Alright, I take that 7.59 figure back. It's from a quick search engine search while I distracted myself from work with SN. But upon further looking at more sources online, they all seem to point to billions of years before Earth becomes engulfed by the Sun. We could be fucked much sooner though, probably several hundred million years from now from increased luminosity of the Sun, causing a rise in solar radiation. But only fucked if humanity is still around and still haven't been able to leave the Solar system.