Earth has been targeted time and again in A Torrent of Faces (1967) by James Blish and Norman L. Knight, Lucifer's Hammer by Larry Niven and Jerry Pournelle (1977), and in films such as Deep Impact and Armageddon (1998).The terraforming of alien worlds into an Earth 2 paradise has been a sci-fi staple since the term was first coined in 1942 by Jack Williamson in his Seetee Ship stories.