NASA has some experience in the arena of looking at space photos and takes a look at NGC 3432. Where the Hubble Telescope reveals the image of a spiral galaxy that’s identical to our Earth’s own Milky Way.
This not-too-distant celestial body (it’s only 42 million light-years away!) is a spiral galaxy much like Earth’s own Milky Way.
“Dark bands of cosmic dust, patches of varying brightness and pink regions of star formation help with making out the true shape of NGC 3432 but it’s still somewhat of a challenge,” NASA’s statement.
This photo got you wondering how we could possibly know that the Milky Way is a spiral galaxy but Cornell’s website from former student Sara Slater found an explanation, who studied physics at Harvard and now works as a researcher at M.I.T.’s Kavli Institute.
Slater points to three clues that out our home galaxy’s general shape. First, researchers are able to make out the galaxy’s rough shape in silhouette by looking to the galaxy’s center. Our view of it is similar to Hubble’s edge-on look at NGC 3432, with the Milky Way appearing as a long, thin strip with a bulge at the center.
“This is a bit of a tipoff,” Slater wrote. She also noted that the measured velocity of stars and gas in our galaxy suggests “an overall rotational motion that differs from random motions,”
And that’s “another characteristic of a spiral galaxy.” And finally, the observed gas and dust content of the Milky Way also falls in line with that of other spiral galaxies.
“So, overall, it’s a pretty convincing argument,” Slater concluded.