galactic mass

astronomy

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July 17, 2026

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The mass of a galaxy, such as our own Milky Way, is a complex subject in astronomy. Initially, scientists estimated the Milky Way's mass to be around 200 billion times that of the Sun, based on the rotation of hydrogen gas. However, later observations revealed that the gas's velocity didn't decrease at the outer edges as expected, suggesting the presence of undetected dark matter.12

Current estimates for the Milky Way's mass range from several hundred billion to possibly one trillion times the Sun's mass. The exact distribution and nature of this dark matter remain a significant puzzle in galactic astronomy, with theories suggesting it might be composed of undiscovered particles like WIMPs. Other galaxies also appear to contain this mysterious dark matter.13

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Milky Way Galaxy
Mass
The total mass of the Galaxy, which had seemed reasonably well established during the 1960s, has become a matter of considerable uncertainty. Measuring the mass out to the distance of the farthest large hydrogen clouds is a relatively straightforward procedure. The measurements required are the velocities and…
Read More
The total mass of the Galaxy, which had seemed reasonably well established during the 1960s, has become a matter of considerable uncertainty. Measuring the mass out to the distance of the farthest large hydrogen clouds is a relatively straightforward procedure. The measurements required are the velocities and…
Read More