Pioneering US astronomer  Vera Rubin dies at 88

Vera Rubin, a pioneering US astronomer who helped find powerful evidence of dark matter, has died. She was 88m, the Associated Press reports.

Allan Rubin says his mother died on Sunday night of natural causes.

Rubin found that galaxies don't quite rotate the way they were predicted, and that lent support to the theory that some other force was at work, namely dark matter.

Dark matter, which hasn't been directly observed, makes up 27 per cent of universe - as opposed to five per cent of the universe being normal matter. Scientists better understand what dark matter isn't rather than what it is.

Rubin's scientific achievements earned her numerous honors, including becoming the second female astronomer to be elected to the National Academy of Sciences.