What If Earth got Kicked Out of the Solar System? Rogue Earth

The night sky seems peaceful and orderly. But in  reality, stars are careening through the galaxy at  

speeds of hundreds of thousands of kilometers  per hour. Not bound by static formations but  

changing neighborhoods constantly. Fortunately  space is big, and so the stars of the Milky Way  

are very unlikely to hit us. Unfortunately,  they don’t have to hit anything to make us  

have a really bad time on earth. And there  are already stars starting to get very close.

To understand how dangerous stars are  to us, we need to talk about gravity.  

Gravity attracts every piece of matter to  every other piece of matter in the universe.  

You are attracted by an atom a million  light years away and vice versa.  

Luckily, this force gets weaker over distance  and it also depends on how massive something is.

So things that are close and are very  massive are more attractive, winning  

the cosmic tug-of-war. This way, massive things  define how smaller things behave around them.

The sun makes up 99.75% of all the mass in the  solar system and so it shapes the behaviour and  

orbits of everything else in it. Billions of  years ago, after the sun was born the solar  

system was a chaotic and dangerous place  as the planets were formed from countless  

little pieces that collided constantly. But  over the eons, a stable balance emerged.  

Today most planets and asteroids have  settled into safe and predictable orbits.  

We have the inner and outer planets,  the asteroid and kuiper belt.  

And at the edge, the Oort cloud, a giant sphere  of comets orbiting slowly in cold storage.

We really don’t want this balance to be disturbed.