Astronomers have created a vast cosmic map revealing an intricate web of dark matter and galaxies spanning a distance of one billion light-years.
This unprecedented task was achieved not by observing dark matter directly, but by observing its gravitational effects on ancient light traveling from galaxies that existed when the Universe was half the age it is now.
via Billion Light-Year Wide Web Of Dark Matter Mapped | Fox News.
Oh yeah? Well, if it’s dark then how’d they see it? Bazinga.