Milky Way galaxy may be much bigger than we thought

[left-of-center2012]

New research suggests our galactic home spans a distance of 200,000 light-years.
by David Freeman / May.25.2018

The research, described May 7 in the journal "Astronomy & Astrophysics," indicates that our spiral galaxy's vast rotating disk of stars spans at least 170,000 light-years, and possibly up to 200,000 light-years.

It's hard to fathom just how far that is. If you could ride (at the speed of light) from one side of the disk to the other, it would take 200,000 years to span the distance. If you could drive across and averaged 60 miles an hour, it would take more than 2 trillion years. That's about 150 times greater than the age of the universe, which is estimated to be about 13.8 billion years.

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The research also gives a new sense of the sun's position within the Milky Way. Previously, it was thought that the sun orbits the center of our galaxy at about half the galactic radius. But now we know that some stars are more than three times that distance from the galaxy's center possibly more than four times that distance — so while the sun hasn't made any surprising moves, it's much closer to the center of the galaxy than we thought.

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One thing that hasn't changed is the number of stars in the Milky Way ... Astronomers believe the Milky Way contains about 200 billion stars.

https://www.nbcnews.com/mach/science/milky-way-galaxy-may-be-much-bigger-we-thought-ncna876966

[CloudWatcher]

1. bigger but not more massive

"Although we have increased the size of the galactic stellar disk, the number of stars and the total mass of the galaxy [are] not significantly affected because the outermost disk...has a very low density of stars,"

Bummer, I was really hoping that a systemic error in understanding galaxy sizes and masses could explain away the need for dark-matter, but no such luck!

[defacto7]

2. If we went 60 miles an hour

after a couple million years the Milky Way would not even be there anymore relative to some static point in space. If we were traveling relative to the same point in the galaxy, the galaxy would have changed size and shape and it wouldn't be relevant anymore.

But what if we went 70 miles an hour?

[yonder]

3. "But what if we went 70 miles an hour?"

it sounds risky, dangerous even. What, you a rebel or something?

[OxQQme]

4. What to Do When You Get Pulled Over for Speeding