In the hunt for dark matter, are axions our best bet?

A composite image of the Bullet Cluster, a much-studied pair of galaxy clusters that have collided head on. One has passed through the other, like a bullet traveling through an apple, and is thought to show clear signs of dark matter (blue) separated from hot gases (pink). (Image credit: X-ray: NASA/ CXC/ CfA/ M.Markevitch, Optical and lensing map: NASA/STScI, Magellan/ U.Arizona/ D.Clowe, Lensing map: ESO/WFI)

Scientists investigating the true identity of dark matter are finding new evidence to support one leading candidate: axions.

Since its existence was first inferred in 1933, dark matter has remained an elusive “white whale” for scientists around the globe. While it is thought to comprise about 85% of all matter in the universe, what the invisible matter actually is remains a mystery.