[nukeman]

It’s 70 years after the death of the author. So if Andy Weir died tomorrow, The Martian wouldn’t enter the public domain until 2093.

[IndySun]

"...70 years.."

That rule does not apply globally. Depends on where you live.

[techdragon]

It’s most places, due to the international pressure from multinational organisations like the WIPO (World Intellectual Property Organisation) and WTO (World Trade Organisation) … they have longstanding campaigns to harmonies members national legislations to facilitate easier international trade and respect of intellectual property rights between countries…

As a result most countries (but, yes, not all countries) have the Bern convention “life plus 70”