The universe is brighter than we thought, a NASA rocket experiment finds. The NASA sounding rocket experiment has discovered a surprising excess of infrared light in the dark space between galaxies, a diffuse cosmic glow that is as bright as all known galaxies combined. It is believed that the glow comes from orphaned stars expelled from galaxies.

These findings redefine what scientists consider galaxies. Galaxies do not necessarily have a boundary of stars, but rather stretch out to great distances, forming a large, interconnected sea of stars.

Observations from the Cosmic Infrared Background Experiment, or CIBER, are assisting in settling a debate on whether the background infrared light in the universe, previously detected by NASA’s Spitzer Space Telescope, stems from the streams of cast off stars too far away to be seen individually, or alternatively from the first galaxies that formed in the universe.

Lead author of a new paper detailing results from the rocket project and an astronomer at the California Institute of Technology (Caltech) and NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California, Michael Zemcov, said in a statement, “We think stars are being scattered out into space during galaxy collisions.” He continued, “While we have previously observed cases where stars are flung from galaxies in a tidal stream, our new measurement implies this process is widespread.”

Mike Garcia, program scientist from NASA Headquarters, added, “It is wonderfully exciting for such a small NASA rocket to make such a huge discovery. Sounding rockets are an important element in our balanced toolbox of missions from small to large.”

According to NASA Sounding Rocket Science, sounding rockets carry scientific instruments into space along parabolic trajectories, providing nearly vertical traversals along their upleg and downleg, while appearing to “hover” near their apogee location.