This galaxy, NGC 1052-DF2, is so diffuse we can see right through it to view more distant galaxies located behind it. The unusual galaxy is also missing most, if not all, of its dark matter.

Universe Calendar Observing Fascinating Cosmic Wonders
This galaxy, NGC 1052-DF2, is so diffuse we can see right through it to view more distant galaxies located behind it. The unusual galaxy is also missing most, if not all, of its dark matter.