>>49
>>50
How about this...
We might end up stuck on this planet for eternity because chemical rockets are the only practical way to get into space and once fossil fuels get scarce human civilisation may not have the stability or foresight to mine the moon etc..
In the next 800 million years the sun will begin to burn more and more fuel as it begins to die and the earth's surface will be too hot for life to survive. Whatever happened in that 800 million years, whatever humans evolved into and what civilisations and 800*1000*1000 years of history they had will be wiped off for eternity and if in the rest of the unimaginably huge universe an alien species is more succesful than us and slowly crawls across it to find our solar system they will never know that sentient life once lived here. Our legacy would be a what if.
Sure we're selfish, I'm selfish, I want to be rich, but the fact that quadrillions of lives may or may not exist due to our actions here today certainly gives a new perspective to those parts of my psyche which encourage me to be selfless (or whatever part of my psyche gives me emotional pleasure for being selfless).