National Geographic : 2009 Jul
• lms---the early universe was a thick plasma and as alive with sound as a drummers conven- tion. Certain tones resonated in the primordial plasma, like the tones of struck wine glasses, and these harmonies, etched into sheets of galaxies that today shamble across billions of light-years, contain precise information about the nature of dark matter and dark energy. If astronomers can map these large-scale structures accurately, they should be able to identify the signatures of dark matter and dark energy in the big bang s harmonics. e Sloan Digital Sky Survey, a pio- neering wide-angle study, captured some of this information when it mapped the sky from 1999 through 2008. e LSST is designed to go much deeper into cosmic space. It may not resolve the mysteries, but, predicts Tyson, "it will go a long way toward showing what dark energy and dark matter aren t." The LSST s photographic "speed" will also give astronomers a better look at events too short-lived to be readily studied today. Most astronomers, even amateurs using backyard telescopes and o -the-shelf digital cameras, reg- ularly record eeting events of unknown origin. You take a series of digital exposures, and in one of them a spot of light appears where none was before or a er. It may have been a cosmic ray hitting the light-detection chip, a high-velocity asteroid hurtling through the eld of view, or a blue are on the surface of a dim red star. You just don t know, so you shrug and move on. Because the LSST will take so many repeat ex- posures of the entire sky, it could resolve many such riddles. Tomorrow s enormous telescopes will do as much in one night as today s do in a year, but that will not necessarily render the older tele- scopes obsolete. When the giants come on line, says Scott Fisher, "the Geminis of today will become the telescopes that get to go out and do the surveys," nding interesting phenomena for the largest scopes to investigate in detail. "It s like a pyramid, and it feeds both ways: When a really big tele- scope nds something exciting that we can t spend every night observing, the astronomers can apply for time on a smaller tele- scope to, say, check it out every clear night for a year and see how it changes over time." Orbiting space telescopes are opening up another dimension. NASA s Kepler satellite, which launched in March 2009, is methodically im- aging the constellation Cygnus, looking for the slight dimming of light caused when planets--- some perhaps Earthlike---transit in front of their stars; Geo Marcy s team will then use Keck to scrutinize stars agged by Kepler to con rm that they have planets. In the future, pairs of mirrors deployed in orbit and linked by laser- ranging systems could attain the resolving pow- er of telescopes measuring thousands of meters across. One day, observatories sitting in craters on the far side of the moon may probe the uni- verse from surroundings ideally quiet, dark, and cold. The coming combination of smart satellites talking to big, increasingly automated ground telescopes, themselves linked together by ber-optic networks and employing arti - cial intelligence systems to search out patterns in the torrents of data, suggests a process as much biological as mechanical, akin to the evo- lution of global eyes, optic nerves, and brains. that each movie is really two movies---the one you make, and the one you say you re going to make while rais- ing the money. e point is that nobody can accurately predict the outcome of any genuinely WHAT'S NEXT? EVEN BIGGER TELESCOPES, WITH THE CAPABILITY TO SHOOT COSMIC PICTURES FASTER, IN EVEN GREATER DETAIL.