SDSS SkyServer

Public Access to the Sloan Digital Sky Server Data




Further Reading

Personal SkyServer

The Team





Many fields are now coping with a rapidly mounting problem: how to organize, use, and make sense of the enormous amounts of data generated by today’s instruments and experiments. Ideally, this data should be accessible to  scientists and educators, to minimize the gap between current research, education and public knowledge, and to facilitate integrative research.

The goal of this project is to develop an internet data resource in astronomy.  Because of the nature of the data and analyses required, the data will be widely distributed rather than centralized, an approach that may prove to be applicable in many other fields. 

Today, instruments like the following are being used for systematic surveys of our galaxy and of the distant universe:

The Hubble Space Telescope [HST]
Chandra X-Ray Observatory [Chandra]
Sloan Digital Sky Survey [SDSS]
Two Micron All Sky Survey [2MASS]
Digitized Palomar All Sky Survey [DPOSS] 

Together they will give us an unprecedented catalog to study the evolving universe—provided that the data can be systematically studied in an integrated fashion.

The amount of data available is very large and growing.  Yearly advances in electronics enable new instruments that double the data we collect each year. A night’s observation is a few hundred gigabytes. The processed data for a single spectral band over the whole sky is a few terabytes. Plus, the most beneficial studies require combining data from multiple instruments.

Astronomers need to look for patterns in the data, both spectral and temporal, known and unknown, and use these to study various object classes.  They need to have a variety of tools at their fingertips: a unified search engine, to collect and aggregate data from several large archives simultaneously, and a huge distributed computing resource, to perform the analyses close to the data, in order to avoid moving petabytes of data across the networks.

Because of the amount of data, researchers cannot each have a separate copy of the data; the resources must be combined and shared.  So, the astrophysical community is developing the World-Wide Telescope – often called the Virtual Observatory [VO].   In this approach, the data will primarily be accessed via digital archives that are widely distributed.  The actual telescopes will either be dedicated to surveys that feed the archives, or telescopes will be scheduled to follow-up ‘interesting’ phenomena found in the archives.

But the Virtual Observatory is not just for astronomers.  It offers the opportunity to teach science in a participatory way to a variety of students.

Astronomy has a special attraction for all, as demonstrated by planetariums, amateur telescopes, and text-books. Even very young children can be engaged in many different sciences via astronomy – astronomy has strong ties to physics, chemistry, and mathematics. Astronomy can be used as a vehicle for introducing the basic concepts of all these fields and also used to teach the process of scientific discovery.

We can give students direct access to a wonderful scientific instrument. They can use it to make discoveries on their own. Very interesting projects and lectures can be built using the Virtual Observatory tools and data.

The Virtual Observatory can also be used to teach computational science. Traditionally, science has been either theoretical or empirical. In the last 50 years, computational science emerged as a third approach, first in doing simulations and now increasingly in mining scientific data. Indeed, most scientific departments now have a strong computational program. The Virtual Observatory is a unique tool to teach these skills.

Like astronomy, the Virtual Observatory is a world-wide effort. Initiatives are underway in many countries with a common goal: join the diverse worldwide astronomical databases into a single federated entity facilitating new research for the worldwide astronomy community. The European national and international astronomy data centers are leading an effort funded by. the European Union. The Astronomical Virtual Observatory (AVO) is led by the European Southern Observatory and also backed by the European Space Agency. The EU also sponsors re-search in pipeline processing technology to handle the anticipated terabyte data streams from future large survey telescopes. The UK funds the AstroGrid Project to investigate distributed data archives Grid technology. Japan and Australia are setting up their own large archives. In the United States, the National Science Foundation sponsors development of the information technology infrastructure necessary for a National Virtual Observatory (NVO). There is a close cooperation with the particle physics community, through the Grid Physics Network (GriPhyN). NASA supports astronomy mission archives and discipline data centers, while developing a roadmap for their federation.

Impressively, these projects are all cooperating, and are working toward a future Global Virtual Observatory to benefit the international astronomical community and the public alike. There are similar efforts under way in other areas of science as well. The VO has had and will have significant interactions with other science communities, both learning from some and providing a model for others.


NGC 5792
A highly inclined spiral galaxy. The bright red star superposed is in our own Milky Way and makes a colorful counterpart to the blue galaxy, although the two are otherwise unrelated.







NGC 428

A spectacularly blue nearby spiral galaxy. The blue color is an indication of very active star formation in this galaxy.

















Globular cluster Palomar 5
A loose cluster of stars located in the halo of the Milky Way.