NASA's Hubble Telescope Reveals Space Invader: Abell 68 Galaxy Cluster

NASA has found a space invader--in the form of a very distant galaxy cluster. The NASA/ESA Hubble Space Telescope has picked out Abell 68, a cluster that appears to look like a small alien due to a distortion.

Abell 68 acts as a natural lens in space. It brightens and magnifies the light coming from very distant background galaxies. This lensing then creates a landscape of arc-like and mirror images of background galaxies. While the foreground cluster is 2 billion light-years away, the lensed images come from galaxies that are far behind it.

So how does this distortion occur specifically? The huge concentration of matter deforms the fabric of spacetime, which in turn distorts the path that light takes when it travels through the cluster. The phenomenon allows the Hubble telescope to observe galaxies that might otherwise be invisible into ones that can be observed with relative ease, according to NASA.

Although the resulting galaxies are heavily deformed, this process, called gravitational lensing, is hugely valuable in cosmology--the branch of astronomy that covers the origins and evolution of the universe.

The image itself comes from the infrared channel of Hubble's Wide Field Camera 3 combined with near-infrared observations from the Advanced Camera for Surveys. Infrared images in general are useful for studying distance objects since their light is redshifted into the infrared due to the expansion of the universe. The infrared images also allow researchers to peer through dust clouds which are opaque to visible light.

Soon, though, researchers may be able to see more than ever. Hubble's ability to see distant objects will be enhanced with the start of a new observing campaign. The mission plans to combine the power of Hubble with the natural gravitational telescopes of high-magnification clusters of galaxies. It will study six different galaxy clusters before the launch of the James Webb Space Telescope in 2018.