We can be sure because its impossible to get a photo of the entire milky way, but otherwise it seems accurate enough, pointing to an outer spur and having two satellite galaxies
It’s true we can infer a lot of what it looks like from what we can see and using data from other galaxies. However that does often change. I’m not even sure which is the more current version right now, but here’s another version with four more pronounced arms. The same original arms are there, but the others are more dust and different star makeup than the first and could be more pronounced than once thought. There are also several different structural wave patterns rippling through the galaxy as it rotates.
Even if it was the correct picture (and how can you be sure) the arrow is pointing to the wrong place.
We can be sure because its impossible to get a photo of the entire milky way, but otherwise it seems accurate enough, pointing to an outer spur and having two satellite galaxies
It’s true we can infer a lot of what it looks like from what we can see and using data from other galaxies. However that does often change. I’m not even sure which is the more current version right now, but here’s another version with four more pronounced arms. The same original arms are there, but the others are more dust and different star makeup than the first and could be more pronounced than once thought. There are also several different structural wave patterns rippling through the galaxy as it rotates.