A long term vision for humanity and its offspring must include the idea of stewardship, of gardening, nurturing and protecting the worlds we inhabit. When we travel, it will not be just ourselves we take with us, but our biosphere as well. It is therefore critical that we protect our biospheres...even more so to give us time to get off, and a place to come back to. In 2004, before becoming NASA administrator, Mike Griffin had some outstanding words on the subject, and what needs to be done:
"Mister Chairman and members of the subcommittee, thank you for giving me this opportunity to comment on the greatest natural threat to the long-term survivability of mankind, an asteroid impact with the Earth. "
To understand graphically just what a shooting gallery we really live in, check out the oustanding Java simulation below: