This Hubble Space Telescope image shows the massive galaxy cluster eMACS J1823.1+7822, nine billion light-years away in the constellation Draco. The gravitational lensing caused by the mass of the cluster distorts background galaxies into streaks and arcs of light, giving insight into the distribution of dark matter.

A massive cluster of galaxies lurks at the center of this Hubble Space Telescope image. Like a sunken sea monster causing ripples on the surface, this cosmic giant creature can be described by the distortions of space-time around it. The mass of the cluster caused gravitational lensing of background galaxy images; The galaxy cluster caused enough curvature in space-time to distort the path of light and cause background galaxies to appear distorted as lines and arcs of light. Many other galaxies can be seen around the cluster and a few foreground stars with prominent diffraction flares scattered throughout the image.

This particular galaxy cluster is called eMACS J1823.1+7822 and is located about nine billion light-years away in the constellation Draco. It is one of five extremely large galaxy clusters that Hubble discovered in hopes of measuring the strength of these gravitational lenses and providing insight into the distribution of dark matter in galaxy clusters. Powerful gravitational lenses like eMACS J1823.1+7822 can help astronomers study distant galaxies by acting as giant natural telescopes, magnifying objects that would otherwise be too faint or distant to be recognized.

This multi-wavelength image combines data from eight different filters and two different instruments: the Hubble Advanced Survey Camera (ACS) and the Wide Field Camera 3 (WFC3). Both instruments are capable of imaging astronomical objects in only a small portion of the electromagnetic spectrum, using filters that allow astronomers to capture images of objects at precisely chosen wavelengths. Combining observations of different wavelengths allows astronomers to build a more complete picture of an object’s structure, composition, and behavior than visible light alone can provide.