The Hubble Space Telescope image of the inner region of Abell 1689, an immense cluster of galaxies located 2.2 billion light-years away (Image: NASA/ESA/JPL-Caltech/Yale/CNRS)
Dark energy has been described as the greatest puzzle of our universe. This mysterious force, discovered in 1998, is pushing the universe apart at ever-increasing speeds and astronomers have now devised a new method of measuring it. Using NASA's Hubble Space Telescope, astronomers were able to take advantage of a giant magnifying lens in space – a massive cluster of galaxies – to narrow in on the nature of dark energy. Their calculations, when combined with data from other methods, significantly increase the accuracy of dark energy measurements and may eventually lead to an explanation of what the elusive phenomenon really is.