That wonder molecule of life on Earth, DNA, is being enlisted in the search for an exotic species dwelling in the cosmos: dark matter.

As far back as the 1930s, astronomers watching distant galaxies saw that something was missing. There were not enough stars to account for the strength of gravity needed to whirl galaxies so quickly or smash them together so swiftly.

Something else must surround and suffuse every galaxy, some kind of gravitational glue.