Towel Day has been religiously observed every year since it was founded on May 25, 2001, just two weeks after Adams' untimely death at the age of 49.

Towel Day has been celebrated every year since May 25, 2001, two weeks after Adams sadly passed away of a heart attack at the age of 49 on May 11, 2001. Get the Space.com Newsletter.

A towel, it says, is about the most massively useful thing an interstellar hitchhiker can have. Partly it has great practical value - you can wrap it around ...