What is the true mass of the Milky Way? New research has helped astronomers arrive at their most accurate estimate yet.
According to a team of researchers at McMaster University and Queen’s University, both in Canada, the Milky Way weighs between 400 to 580 billion solar masses. The sun’s mass is 330,000 times the mass of Earth, or 2 nonillion — a 2 followed by 30 zeroes — kilograms. In pounds, the sun’s mass is 4.18 nonillion.
When weighing the Milky Way, there are the masses of hundreds of billions of stars, planets, moons, gas and dust. Estimating the collective weight of visible material is the easy part, however. The difficult part comes when estimating the mass of dark matter — the stuff astronomers can’t see, yet to be directly detected in a lab or in space.