What happens when dark matter crashes into itself? Some new Hubble observations show that it's not what researchers thought — and that may have some implications for telling us just what dark matter really is.
Using shots from the Hubble Space Telescope and from the Chandra X-ray observatory, NASA scientists studied dozens of collisions of dark matter, like the ones you see pictured above — and noticed something unusual. After the crashes, the dark matter continued onwards, moving just as fast as before, in a trajectory that NASA compared to the motions of galaxies:
The team found that, like the galaxies, the dark matter continued straight through the violent collisions without slowing down much. This means dark matter does not interact with visible particles and flies by other dark matter with much less interaction than previously thought. Had the dark matter dragged against other dark matter, the distribution of galaxies would have shifted.
The results of the study were published today in Science.
Image: NASA and ESA.