How will the world end? Here are the Answers
While it is likely to kill many (or all) inhabitants of Earth, a massive asteroid or comet impact would not have the energy to destroy world Earth. Nor will there be a powerful supernova explosion in a few light years.
However, orbital instabilities in the Solar System could eventually lead to a disastrous collision between Earth and one of the other terrestrial planets, Mercury, Venus or Mars. But the probability of that happening is only 1 percent in the next five billion years.
The most likely scenario for the complete destruction of the Earth? The ‘red giant’ is burying itself in the Sun as it turns into a star. As the Sun’s thermonuclear fuel, hydrogen, is depleted in its core, our star’s outer shell will begin to expand. At this stage of its evolution, the Sun will lose a significant amount of mass, meaning Earth’s orbit will also expand.
However, current theory suggests that the new orbit will not be large enough for Earth to escape interaction with the expanding Sun’s lower atmosphere. This means that Earth will likely be evaporated by the growing star.
But don’t worry, this scorching destruction of Earth is far away. After about 7.59 billion years by some calculations. Even if our planet somehow survived and the swollen red giant remained in orbit around the Sun. Earth’s natural orbital disruption, dead. It means that it will merge with the remnants of the Sun.
Ultimately, whatever it was: that fate would come true in about 100 billion billion years. Not bad considering the universe is currently only 13 billion years old.