Sloan Digital Sky Survey

Today, we understand that the universe consists not only of stars and planets, but also of galaxies, clusters of galaxies, streams and clumps of gas, and a component of unseen (or dark) matter. To learn more about these objects, we must first know where to find them, how they interact, and how they change over time. Many structures cover large areas of sky; others are so rare that we must look at millions of objects to find just one example. These ideas have guided the many projects in the last century to map the universe, over ever larger areas, to ever greater depths, and over an ever increasing range of wavelengths. Complete, scientific sky surveys are the best technique we have for discovering new objects and interactions of objects. Once we find enough objects, we can study them to derive the basic physical properties of the universe.

This survey, the Sloan Digital Sky Survey (SDSS), was created to study how galaxies cluster on the largest scales. The SDSS will map these clusters in greater detail than any survey so far. If we know how galaxies cluster, we can learn something about how microscopic matter and energy variations evolved from the earliest moments after the big bang, more than 12 billion years ago, into the structures we see today.
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thanks to DANGEROUSMETA!