- New calculations show that the Milky Way is 890 times the mass of the Sun
- Experts say calculations account for factors that cloud mass measurements
- Elusive dark matter accounts for 93 percent of that mass, they say
Calculations clock the Milky Way at 890 billion times the mass of our own Sun with 93 percent of that coming from dark matter alone
Our galaxy has been put on a set of mathematical scales by scientists who have discovered the weight and bredth of the Milky Way. It is believed to measure 256,000 light years across
New and more precise measurements of our galaxy reveal just how massive it actually is.
In a paper published in pre-print journal ArXiv, several researchers from national laboratories, including the Imperial College of London, say the Milky Way Galaxy clocks in at a mass that is 890 billion times larger than our solar system’s sun.
As noted by Live Science, that equates to 6 billion billion billion elephants or about 296 quadrillion Earth masses.
While prior research has taken a stab at calculating the mass of the Milky Way, researchers say their own method has taken into account factors that can often cloud measurements and have, as a result, come closer to pinpointing the exact weight.
Galaxies are usually measured by calculating the movement of the stars inside. This gives them an idea of how its gravity is affecting those stars and therefore a sense of its mass.
In our own galaxy, however, that method is difficult to judge since our stars are obscured by surrounding gasses and other material. On top of that, our solar system constantly moves in its own way around our galaxy, adding another degree of difficulty in calculations of relative objects.
As a workaround, researchers say they developed sophisticated models that can judge how gas and stars move and gives them insight into what it looks like from the outside.
With those they were able to create a rotation curve – a plot of the orbital speed of stars.
As noted by Live Science, the orbital speed of those objects has to be equal to gravitational forces in the galaxy otherwise stars and other contents would be flung into intergalactic space.
In other words, discerning the orbital speed of stars and objects can be used to infer gravitational forces and eventually mass.
‘If you [calculate] for different distances, from the center until very far away, you get an estimate of the mass enclosed at increasing distances. So you can draw not only a total mass, but a mass distribution,’ co-author Fabio Iocco, an astrophysicist at Imperial College London told Live Science.
With their method, researchers say they were even able to calculate the mass of elusive dark matter – a mysterious and hypothetical substance that is theoriezed to permeate the Universe.
Dark matter accounts for a whopping 830 billion times the mass of our sun and makes up 93 percent of the galaxy, they say.