TELESCOPES may soon be able to “see” the Universe’s dark matter—all
that stuff in space that doesn’t emit any light.
Astronomers have succeeded in locating and weighing a galaxy cluster solely
by the effect its gravity has on light from more distant objects. Within a
decade, their work could lead to a 3D map of the Universe’s dark matter, which
outweighs visible stars and galaxies by at least a factor of 10.
The astronomers exploited the phenomenon of “gravitational lensing”, in which
light from very distant galaxies is distorted by the gravity of massive objects
situated in a direct…


