Life - Elsewhere?
From time to time I hear fairly educated people talking about the importance of space travel and one part of there argument goes that right now we have all of our eggs in one basket - the Earth - and if there were to be a global catastrophe human life would disappear from the universe. They go on to say that with global warming that catastrophe may be coming and that we could be looking at "terraforming" Mars or Venus for mankind to call homes and thus avert this possible catastrophe.
Maybe I have just read too much, but I see some flaws in this. The first and biggest one is that the "terraforming" of Mars or Venus is a project many orders of magnitude greater than actually controlling any problems of global warming that we might have created unintentionally or that might be happening naturally and that with the Earth we are starting with something a lot closer to what we want to end up with than where we would be starting with Mars or Venus. That being said, it only speaks to the issue of space exploration in order to escape from the damages caused by global warming. Meaning that if we can terraform Mars or Venus - then surely we can cure the problems of global warming on the Earth.
Granted at some time in the future, we might want to spread our wings and spread humankind into space in the Earth-Moon system and beyond. Mars is a obvious candidate for we could with our current technology probably figure out ways to survive there. Venus might take a bit more for it would be like trying to set up camp in hell. I think the atmospheric pressures on Venus are like that of being deep undersea and the temperatures enough to melt lead in an atmosphere with enough of a sulphuric acid content to etch any metal you might have in your kitchen.
It would be simpler to create some sort of space colony than to live on Venus probably. Of course that is compared with converting the whole planet into another Earth. There is also a concept where you start by covering an area with a kilometre high dome and creating your biosphere under it and then gradually in a modular fashion expanding the area covered until potentially the whole planet is covered. That is called Paraterraforming or the "worldhouse" concept. Perhaps not with Venus, but perhaps Mars or even the Moon.
It does lead to questions like do we want to do something like convert Luna into another Earth? No longer would we have that creamy white or silvery white orb shining down on us, but would have a much brighter white and blue one potentially. We lose something to gain something. We do that every time a city expands.
Cities - which are most often built in a location where the farming was best - expand and most often cover up the adjacet farmland. You lose farmland when you gain residential and commercial land.
That is a lot like that expansion of mankind to a "New Earth" on the Moon. We lose the Moon and gain a New Earth.
The near future Moon missions planned by a number of countries of the world might lead to permanent colonies on the Moon which might in turn lead to thoughts on Paraterraforming the Moon. How much change to the appearance of the Moon are we going to be expected to accept? Should the general "man on the street"* have any say in it?
What of other places? How about "Earth Orbit"? The International Space Station is very visible from the surface of the Earth and in fact you can find charts and tables telling you when and where you might spot it flying overhead. I'm not sure but an observant person with a good set of eyes or binoculars might be able to even spot it during the daytime?
Will there be a time when the sky might be visually "crowded" where there will always be a number of objects flinging across the night sky - not unlike being near a major international airport at night? I rather enjoy watching planes go by, but there might be a time when there will be no place on Earth that one might escape that aspect of civilization without benefit of a cave or very steep mountain valley.
I don't know if we'll ever build cities in space - large rotating colonies where people can live in a shirt-sleeve environment essentially as if they were on the Earth. If they are in Earth-orbit they will be very visible. I wonder how safe we would ever be able to make them?
I wonder if we will have colonies on the Moon, Mars, and other Terrestrial and Ice Bodies of the Solar System? Will we have interstellar space colonies - which are travelling off to other stars where it will only be the decedents of the people who start off who reach them, and who essentially in the meantime are dwellers of the space between the stars?
I think that before we have the technology to terraform other planets, that same technology would allow us to save the Earth from any sort of runaway ecological disaster. But in the meantime I know we have to take care of our fragile planet. It is the only one we have.
* Yes I mean the gender neutral "man" and in "humans" or "mankind".