Many teams have tried to estimate the mass of the Milky Way. An international team of astronomers has tried to combine the data of Gaia and Hubble space telescopes and estimated one of the most accurate masses of our galaxy. Our galaxy is packed with a lot of huge stuff like planets, stars, asteroids, etc. Calculating its mass is not easy and astronomers have not yet settled on a particular number yet.
Previously, the mass of our galaxy was estimated to be between 500 billion solar masses to 2-3 trillion solar masses (one solar mass is equal to the mass of Sun.) There is so much difference in the studies done by different astronomers and so the mass of Milky Way changes. The uncertainty of the masses is due to variable dark matter. It is an invisible form of matter and accounts for about 90 % of the galaxy’s total mass. Since it is not possible to measure this dark matter, astronomers cannot find the exact mass of Milky Way.
Accurate mass of the Milky Way is required to know how the internal structures of galaxies are formed, how our galaxy interacts with other galaxies and similar other cosmological questions. When they are not able to settle on the exact mass, all such queries cannot be solved.
Recently, an international team of European Southern Observatory in Garching, Germany, which is led by Laura Watkins, has put up a new approach for the mass of Milky Way. They have combined the data from two telescopes Gaia of European Space Agency and Hubble of NASA. Their analysis says that the total mass of the galaxy is 1.5 trillion solar masses approximately. The astronomers were surprised that their values fell in the middle of the previous estimates. The value now obtained is on the high end of the recent work.
In the universe, lower mass galaxies can weigh up to a billion solar masses and the highest mass galaxies can be up to 30 trillion solar masses. So, Milky Way is on the higher range of mass.