
Where Is the Sun Located in the Milky Way? - Santosh83
https://www.syfy.com/syfywire/where-is-the-sun-located-in-the-milky-way
======
rb808
Far out in the uncharted backwaters of the unfashionable end of the western
spiral arm of the Galaxy lies a small unregarded yellow sun. Orbiting this at
a distance of roughly ninety-two million miles is an utterly insignificant
little blue green planet whose ape-descended life forms are so amazingly
primitive that they still think digital watches are a pretty neat idea.

~~~
journalctl
Wouldn’t it be wondrous if the galaxy had plentiful intragalactic public
transit and we don’t have access because we’re the planetary equivalent of the
suburbs?

~~~
Vesuvium
You are not very far from what could be the reality. According to some
research the Solar System has 10% less hydrogen than other galaxies, so
Bussard ramjets will have an harder time

~~~
perl4ever
What if dark matter turns out the key to a decent space drive? There appear to
be galaxies without it (a good reason for believing it exists where there is
evidence) and so any aliens there would be SOL.

~~~
rolleiflex
Astonishingly enough, you might not be far off. That is the operating
principle behind the Alcubierre Drive.
[https://en.wikipedia.org/wiki/Alcubierre_drive](https://en.wikipedia.org/wiki/Alcubierre_drive)

Edit: Apologies, it seems it does not in fact use dark matter.

~~~
archgoon
Unfortunately, Alcubierre doesn't use dark matter. It uses negative mass (or
even imaginary mass) matter. Dark Matter is believed to have regular positive
mass (if it were negative mass, we'd be wondering why galaxies seemed to have
less matter than they should).

The existence of negative mass exotic matter remains an open question.

------
strictnein
Slightly offtopic, but what extraordinarily well done alt text for the major
images on this page. An example:

> "The most current map of the Milky Way is shown in an artist’s
> representation. The Sun is directly below the galactic center, near the
> Orion Spur. The Scutum-Centaurus arms sweeps out to the right and above,
> going behind the center to the far side."

They aren't quite following best practices with attribute usage, a
screenreader may read both the alt and the title text for example and they're
the same here, but to have the level of detail is really commendable.

~~~
gregknicholson
It's also a really good example of how captions (this is a caption really, not
exactly alt text) are context-dependent.

The caption you mention continues:

> The maser observed is almost directly opposite the Sun from the center in
> the S-C arm, 65,000 light years away.

...which makes no sense (there's no maser visible in the image or mentioned in
the article) until you realise that this image was uploaded for another
article and is being reused here.

Evidently the website's content management system asks for caption text when
uploading the image, rather than when selecting it for use in the article. The
latter is the right way to do it.

------
rb808
Its also a great time to replay the Contact Opening Scene
[https://www.youtube.com/watch?v=EWwhQB3TKXA](https://www.youtube.com/watch?v=EWwhQB3TKXA)
which has to be one of the greatest scenes in history.

~~~
basementcat
Related Abstruse Goose cartoon.

[https://abstrusegoose.com/163](https://abstrusegoose.com/163)

------
o09rdk
Off topic, but after my daughter was born I realized how sad and worried I was
that she wouldn't be familiar with looking up at the sky on a clear night and
seeing the Milky Way. Stuff like what's in this article is much more intuitive
if it's part of your schema of the night sky; it's more difficult to
appreciate when it's invisible.

She's too young to appreciate it now when I point it out to her when we have
the opportunity, and I worry that when she's old enough to appreciate it
she'll be someplace she can't see it. For me it was a common thing up until I
was a bit older, and now it's uncommon to be in the right place at the right
time to see it. I wonder if the unlit night sky will become something like
old-growth forests or other ecological sights that are long gone.

~~~
grecy
Go to the Southern Hemisphere, the stars are still epic there.

Story Time: I'm from Australia, but didn't got for almost 10 years. I lived in
the Yukon, roamed all of Alaska, etc. etc.

When I got to Australia after 10 years I walked outside in the middle of a
city of 50,000 people and almost fell over the stars were so bright and
colourful and (seemingly) close. They were so good, in fact, I took photos
right there in the middle of that city that are better star photos than
anything I have ever taken in Yukon/Alaska.

If you're still in doubt, go to Australia!

~~~
dharmon
The most incredible night sky I've seen is on the top of Mt John (there's a
small observatory) on the southern island of New Zealand. Mauna Kea wasn't
close.

You could see the band of the milky away across the sky. It was like something
from Hubble.

There's nothing like looking up in the sky and getting some perspective.

~~~
vkou
I could very clearly see the bands of the Milky Way from the summit of
Haleakala. My wife initially thought it was a cloud.

------
DennisP
When I was a kid, in the back of a sci-fi magazine I saw a t-shirt advertised,
with a picture of the galaxy. It had an arrow pointing towards the edge saying
"You are here." And another arrow pointing to the center, saying "All the
action is here."

------
mehrdadn
(Edited to correct/clarify)

Out of curiosity, what is the galactic centripetal acceleration for the Milky
Way that the Solar System is experiencing?

~~~
namirez
It's not easy to define a gravitational acceleration for the milky way since
for planets it's defined on the surface and the milky way has no clear
boundary per se.

That said, the escape velocity of our galaxy is 537 km/s; almost 50 times that
of the earth. Most of it is due to dark matter.

[https://www.newscientist.com/article/dn24249-stars-escape-
ve...](https://www.newscientist.com/article/dn24249-stars-escape-velocity-
shows-how-to-exit-the-milky-way/)

~~~
mehrdadn
Thanks! I worded the question poorly but this is also a cool number to know.

------
jedberg
I thought there was some recent paper that claimed our galaxy was not in fact
a spiral galaxy but more spherical than we thought?

~~~
enriquto
this is very surprising, considering that you can actually see it with your
own eyes at night and it is not spherical at all. There are also countless
panoramic photos of the whole thing, which always look more or less the same,
and there is no way it can be spherical. See for example
[https://www.eso.org/public/images/eso0932a/](https://www.eso.org/public/images/eso0932a/)

~~~
irrational
OP might be thinking of the recent finding that the galaxy is not flat.

[https://techcrunch.com/2019/08/01/the-galaxy-is-not-flat-
res...](https://techcrunch.com/2019/08/01/the-galaxy-is-not-flat-researchers-
show-in-new-3d-model-of-the-milky-way/)

~~~
ianburrell
Or maybe the older discovery that the Milky Way is a barred spiral galaxy. And
may not have a pronounced central bulge.

------
brownkonas
Is there any working directory of stars of the Milky Way with [x,y,z, t]
coordinates ? a galaxy class coordinate system ?

~~~
DennisP
I've seen databases of nearby stars, with just the 3D coords. Biggest I think
had 100,000 stars.

I don't think we have detailed data for the 100 million stars of the entire
Milky Way.

~~~
mr_toad
There’s at least 100 billion (not million). Maybe as many as 800 billion. We
can’t see most of them.

~~~
DennisP
Oops, of course you're right.

------
superfish
> But where is it vertically in the cake? Right in the center of that frosting
> layer, or off by a bit up or down?

Did the author answer these questions? How far above the center of the cake is
55 light years?

~~~
nobrains
He mentions that the height is 2,000 light years, so the deviation from the
center is 55 ÷ 1000 = 5.5% (+- 0.16%)

~~~
mirimir
I had no clue that the Sun's orbit looked like that. Bobbing up and down
relative to the galactic plane. More or less in a sine wave.

------
nerfhammer
so the Sun has both a vertical orbit as well as a horizontal one, with the
vertical orbit in 1/4 phase with the horizontal orbit. interesting.

~~~
Keysh
The period of the vertical orbit is closer to 1/3 that of the planar orbit:
roughly 70 million years, versus about 225 million years for the azimuthal
("horizontal") period. Since the periods aren't in an integer ratio (and you
wouldn't generally expect them to be for galactic orbits), it's also not
neatly closed like the schematic suggests.

------
cloudking
Is the galactic center moving and if so how?

~~~
bdamm
Relative to other galaxies? Yes, in fact I believe there’s a galaxy or two on
a collision course.

~~~
kuroikyu
AFAIK we (Milky way) are on a collision course with Andromeda.

------
british_india
Sol (our sun) is located between the Sagittarius and Perseus arms of the Milky
Way spiral galaxy. Specifically, our home is located on the Orion Arm.

~~~
selfsimilar
The article is about how much above or below the plane, specifically the
central plane of the galaxy we are. Spoiler: We're currently above (north) of
the central galactic plane by tens of light years, and still traveling
upwards, but it's cyclical and we'll be below the plane again in a few million
years.

