The Milky Way is big. It’s just simply big. ‘How big?’ has been a topic of debate among astronomers.

The reason for the heavy debate up until now is due to the amount of things we have. Asteroids, planets, stars, black holes, dark matter. All so much to factor into a calculation such as this.

Previous estimations have left the Milky Way between 500 billion solar masses and 2-3 trillion solar masses. Safe to say it’s a pretty big difference. The reason for such a large disparity can be attributed to the different methods than astronomers interpret the data of the Gaia and Hubble space telescopes. The fact that the hypothetical of dark matter needs to be factored in may lead to skewed data.  The new research actually has dark matter having made up to 90% of our known galaxy(hypothetically) but it is unknown as to the exact amount due to the fact that we cannot measure it.

Why do astronomers actually want to know the mass of our galaxy? Well, to start off, they cannot measure the interactions between galaxies or how the internal structures of galaxies evolve and change over time.

By combining data from ESA’s Gaia and the Hubble space telescope, astronomers at the European Southern Observatory have observed that the mass of the Milky Way galaxy is at 1.5 trillion solar masses, extending about 129,000 light years from the center of the galaxy. This means that the precise estimate seems to fall in the middle of proposed amounts by previous astronomers. In comparison to recent researches, this amount is actually on the higher end of recent estimates.

As previously stated, a majority is made up by dark matter at about 84% of the galaxy. Following that is 200 billion-ish stars that account for 60 billion solar masses making up about 4% of the galaxy. The last 12% is made up of materials such as clouds of gas, planets, asteroids, comets, and things like humans. The black hole at the center of the galaxy is estimated to be about 4 million solar masses.

All this data comes out to the Milky Way galaxy being considered an intermediate-massed galaxy. When compared to other galaxies of the same brightness, the mass is considered to be about the same. The Milky Way galaxy is considered to be on the greater 50% of solar mass. Evaluations of the dark matter in the galaxy will continue as part of future researches.