Look up at the night sky and, if you're away from city lights, you'll see stars. The space between those bright points of light is, of course, filled with inky blackness.
Some astronomers have wondered about that all that dark space--about how dark it really is.
"Is space truly black?" says Tod Lauer, an astronomer with the National Optical Astronomy Observatory in Arizona. He says if you could look at the night sky without stars, galaxies, and everything else known to give off visible light, "does the universe itself put out a glow?"
It's a tough question that astronomers have tried to answer for decades. Now, Lauer and other researchers with NASA's New Horizons space mission say they've finally been able to do it, using a spacecraft that's travelling far beyond the dwarf planet Pluto. Continue here....
-- Nell Greenfieldboyce
