Measurements of the universe's darkness performed with NASA's New Horizons probe reveal an unexplained glow to the Universe. Scientists present these results in an online session at the 237th American Astronomical Society meeting, "New Horizons Detection of the Cosmic Optical Background," on Jan. 13 at 12:40 pm EST.

"The Universe is dark, but not as dark as we thought," said National Science Foundation NOIRLab scientist Tod Lauer, who led the research team along with Marc Postman of the Space Telescope Science Institute.

Read more in these features from the Space Telescope Science Institute and The National Science Foundation's NOIRLab

This artist's illustration shows NASA's New Horizons spacecraft in the outer solar system. In the background lies the Sun and a glowing band representing zodiacal light, caused by sunlight reflecting off of dust. By traveling beyond the inner solar system and its accompanying light pollution, New Horizons was able to answer the question: How dark is space? At lower right are background stars of the Milky Way. (Credit: STScI/Joe Olmsted)