To begin with, they orbited close to the plane of the ecliptic in the same direction as the planets, but their orbits were
deformed by the galaxy's tidal force and by interactions with nearby stars, gradually becoming more inclined and forming a more or less spherical reservoir,» Morais said.
As a result, light coming from a distant
galaxy will be deflected
by otherwise invisible globs of dark matter, causing it to appear stretched and
deformed.