While fringe believers in the Mayan calendar bunker down for the imagined apocalypse of 2012, modern scientific minds are looking to the distant future to find what might really destroy humankind, the earth, and everything else in the universe. Writing for the Independent, astronomer Chris Impey explains that small meteors smash into mankind’s home planet fairly frequently, but about every 100,000 years a massive projectile strikes, causing global tidal waves and creating a dust cloud capable of killing off all of the world’s vegetation. Every 100 million years an even more massive asteroid hits home, immediately killing all large land animals and soon after destroying everything in the sea as photosynthesis stops. Scientists carefully monitor the skies to make sure we know of these huge space projectiles while they’re still far off, giving us enough time to send up spaceships that could gently tug them off their collision course. But, scientists warn, while an asteroid could come along any day, and be prevented from hitting earth, there are much larger scale disasters looming that can’t be stopped. The sun will sputter out in 5 billion years, although by then the force of gravity itself could be turned into a source of energy that may keep mankind alive, and the Milky Way will fall apart as more of it’s stars turn to white dwarfs and black holes. Over trillions of years the same thing will happen across the universe, but its death could come even sooner. As cosmic expansion, spurred on by mysterious dark matter, continues to accelerate, plants, stars and galaxies will be torn apart and what scientists have coined “the big rip” will destroy the universe, and all energy and life within it. However, if researchers are wrong and that doesn’t happen, the universe could last for about 10^35 years, by which time protons will have become unstable, and existence itself will no longer exist.