We tend to think that light travels in a straight line, but this is not always the case in our universe, when strong enough, gravity can pull photons of light out of their trajectory. Hubble spotted a phenomenon known as gravitational lensing, which occurs when gravity bends light in super cool and interesting ways.
"The center of this image from the NASA/ESA Hubble Space Telescope is framed by the tell-tale arcs that result from strong gravitational lensing, a striking astronomical phenomenon which can warp, magnify, or even duplicate the appearance of distant galaxies," wrote NASA in its statement about its most recent image.
"Gravitational lensing occurs when light from a distant galaxy is subtly distorted by the gravitational pull of an intervening astronomical object. In this case, the relatively nearby galaxy cluster MACSJ0138.0-2155 has lensed a significantly more distant inactive galaxy — a slumbering giant known as MRG-M0138 which has run out of the gas required to form new stars and is located 10 billion light-years away." Turns out, astronomers can put gravitational lensing into use as a natural magnifying glass. Which in turn "allows them to inspect objects like distant dormant galaxies which would usually be too difficult for even Hubble to resolve."
Eight different infrared filters
In order to get this mesmerizing image, researchers had to use eight different infrared filters spread across two of Hubble’s most advanced astronomical instruments: the Advanced Camera for Surveys and the Wide Field Camera 3. "These instruments were installed by astronauts during the final two servicing missions to Hubble and provide astronomers with superbly detailed observations across a large area of sky and a wide range of wavelengths," explained NASA.
Hubble throughout the years has brought us some of the most amazing awe-inspiring images known to mankind. If you want to see more read this article on 15 of the best photos from the instrument and five more in celebration of Christmas.