Mayans never said the world was going to end. Its a load of bull. They said it would be a rebirth, and modern today Mayans said the calendar never ends and Mayans just believe in cycles.
Sure, the planet might undergo some drastic changes due to the shit happening where we cant see, but we live through earth quakes...I think it sounds more plausible that we're close to our next evolutionary step or as my friend puts it, a revelation for man kind.
And if you look at rebirth in a negative way like life would start from the beginning, our cycle hasn't really had enough time yet. Dinosaurs were on the planet for millions of years and we haven't been here as long.
And as for aliens and such, maybe some will come and contact with us, teach us, or we'll shoot at them like dumb shits and they'll attack. I cant wait for that day so I can sit there and wait to see what happens and laugh at retards who've spent their whole life building a bunk house underground thinking "this little tin tube will save me from earth quakes, nuclear war, and aliens! I just never stopped to think about becoming trapped in here with no air...Hmmm I'm dumb." hahaha