Artist's conception of neutron stars merging
With three gravitational-wave observatories online (see LIGO and VIRGO), observers were able to accurately triangulate the most recent burst of gravitational waves that rumbled past Earth on August 17. With a much smaller part of the sky to scan, astronomers were able to pin down the source of the event--the merger of two neutron stars in a distant galaxy producing a kilonova--and track its evolution through observations in gamma-rays, x-rays, visible light, infrared and radio waves.
This unprecedented series of observations let astronomers compare the neutron-star merger to theoretical predictions in great detail, including proving that most of the elements heavier than iron are forged in these collisions. They also provided new information about the accelerating expansion of the universe. In addition, it demonstates that astronomers now have a huge new window into the universe that promises a stream of surprises and new discoveries.
For great pictures, animations and a more in-depth description of this breakthrough and its implications, click here.