Over the years, there have been many science-based hoaxes perpetuated on the public.

One of the more famous is The Great Moon Hoax from 1835 which consisted of six articles published in The Sun, a New York Newspaper claiming discovery of life on the moon.

The articles described animals on the Moon, including bison, unicorns and tail-less and winged humanoids ("Vespertilio-homo") who built temples. There were trees, oceans and beaches. These discoveries were supposedly made with "an immense telescope of an entirely new principle".

You can read more about this in Wikipedia:

https://en.wikipedia.org/wiki/Great_Moon_Hoax

Another of my favourites, and perhaps the most famous, is Piltdown Man. A skull supposedly discovered in 1912 of the Missing Link, the species which showed the apparent transition from ape to human. However, 40 years later it was discovered to be a fake, a mixture of human and orangutan bones.

On to Time Travel hoaxes. Most of these seem to consist of apparently modern objects being found in historical works. The Painting at the top of this page dates from 1860 and supposedly shows a woman on her mobile phone. However, most likely it was a small prayer book.

And now for today's challenge, what is your favourite Speculative Fiction Hoax?

Answers and descriptions in the Comments section please.