The Large Synoptic Survey Telescope (LSST), the top ground-based priority in Astro2010 Decadal Survey report, will carry out an imaging survey covering the sky that is visible from Cerro Pachon in Northern Chile. The LSST design, with an 8.4m (6.7m effective) primary mirror, a 9.6 sq.deg. field of view, and a 3.2 Gigapixel camera, will allow about 10,000 square degrees of sky to be covered using pairs of 15-second exposures twice per night, every three to four nights on average, with typical 5-sigma depth for point sources of r=24.5 (AB). With about 1000 observations in ugrizy bands over a 10-year period, these data will enable a deep stack reaching r=27.5 (5-sigma, point source) and faint time-domain astronomy. The measured properties of newly discovered and known astrometric and photometric transients will be publicly reported within 60 sec after closing the shutter. The resulting hundred-petabyte imaging dataset will enable scientific investigations ranging from the properties of near-Earth asteroids, to characterizations of dark energy from strong and weak lensing, galaxy clustering, and distant supernovae. These data will represent a treasure trove for follow-up programs using other ground and space-based telescopes, such as fast-response fast-cadence photometric observations, spectroscopy and polarimetry, as well as for facilities operating at non-optical wavelengths and for gravitational wave programs.