Spaced out!

There are something like 60 stars within 16LY of earth, but we only know of 2 potentially habitable exoplanets within 25LY, though there may be others we cannot detect with present technology. Before we could even contemplate moving to another exoplanet we would have to:

1. Send unmanned craft to photograph potential targets, and then land on and analyse the atmosphere of any promising one(s), and look for any signs of life. Then, if we found a suitable destination,

2. We would have to send preferably several missions to learn all we could about both the target and the cleanliness of the intervening space and consequent risk of lethal collisions (and this could well vary with time).

3. We talk about Earth being the 'Goldilocks' planet, but when we say this we are looking through the wrong end of the telescope; Earth is not just right for us, we are just right for it, because we have evolved to live on it. And the conditions which (used to) suit us so well are the result of a complex balance between all the competing forms of life on Earth, including the vast flora inhabiting our guts, the guts of our food animals and the innumerable unidentified flora of the soil. Presumably these reactions have been moderated here because we all shared common ancestors, but even so there have frequently been major upheavals when we mixed up people from different countries/areas, as all the competing life forms from each side attempt to make use of the others.

If we travelled to an inhabited exoplanet the two groups would almost certainly be completely unrelated, and the interactions could be far more serious, regardless of the 'intelligence' of the inhabitants. I would consider it extremely unwise to visit an inhabited planet, so we would have to look for something like the proto-earth, which had a - to us - lethal atmosphere, and be prepared to survive on the supplies we brought with us while we searched for local sources of raw materials, and tried to build up a congenital atmosphere. All this would inevitably take many thousands of years, and even if we thought a planet was pristine we might well strike disaster if we had overlooked some nasty critters lurking in the dark corners because they were outside our experience.

 © Roger Riordan 2004-2019