Gravitational lensing. Hubble Space Telescope image of the Einstein cross" G2237 +0305, also known as Huchra's cross after its discoverer John Huchra. The photo shows five images; the central spot is a relatively nearby galaxy, while the four outer spots are images of a distant quasar. Light from the quasar has been bent by the gravitation field of the intervening galaxy, which acts as a giant lens, forming four images of the quasar. The quasar lies at a distance of around 8 billion light years, while the galaxy is 20 time closer at 400 million light years. Einstein proposed the effect of gravitational lensing in 1936."