H. G. Wells, in his 1898 science fiction classic The War of the Worlds, popularized the idea of Martian visitation and invasion. Even before Wells, there was a sudden upsurge in reports in "Mystery airships" in the United States. For example, "The Washington Times" in 1897 speculated that the airships were "a reconnoitering party from Mars", and the "Saint Louis Post-Dispatch" wrote: "these may be visitors from Mars, fearful, at the last, of invading the planet they have been seeking." Later, there was a more international airship wave from 1909-1912. An example of an extraterrestrial explanation at the time was a 1909 letter to a New Zealand newspaper suggesting "atomic powered spaceships from Mars."