"The universe is 13 billion years old, but things change every second," Sweeney said.
The full extent of that activity cannot be captured by most of today's powerful telescopes, which are designed to peer very deeply into very small parts of the sky.
But LSST's 8.4-meter (28-foot) lens will continuously shift position, moving three degrees every 30 seconds.
"Over ten years we will cover every piece of sky 2,000 times," Sweeney said.
As images are generated, each one will be digitally compared with the previous image of the same section of sky.
Any differences will be immediately highlighted for further study and possible follow-ups with other telescopes.
Cristina Beldica is an LSST project manager for the National Center for Supercomputing Applications in Urbana, Illinois.
With Google's help, she said, "the data management system [will provide] real-time alerts to enable time-critical discoveries that must be followed up by other telescopes."
In addition to detecting changes, LSST will help scientists better understand the mysterious dark matter and dark energy now believed to dominate the universe.
A central product will be better three-dimensional "mass maps" showing where light from distant galaxies is bent by concentrations of dark matter.
(Related news: "Dark Matter Mapped in 3-D, Scientists Report" [January 8, 2007].)
Telescope for the People
Google already provides sophisticated online and desktop maps based on satellite and other imagery of Earth, the moon, and Mars.
The firm recently struck a partnership with NASA to assist in developing new applications and public interfaces for the space agency's data sets.
LSST director Anthony Tyson said that while it is too early to say what the public interface with LSST will be like, Google engineers will have plenty of opportunities for innovation.
"Once you have 80 parameters describing each one of ten billion galaxies and other objects, there is a lot you can imagine doing," Tyson said.
"There will be multidimensional graphics, movies, and many other products providing new modes of interaction with the data."
Such resources should make LSST a boon to science educators.
Grade school classes may be able to take a virtual tour of the solar system, watch for tens of thousands of newly discovered asteroids, or track changes through a particular patch of sky.
James Kaler is an astronomer at the University of Illinois in Urbana-Champaign and editor of the Cambridge Encyclopedia of Stars.
He said that for professional and amateur astronomers as well as the general public, "the impact of the LSST-Google combination should be terrific.
"The data stream will be so great that the pros would never—even with their immense computing power—be able to examine it fully," Kaler said.
The project "will in effect place a large, sophisticated telescope into the hands of anyone who wishes to use it for research, education, or other purposes. Personally, I can't wait."
Alan Hale, co-discover of the Hale-Bopp comet and founder of the Cloudcroft, New Mexico-based Earthrise Project, said that LSST's potential impact on astronomical discoveries is difficult to predict.
He does believe that LSST and other sky surveys will make visual discovery of new comets by amateurs a thing of the past.
But he notes that many comets are now being discovered by amateurs using publically available images from the Solar and Heliospheric Observatory (SOHO), an orbital telescope launched in 1996.
Comet discoveries via LSST," Hale said, "will probably take place in a manner similar to that of the SOHO comets."
Free Email News Updates
Best Online Newsletter, 2006 Codie Awards
Sign up for our Inside National Geographic newsletter. Every two weeks we'll send you our top stories and pictures (see sample).
SOURCES AND RELATED WEB SITES