The physics that underlies the accelerating cosmic expansion is unknown. This “dark energy” and the equally mysterious “dark matter” comprise 96% of the mass-energy of the universe and are outside the standard model. Recent advances in optics, detectors, and information technology, has led to the design of a facility that will repeatedly image an unprecedented volume of the universe: LSST. For the first time, the sky will be surveyed wide, deep and fast. The history of astronomy has taught us repeatedly that there are surprises whenever we view the sky in a new way. I will focus on the technology of LSST, and review several independent probes of the nature of dark energy and dark matter. These new investigations will rely on the statistical precision obtainable with billions of galaxies.

The Large Synoptic Survey Telescope (LSST) is a planned, large-aperture, wide-field, ground-based telescope that will survey half the sky every few nights in six optical bands from 320 to 1050 nm. It will explore a wide range of astrophysical questions, ranging from discovering “killer” asteroids, to examining the nature of dark energy.
The LSST will produce on average 15 terabytes of data per night, yielding an (uncompressed) data set of over 100 petabytes at the end of its 10-year mission. Dedicated HPC facilities will process the image data in near real time, with full-dataset reprocessings on annual scale. A sophisticated data management system will enable database queries from individual users, as well as computationally intensive scientific investigations that utilize the entire data set.
In this talk, I will review what LSST will deliver once operational, discuss implications of LSST-sized data sets on astronomy in the 2020s, and argue that we as a community need to prepare in advance to make the best use of the upcoming petascale datasets.