Space isn’t as dark as we think, NPR reports. Using images taken by New Horizons, a spacecraft now more than 6 billion kilometers from Earth, scientists analyzed blank areas of space without bright stars. Even after accounting for light from surrounding stars, known galaxies, and even camera equipment, about half of the light in these seemingly barren areas of space remained unexplained, they report. This light could originate from faint, unknown galaxies that tools like the Hubble Space Telescope cannot detect or it could even be generated by an as-yet-unidentified phenomenon associated with dark matter, scientists say.