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The universe that you and I see with our eyes, things that make up matter like galaxies, stars, planets, grass.

That's only 15% of the universe's total mass.

The rest is called dark matter.

This is mass in the universe that doesn't interact with light.

Astronomers know that dark matter is there, but they don't know what it's made out of.

So we don't know what dark matter is, but we know what it's not.

So when you think of a galaxy like our Milky Way,

it has three main components.

It has stars.

It has gas, but most of it is dark matter.

That's Jorge Moreno,

a computational astrophysicist, cosmologist,

and professor at Pomona College in California.

Like many scientists out there,

he would love to find out what exactly dark matter is.

And a new clue just dropped. It's called Cloud 9.

Cloud 9, I'd like to think of it as a bit of an underachiever.

He actually had all the resources in it to make a galaxy.

It had the fuel, it had all the conditions, but it just chose not to.

Cloud 9 is a failed galaxy.

It's a dark matter halo with a cloud of gas devoid of stars.

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