Desktop Google searches could soon feel slightly out of touch compared to those done via smartphones as the company begins to push mobile search. Google has said it is fully splitting its search index into two versions: a rapid updated mobile one, and a secondary search index for the desktop web. SearchEngineLand reports: The news came today during a keynote address from Gary Illyes, a webmaster trends analyst with Google, at Pubcon. Illyes didn't give a timeline in his talk, but in a follow-up with Search Engine Land, he confirmed that it would happen within "months." Google first announced that it was experimenting with the idea of a mobile index last year at SMX East. Since that time, Google's clearly decided that a mobile index makes sense and is moving ahead with the idea. It's unclear exactly how the mobile index will work. For example, since the mobile index is the "primary" index, will it really not be used for any desktop queries? Will it only contain "mobile-friendly" content? How out-of-date will the desktop index be? Desktop usage is now a minority of Google queries but still generates substantial usage. The most substantial change will likely be that by having a mobile index, Google can run its ranking algorithm in a different fashion across "pure" mobile content rather than the current system that extracts data from desktop content to determine mobile rankings.