the last article, and how astronomers who believe in planetary evolution are looking for the evidence of life on those exoplanets. Size and distance from their suns present huge obstacles for the sustaining of life on those bizarre bodies. But there is more.
One of the things that must be right is the atmospheric makeup of those exoplanets. Much has been discussed in the professional literature regarding what would be right. It seems that if biology is carbon-based, as it is on Earth, then the atmospheric makeup would need to be substantively similar to what we actually have on earth. But there also needs to be other indicators in these atmospheres.
Oxygen presents a rather interesting factor. When did oxygen become a significant factor in the Earth’s atmosphere? Some argue that oxygen was a late arrival, and thus life based on oxygen is a late arrival as well. This appears not to be the case. Early in Earth’s history, the rocks demonstrate that oxygen was significant in the atmosphere. Red beds in the rock reveal significant amounts of free oxygen as being present to oxidize a number of associated elements. It must be kept in mind as well that if there is insufficient oxygen, aerobic life cannot survive. If there is too much oxygen, then harm can actually occur to life as well. Increase the amount of oxygen a few percentage points, and wildfires fed by oxygen would consume most of our plant life. It makes for a ‘no game’ either way!
One other thing that astronomers have suggested might be an indication of life on exoplanets is methane. Methane is produced by abiogenic (non-life) sources as well as biogenic (life) sources. Biogenic sources include insects like termites (which produce massive tonnages of the greenhouse gas methane) ungulates and people (you got gas? It’s methane!). So just find methane, and you find life, or so these explorers say. Just that simple, or is it? Methane is found where it seems there is no life. Titan, a moon of Saturn, has lakes (some would say oceans) of cold, liquid methane. Does it indicate life? No! So, discovering methane on exoplanets is not an indication that life exists on those exoplanets.
It seems that Earth’s atmosphere appears to be ‘made’ for life, and more specifically, for man. Once more, “In the beginning, God created …”
Next time: Earth, Amazing Biology