Physicists speculate that decaying neutrons may be producing particles unknown to science that make up the elusive dark matter.
Signal hints at possible interactions between ordinary hydrogen and dark matter in the early universe, but some scientists remain skeptical.
About 100 years ago Henrietta Swan Leavitt helped prove the existence of other galaxies. She is still inspiring astronomers today (infographic).
New simulations suggests life could exist in universes very different from our own.