Illustration of colliding planet embryos

Cosmic Cannonball |  Astronomers have discovered one of the fastest-moving stars ever seen, using a combination of data from NASA’s Chandra X-ray Observatory, the international ROSAT satellite, and the 0.9-meter telescope at Cerro Tololo Inter-American Observatory. A team observed a neutron star known as RX J0822-4300 over a period of about five years. During that span, three Chandra observations clearly show the neutron star moving away from the center of the Puppis A supernova remnant and the stellar debris field created during the same explosion in which the neutron star was formed, about 3,700 years ago. By combining how far the neutron star has moved across the sky with its distance from Earth, astronomers determined the star is moving at more than 3 million miles per hour. NASA Release

Image Credit: Chandra: NASA/CXC/Middlebury College/F.Winkler; ROSAT: NASA/GSFC/S.Snowden et al.; Optical: NOAO/AURA/NSF/Middlebury College/F.Winkler et al.