That's the projected galaxy haul of the Large Synoptic Survey Telescope, currently under construction in Chile. Starting around 2023, the LSST camera's 3,200 megapixels will soak up 15 terabytes of data every night, which will fill the biggest astronomical database ever built. Computer scientist Lior Shamir of Lawrence Technological University in Michigan says the amount of data defies comprehension. "With just a mountain of images, no one will ever inspect them one by one. You can never make a discovery," he says.