The Hitchhiker's Guide To the Galaxy

The Hitchhiker's Guide to the Galaxy aired for the first time at 10:30pm on Wednesday, 8th March 1978 on the BBC as a radio comedy. The radio show's popularity spawned books, a televisions series, several stage plays, a computer game and feature films.

The novel adaptation of Adam's radio series is a misnamed “Trilogy” of six books, five written by Douglas Adams – that sold more than 15 millions copies in his lifetime - and a sixth by Eoin Colfer.

At the release of the fourth book the series was named "trilogy in four parts," and the US edition of the fifth book was originally released with the legend "The fifth book in the increasingly inaccurately named Hitchhiker's Trilogy" on the cover. Subsequent re-releases of the other novels bore the legend "The [first, second, third, fourth] book in the increasingly inaccurately named Hitchhiker's Trilogy". In addition, the blurb on the fifth book describes it as "the book that gives a whole new meaning to the word 'trilogy'"

Before his death from a heart attack on May 11, 2001, Adams was considering writing a sixth novel in the Hitchhiker's series. Eoin Colfer, an Irish writer of Children's Books, most famous for his Artemis Fowl series, wrote the sixth book in the Hitchhiker's series in 2008–09.

Books in the Series (Trilogy) are as follows:

The Hitchhiker's Guide to the Galaxy

The Restaurant at the End of the Universe

Life, the Universe and Everything

So Long, and Thanks for All the Fish

Mostly Harmless

And Another Thing...

Two omnibus editions were created by Douglas Adams to combine the Hitchhiker series novels and to "set the record straight". The stories came in so many different formats that Adams stated that every time he told it he would contradict himself. Therefore, he stated in the introduction of The More Than Complete Hitchhiker's Guide that "anything I put down wrong here is, as far as I'm concerned, wrong for good." The two omnibus editions were The More Than Complete Hitchhiker's Guide, Complete and Unabridged (published in 1987) and The Ultimate Hitchhiker's Guide, Complete and Unabridged (published in 1997).

Inspired in part by Ken Walsh's Hitch-hiker's Guide to Europe published in 1971, which stresses the importance of towels to the travelling hitch-hiker, an important article to the Hitchhiker's in Adam's galaxy as well.

When Elon Musk's Tesla Roadster was launched into space on the maiden flight of the Falcon Heavy rocket in February 2018, it had the words DON'T PANIC on the dashboard display and carried amongst other items a copy of the Hitchhiker's Guide to the Galaxy and a towel.

The Illustrated Hitchhiker's Guide to the Galaxy is a specially designed book made in 1994. It was first printed in the United Kingdom by Weidenfeld & Nicolson and in the United States by Harmony Books (who sold it for $42.00). It is an oversized book, and came in silver-foil "holographic" covers in both the UK and US markets. It features the first appearance of the 42 Puzzle, designed by Adams himself, a photograph of Adams and his literary agent Ed Victor as the two space cops, and many other designs by Kevin Davies, who has participated in many Hitchhiker's related projects since the stage productions in the late 1970s. Davies himself appears as Prosser. This edition is out of print – Adams bought up many remainder copies and sold them, autographed, on his website.