When astronomers using NASA’s Hubble Space Telescope uncovered an oddball galaxy that looks like it doesn’t have much dark matter, some thought the finding was hard to believe and looked for a simpler explanation.
Dark matter, after all, is the invisible glue that makes up the bulk of the universe’s contents. All galaxies are dominated by it; in fact, galaxies are thought to form inside immense halos of dark matter.
So, finding a galaxy lacking the invisible stuff is an extraordinary claim that challenges conventional wisdom. It would have the potential to upset theories of galaxy formation and evolution.