You can’t see dark matter. The reason why you can see normal matter is because light shines on it and reflects off it. That’s how you can see me. Dark matter doesn’t work that way. The light goes right through the dark matter. 

 

The way we detect/ dark matter is because it has / mass. Anything with mass affects other things via gravity, that’s the golden rule of mass. That’s what mass does. It tugs on / other things because of / gravity.

 

Without dark matter, the Milky Way couldn’t exist. So the galaxy is spinning, / the galaxy is spinning fairly rapidly. The reason why it can spin so rapidly is because it has so much dark matter. The dark matter has a lot of mass, and therefore it has a lot of gravity, and that’s what keeps the stars within around. 

 

If we were to magically take all the dark matter away from our galaxy, it would fly apart. The stars would just keep going straight, and in/ very short amount of time the galaxy would just be gone. There will be just a mass of stuff flying in very its way. And that’s not just true of our galaxy, it’s true of every galaxy, and every cluster of galaxy in the universe. They are all held together by this invisible stuff that we call dark matter. So we need the dark matter. It is the glue that holds galaxies together. 

 

The discovery of/ dark matter has revolutionized / star picture of the Milky Way. The stars of the galaxy represent just a fraction of its mass. The rest is made up of an invisible halo of dark matter. It surrounds you, me, and every single star. The stars are just the central region. The halo is at least ten times bigger, and weighs much more than ten times more. Then all the stars, and gas and dust that we can see, it’s the whole structure that’s the real Milky Way galaxy.