I don't see the connection to killing the earth for our children. Moving the earth outwards is an effort to save the earth for our far future selves and our children.
I think "for our children" means "as far as our children are concerned" and failing to move the earth's orbit so it doesn't get eaten by the sun (despite being able to do it) would qualify as "killing the earth for our children". (The more usual referents being things like resource depletion and pollution with potentially disastrous long-term effects.)
This thread is for asking any questions that might seem obvious, tangential, silly or what-have-you. Don't be shy, everyone has holes in their knowledge, though the fewer and the smaller we can make them, the better.
Please be respectful of other people's admitting ignorance and don't mock them for it, as they're doing a noble thing.
To any future monthly posters of SQ threads, please remember to add the "stupid_questions" tag.