NASA/ESA Hubble Space Telescope captured an image of two galaxies: NGC 4496A and NGC 4496B. The galaxies appear to reside beside each other in the constellation Virgo but have huge distances between them.
NGC 4496A is 47 million light-years from Earth, whereas NGC 4496B is 212 million light-years away. It means they are not interacting and only appear to overlap because of a chance alignment.
Chance galactic alignments offer astronomers an opportunity to examine the distribution of dust in these galaxies. By carefully measuring how dust in the foreground galaxy affects starlight from the background galaxy, astronomers can map the dust in the foreground galaxy’s spiral arms.
The resulting “dust maps” help astronomers calibrate everything from cosmological distances to the types of stars populating these galaxies.