This is Scientific American 60-Second Science. I'm Joanna Thompson.

In 2018, a group of astronomers from Yale discovered something odd.

Two galaxies that had almost no dark matter.

The observation caused a commotion in scientific circles,

because it seemed to fly in the face of everything that astrophysicists thought they knew about galaxy formation.

But researchers may have just discovered the mechanism that makes these so-called dark matter deficient galaxies possible.

In astronomy, matter comes in two flavors.

Dark matter and barions.

Yes, barions is a fancy way of saying regular matter.

That's Betsy Adams, an astronomer at Astoron,

the Netherlands Institute for Radio Astronomy, who was not involved in the research.

Unlike barionic matter, dark matter isn't visible.

Because the point of dark matter is that we can't see it.

There's no radiation from it. We don't observe it with our telescopes.

What we observe is the barions, the regular stuff.

And so to infer the presence of dark matter is we look for it's effects gravitationally.

Dark matter acts like the unseen glue that holds galaxies together.

Around 85% of an average galaxy consists of dark matter.

And without it, astronomers think that most galaxies wouldn't have enough gravity to take shape.

Stumbling across a galaxy without dark matter is a little like finding a hurricane with no wind.

So where the heck did the Yale Astronomer's dark matterless galaxies come from?

That question caught the attention of Jorge Moreno

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