Astronomy & Space. How Is Possible For Astronomers To Know The Shape Of Our Galaxy?

Astronomy Space : How Is Possible For Astronomers To Know The Shape Of Our Galaxy

Are the pictures of the Milky Way galaxy just best guesses or did they use some other method? ~~~ Kelly Gazo ~~~

Best Answer To Astronomy Space Question

It is hard to see the shape directly, since we are inside the Milky Way galaxy. But by charting the "proper motions" of many stars, astronomers can tell the general pattern of the clouds of stars going around the core. Then observing a similar galaxy like M31 in Andromeda, they could tell that those stars were moving the same way. So for many years we thought it was a twin to our galaxy, or perhaps just a bit larger. Only recently was it determined that there is a short bar of stars in our core, rather than a sphere shape. So the Milky Way is a "barred spiral" rather than a regular one like Andromeda. The bar is pointed towards us, and difficult to determine its size. Also, infrared telescopes are now very good at penetrating the dust clouds nearer the center of the galaxy. These prevent us from seeing very far in that direction with normal telescopes in visible light.

All Answer To Astronomy Space Questions

Answer 1

Any photos you see of the Milky Way were taken from Earth or nearby satellites - we dont have any probes outside the galaxy to take a picture. We can make pretty detailed drawings though based on our measured distances to stars. You can build up a 3-d model pretty easily just knowing how far away things are.

Answer 2

The pictures from outside are either pictures of *other* galaxies or artistic representations of what we think it night look like. Pictures from inside, like the sources, are actual photographs. You can just see it like that with your eyes in you get out of the city with all the street lights. Many national parks have very dark skies and you can see the Milky Way easily there. Summer is the best season to see it, because the part toward the center is up at night then.

Answer 3

The pictures that show us from above/below are certainly not real - they are photos of other galaxies which we just show to get a general idea. As for the shape - we look at what we can see, we analyse how far it is (possible with modern equipment), and then we build a picture. It has to do with the fact that our 3D world can be drawn not only with length, width, height, but also with two angles and a distance. Astronomers calculate this, and then see if they can make a model. It\s just like you could look at cubes floating in the air, and, if they aren\t in each others way, you can picture how they would look if you looked from the other side. However, scientists have it even easier - the distances can be calculated, and a star looks more or less the same from all sides. Thus, you get a decently accurate image.

Answer 4

It is hard to see the shape directly, since we are inside the Milky Way galaxy. But by charting the "proper motions" of many stars, astronomers can tell the general pattern of the clouds of stars going around the core. Then observing a similar galaxy like M31 in Andromeda, they could tell that those stars were moving the same way. So for many years we thought it was a twin to our galaxy, or perhaps just a bit larger. Only recently was it determined that there is a short bar of stars in our core, rather than a sphere shape. So the Milky Way is a "barred spiral" rather than a regular one like Andromeda. The bar is pointed towards us, and difficult to determine its size. Also, infrared telescopes are now very good at penetrating the dust clouds nearer the center of the galaxy. These prevent us from seeing very far in that direction with normal telescopes in visible light.