[jl6]

How do we measure the distance to those galaxies to be sure that it’s really a ring, rather than something that looks like a ring from our perspective? I know that supernovas provide one technique for distance measurement, but it feels unlikely that we’ve done that for every galaxy in this structure?

[drtgh]

All the illustrations we see about galaxies are post-processed interpretations, they are not exactly photos per se. In this case, I think astronomers may be using the data sent by the Voyagers[1] as a ground truth for trying to interpolate the scanned one from distant galaxies.

It is not my field, but perhaps another probe should have been launched on a different axis as you indirectly suggest, although it should have been done at the same time. I'd bet someone at NASA thought on it and the budget stopped it.

[1] https://www.newscientist.com/article/dn21233-voyager-space-p...

[isthatafact]

Other galaxies are too far away for us to have any way to view them from a significantly different angle -- the solar system is tiny compared to the size of galaxies and the distance between them.

How does the voyager article relate to this study? It looks like voyager just got far enough away from the sun to detect something in our galaxy that was hard to see from earth due to being drowned out by the sun, and the rest is hidden by a paywall.

[drtgh]

Apologies, I didn't thought in the scale.

Certainly it is zero related to this study. I read the article that I linked thinking the Voyagers reached a distance far enough to use it as a stereoscopy through two sources, Earth and Voyager, with the Voyager's collected data. And therefore I thought that's what astronomers in general was using as reference to analyze galaxies (in the last decade).

After read again such article I keep thinking about how did I reached this process. Apologies again to everyone.

PS: I didn't noticed it was behind a paywall, maybe by this Archive capture,

http://web.archive.org/web/20151203203335/https://www.newsci...

[isthatafact]

No need to apologize. You might have been thinking of parallax due to earth location changing as it orbits the sun, which causes very small shifts in the apparent angular positions of stars. Closer stars shift more, which allows it to be used as a distance measurement to stars, but the effect is too small to measure for far away galaxies.

https://en.wikipedia.org/wiki/Parallax_in_astronomy