About 65 million light-years from Earth, three galaxies don’t look quite right. They aren’t whirlpools bursting with light, but pallid objects dimly illuminated by a smattering of stars. “They have this ghostly appearance,” said Michael Keim, an astrophysicist at Yale University. And this isn’t even the weirdest thing about them. Dark matter is the invisible glue that keeps the largest…Source