Which lines in this excerpt from War of the Worlds by H. G. Wells suggest a future in which humans will inhabit distant planets

If the Martians can reach Venus, there is no reason to suppose that the thing is impossible for men, and when the slow cooling of the sun makes this earth uninhabitable, as at last it must do, it may be that the thread of life that has begun here will have streamed out and caught our sister planet within its toils.