NASA’s just taken the best accidental smiley photo ever. It’s galaxy cluster SDSS J1038+4849, and it’s got one hell of a creepy grin.
The photo comes courtesy of NASA’s Hubble telescope. It’s made up of two galaxies — each of the eyes — and the arcs are caused by something called gravitational lensing:
Galaxy clusters are the most massive structures in the Universe and exert such a powerful gravitational pull that they warp the spacetime around them and act as cosmic lenses which can magnify, distort and bend the light behind them. This phenomenon, crucial to many of Hubble’s discoveries, can be explained byEinstein’s theory of general relativity.
In this special case of gravitational lensing, a ring — known as an Einstein Ring — is produced from this bending of light, a consequence of the exact and symmetrical alignment of the source, lens and observer and resulting in the ring-like structure we see here.