In all the planets of our home galaxy, humankind happens to discover itself on a planet which is perfectly suitable for life. Earth isn't without its dangers however. Earth has seen five massive extinctions throughout its history, due to catastrophic disasters like huge asteroids and massive volcanic outbursts. Billionaire entrepreneur Elon Musk is very much concerned about the next mass destruction. He's so worried that he thinks we have to get off Earth and grow into a multi-planet species as soon as possible, according to an article posted by blogger Tim Urban called How (and Why) SpaceX WillColonize Mars. Musk's thought is quite straightforward. Perhaps by the time the next huge asteroid heads our way, we'll have the equipment to protect the planet or redirect the space rock. But if it's something a bit more disastrous, like a neighboring star exploding, we may all get vaporized.
That's precisely why Musk is so hell-bent on Mars — it might turn out to be humanity's backup drive.
Musk doesn't just want to send a minority of colonists to Mars, either; he'd like to send 1 million people to the red planet. If we want anything similar to the industry and stuff built here on Earth, and generous genetic variety, then we'll need no less than that many people to get things going perfectly. That's the just the only way we'll persist as a species on Mars, Musk apparently told Urban.
Later this year, via his rocket firm SpaceX, Musk plans to disclose a spacecraft designed to transport as many as 100 people at a time to the Mars.