RocketSTEM Issue #11 - April 2015 | Page 110

Abell 62. 1703 Located in the northern celestial hemisphere, Abell 1703 is composed of over one hundred different galaxies that act as a powerful cosmic telescope, or gravitational lens. The gravitational lens produced by the massive galaxy cluster in the foreground (the yellow mostly elliptical galaxies scattered across the image) bends the light rays in a way that can stretch the images and so amplify the brightness of the light rays from more distant galaxies. In the process it distorts their shapes and produces multiple banana-shaped images of the original galaxies. The result is the stunning image seen here - a view deeper into the Universe than possible with current technology alone. Abell 1703 is located at 3 billion light-years from the Earth (redshift 0.26). Credit: NASA, ESA, and Johan Richard (Caltech, USA) “The Hubble Space Telescope is the greatest astronomical instrument yet created by humankind. Since its launch 25 years ago, it has provided discoveries well beyond what we expected to learn. “Some of the most dramatic discoveries have been of distant galaxies in the early universe. Due to the bright emission in the near-infrared from our Earth’s atmosphere, only Hubble can obtain the deep imaging necessary to discover galaxies hailing from less than one billion years after the Big Bang. These observations over the past few years have proved astounding – the early universe is teeming with galaxies! “This is one of Hubble’s lasting legacies – a small telescope, with a mirror the size of your typical NBA center – can teach us about how galaxies are growing only 500 million years after the Big Bang. This is one dramatic bang for your buck!” — Dr. Steven Finkelstein Assistant Professor of Astronomy University of Texas at Austin