New Delhi, April 4 -- Before zombies shambled about, ghoulishly feasting on the flesh of those too slow to flee, aliens from outer space ruled movie theaters, drive-ins and late Saturday night creature features on television.

Even as Hollywood still drives how Americans envision little green men with big eyes and bigger heads, fiction soon could be separated from - or revealed as - fact if government agencies release secret files related to extraterrestrials and UFOs as called for in February by President Donald Trump.

The science fiction genre has shaped how people think about intelligent life elsewhere in the universe - "whether it's invasion narratives or aliens coming to warn us that we're on the wrong track or aliens just trying to...