![](http://68.media.tumblr.com/6caf3a2f199ffece288ad564bfc16d6c/tumblr_inline_ojld7aP2Ff1rfds44_540.jpg)
The earth has many infectious diseases (like Capitalism, White Domination, Ecocide, etc) that would spread to other planets and star systems if we did manage to colonize other worlds.
So I think we need to learn to live on and preserve earth and its ecosystems before we invest resources into colonizing other planets and systems.