NASA accurately calculates Milky Way's weight using Gaia, Hubble telescopes

FoxNews.com/Science ^ | Mar 8, 2019 | Ann W. Schmidt | Fox News

[ETL]

Scientists have finally been able to accurately calculate the weight of the Milky Way, overcoming the difficult hurdle of measuring dark matter, the European Space Agency (ESA) announced Thursday.

After years of struggling to estimate the size of our galaxy, astronomers with NASA and the ESA used data from the Hubble Space Telescope and the ESA’s Gaia mission to determine the Milky Way weighs about 1.5 trillion solar masses within a radius of 129,000 light years from the center.

Because dark matter makes up about 90 percent of the galaxy, estimates of the Milky Way’s weight have differed widely in the past.

Previous measurements ranged from 500 billion to 3 trillion times the mass of the Sun.

"We just can't detect dark matter directly," Laura Watkins, of the European Southern Observatory in Germany who led the team’s analysis, said in a statement.

"That's what leads to the present uncertainty in the Milky Way's mass – you can't measure accurately what you can't see."

Because dark matter is so difficult to calculate, Watkins and her team measured the velocities of dense star clusters, called globular clusters, that orbit the galaxy’s spiral disc.

They used data from Gaia, the ESA’s space observatory, to measure globular clusters as far as 65,000 light-years away from Earth and data from the Hubble Space Telescope — a project shared by NASA and the ESA — to measure globular clusters as far as 130,000 light-years away from Earth.

[ETL]

[Sequoyah101]

Who is going to prove them wrong?

[Jolla]

NASA accurately calculates

about 1.5 is accurate?

[Captain Compassion]

“accurately calculates”? How could this be known? I’m just sayin’

[moovova]

Really? What's so complicated about that? It tells you the weight right on the package...2.05oz (at least, that's the weight this week).

[Cowboy Bob]

If they can calculate weight, that means they should be able to calculate size. How far is it to the edge of the universe?

[moovova]

And, it's obvious NASA had their top scientist on it...

[jetson]

Does anything really have weight in space? Doesn’t weight have to have gravitational properties surrounding it.

[moovova]

Oh, and thanks for the new background for my desktop display...it's lovely.

[Leaning Right]

> Who is going to prove them wrong? <

My money is on this guy:

[C210N]

Yeah, but now we know there are 3,000,000 times the solar mass of the sun of dark matter, in with that 2.5 oz.

[Covenantor]

The solar mass (M☉) is a standard unit of mass in astronomy, equal to approximately 2×1030 power kg.

...and contrary to conditions on earth, astronomical photos have a slimming effect such that the Milky Way looks 10 pounds lighter that it is.

[Leaning Right]

> Does anything really have weight in space? Doesn’t weight have to have gravitational properties surrounding it. <

Good catch. And you’re right. The title should have been: NASA accurately calculates Milky Way’s mass.

An error like that kinda makes you wonder about the rest of the article.

[ETL]

Mass.

[cicero2k]

Dark matter is an assumption to explain galaxy shape using gravity only.

What about electromagnetically charged plasma? That force would produce observed shape and does not require imagined matter.

[IronJack]

Next, they turn their sights on Rosie O’Donnell and Michael Moore. But not at the same time ...

[ETL]

Deriving the Galactic Mass from the Rotation Curve

https://www.astronomynotes.com/ismnotes/s7.htm#A2.4

[ProtectOurFreedom]

1 solar mass = 1.989 × 10³⁰ kg

1 trillion = 1 x 10¹²

Mass of Milky Way: 1.989 x 10⁴² kg

That's a BIG number. I've got my own conservation of mass program underway where I'm trying to transfer a few kg from my own mass back to the Milky Way. The Milky Way is welcome to my extra kg.

[Verginius Rufus]

Supposedly the earth is weightless. But it is also said to weigh 6.585 sextillion tons (that's 10 to the 21st power). The sun has 333,000 times the mass of the earth. So if the Milky Way's mass is 1.5 trillion times the mass of the sun, the weight of the Milky Way should be something like 3.3 duodecillion tons (or 10 to the 39th power).

But my math could be wrong. To get the weight in pounds, multiply by 2,000.

[Paladin2]

How hard can it be to weigh MilkyWays? They only have one Star.