Based on gravity and the motion of objects, scientists calculate the massive weight of the Milky Way Galaxy.
The Milky Way forms a spiral shape with a mass hundreds of billions of times that of the Sun. Image: Fox News.
Calculating the mass of the Milky Way poses many challenges because it is our home, as reported by Live Science on December 12. Researchers typically “weigh” galaxies by tracking the movements of stars within them, determining how the galaxy’s gravity affects those stars. Humans can use telescopes to observe the entire Andromeda Galaxy but cannot see most of the Milky Way.
Stars near Earth and dust clouds obscure distant stars. Thus, researchers must employ more complex technical and statistical methods to deduce how the Milky Way moves and what it looks like when observed from the outside. Within the Milky Way, the Solar System’s orbit is not uniform, requiring researchers to adjust the data.
By studying the movement of gas, stars, and matter in various regions of the Milky Way, experts can calculate the actual mass of this galaxy. “The galactic disk is spinning but not uniformly. Objects at different distances from the galactic center move at different speeds,” explained Fabio Iocco, a co-author of the study and an astrophysicist at Imperial College London.
This rotation force must balance with the Milky Way’s gravitational force at each point on the galactic disk. Otherwise, the galaxy would tear apart, and stars and nebulae would be flung into the empty space between galaxies.
The Milky Way not only contains visible stars, gas, and objects but also dark matter. Although it cannot be directly observed, dark matter comprises a significant portion of the galaxy’s mass. This is consistent with most other galaxies. In this case, the mass of dark matter is equivalent to 830 billion times that of the Sun, roughly 93% of the Milky Way’s mass.
(From Live Science)