Dragonfly 44 - The Galaxy with 99.99 % Dark Matter (unknown type of matter) - Daily Dose of Science #3

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The new project - **DAILY DOSE OF SCIENCE **. It's about interesting discoveries or phenomena but put into a short body of text (only the direct explanations).

Main features:

• interesting, useful or intriguing facts
• extremely short explanations
• link to the original scientific page

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1. First of all:

We don't know anything about Dark Matter

Dark matter is an unidentified type of matter comprising approximately 27% of the mass and energy in the observable universe that is not accounted for by dark energy, ordinary matter, and neutrinos.

Why the "Dark Matter" name ?

Because it does not emit or interact with electromagnetic radiation, such as light, and is thus invisible to the entire electromagnetic spectrum.

We can't see it, we can't observe it regardless our methods. We just know it has to be there, but we don't know anything yet about it.

2. Second

We discovered a Galaxy with 99.99 % Dark Matter. Therefore we can see only 0.01 % of this galaxy.

In 2015, when the astronomers observed for the first time the Dragonfly 44 Galaxy they realized this one behaves very strangely: has a extremely small number of stars.

So, how was possible that so little stars can still form a galaxy ? What are the forces there ?

Recently, we found out the answer: in this galaxy there is a huge amount of dark matter that exerts gravitational pull between the stars. 99.99 % of dark matter.

99.99 % of "unknown" in an entire galaxy. That's AMAZING and UNIQUE.

Some facts:

1. The Dragonfly 44 Galaxy is 300 millions light years away.
2. It has a size like our Milky Way Galaxy: 70.000 light years. We have 100.000, but it's ok.
3. This galaxy should have been discovered long time ago. We have the Hubble Telescope. It can see billions of light years away galaxies. Why it didn't see this one ? We realized only now that this one exists because it's extremely dark. We see only 0.01 % of it. Maybe Dark Vader's Force is strong there.
4. How they discovered this amount of dark matter ? They saw the stars and observed their movement. They were moving very quickly, but their gravitational force wasn't enough. Therefore , in this case the unknown dark matter comes in place.

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This Weird Galaxy Is Actually 99.99 Percent Dark Matter
Dark matter
Massive new galaxy turns out to be 99.99 percent dark matter
image source