ASTRONOMY: Milky Way’s Faintest Companion Could Further Our Understanding Of Dark Matter.

A longstanding puzzle scientists seeking to study this exotic matter face is the missing satellites problem, which relates to how dark matter assembles itself into structures known as “dark halos.”

Our current theoretical models of galaxy formation suggest that a galaxy the size of Milky Way should be surrounded by hundreds of small dark matter halos, which, in turn, should lead to the formation of a comparable number of luminous satellite companions. However, so far, only 50 odd satellite galaxies to the Milky Way have been observed — a number that falls short of the theoretical prediction.

“This discovery implies hundreds of faint dwarf satellites waiting to be discovered in the halo of the Milky Way,” lead researcher Masashi Chiba from Tohoku University in Japan, said in a statement released Monday. “How many satellites are indeed there and what properties they have, will give us an important clue of understanding how the Milky Way formed and how dark matter contributed to it.”

It’s amazing — and frustrating — that 85% of the matter in the universe is invisible to even our most powerful telescopes.