Haha...We've only 5 billion years left, Earth's on the end of
the journey...then BOOM the Sun goes supernova, consuming Earth,
and the planets of Inner Sol, thats why we have to dominate other
planets. Because if we are still on Earth in 5 billion AD, we're
definitely doomed. But, by 5 billion AD, if we are still alive, and
if we had started colonization by 2050 AD or earlier, then we would
have occupied a space of 16,000 light years in the Milky Way
Galaxy...