The Green Futures of Tycho is a 1981 science fiction novel for young audiences by William Sleator.

The book explores time travel and the consequences of Tycho's choices.

Tycho Tithonus finds a silver egg time machine that gives him the ability to travel into the past and the future.

[3] When Tycho visits the terrible future his actions will lead to, he risks his life to save his family by destroying the egg.

[3] The Green Futures of Tycho was one source of inspiration for the Interactive Fiction work Shrapnel by Adam Cadre.