using the hubble space telescope, a double ring has been found by raphael gavazzi of the stsci and tommaso treu of the university of california, santa barbara. this arises from the light from three galaxies at distances of 3, 6, and 11 billion light years. such rings help in understanding the distribution of dark matter, dark energy, the nature of distant galaxies, and the curvature of the universe. the odds of finding such a double ring are 1 in 10,000. sampling 50 suitable double rings would provide astronomers with a more accurate measurement of the dark matter content of the universe and the equation of state of the dark energy to within 10 percent precision.