0821 GMT November 12, 2018
The standard model of cosmology, which assumes the presence and influence of dark matter, suggests smaller, satellite galaxies should orbit larger galaxies in a disorganized fashion, UPI reported.
However, surveys show the satellite galaxies orbiting the Milky Way and Andromeda galaxy exist on a single plane.
Until now, astronomers have largely dismissed the discrepancy, claiming the two galaxies are anomalies.
But now, scientists have shown Centaurus A's galactic satellites are also organized on a single plane.
The discovery — detailed this week in the journal Science — may force scientists to reconsider their models.
In their survey of Centauri galaxies, astronomers were able to use the Doppler effect to measure the movement of the distant satellites.
Their calculations showed 14 of the 16 satellite galaxies are found on the same plane.
The standard model of cosmology predicts only half a percent of all the galactic systems in the universe should feature such organization. But the latest discovery suggests such organization is more common.
Oliver Müller, an astronomer at the University of Basel, said in a news release, said, "Coherent movement seems to be a universal phenomenon that demands new explanations.”
Müller suggests astronomers must consider new ideas, like the possibility that satellite galaxies are debris leftover from large galactic collisions and that they are organized by tidal forces.