October 18, 1995: The Hubble telescope has discovered a new, distant class of quadruple or cross-shaped gravitational lenses. The new class of objects might eventually provide astronomers with a powerful "magnifying glass" for probing a variety of characteristics of the universe: the distribution of dark matter, the abundance of super-massive black holes, and the eventual fate of the universe.
In Hubble pictures of two such objects, astronomers have found four images of a faraway galaxy [the blue blobs] gathered around a red elliptical galaxy. A gravitational lens is produced by a massive object's enormous gravitational field, which bends light to magnify, brighten, and distort the image of a more distant object.See the rest:
Credit: Kavan Ratnatunga (Johns Hopkins University, Baltimore, MD)