The National Virtual Observatory (NVO) will unite astronomical databases of many earthbound and orbital observatories, taking advantage of the latest computer technology and data storage and analysis techniques. Credit: G. Bacon and J. Gitlin (STScI/AVL)

"... I think this is likely to change astronomy as we know it."

The Internet brings its users the world online. Astronomers from 17 research institutions have announced that they're starting an ambitious new project to put the universe online.

The National Virtual Observatory (NVO), headed by astronomer Alex Szalay of The Johns Hopkins University and computer scientist Paul Messina of the California Institute of Technology, will unite astronomical databases of many earthbound and orbital observatories, taking advantage of the latest computer technology and data storage and analysis techniques. The goal is to maximize the potential for new scientific insights from the data by making them available in an accessible, seamlessly unified form to professional researchers, amateur astronomers and students.

The new project is funded by a five-year, $10 million Information Technology Research grant from the National Science Foundation. Organizers characterize their goal as "building the framework" for the National Virtual Observatory.

Szalay, the Alumni Centennial Professor of Astronomy in Johns Hopkins' Krieger School of Arts and Sciences, views the NVO (http://us-vo.org) as a significant step forward in formalizing a third major approach to scientific research that's been growing in usefulness and popularity in recent years.

"First, you have science conducted through theoretical models," he explains. "Next, you have science tested through experiments. The new approach, scientific exploration through computational methods, is developing in response to the tremendous volumes of data we're starting to gather in many of the sciences."

According to Szalay, advances in technology and technique now annually double the total information astronomers gather each year from observatories.

"If we do not develop ways to distill information and insights from these floods of data, we will end up like shipwrecked sailors on a desert island, surrounded by an ocean of salt water and unable to slake our thirst," co-principal investigator Messina says.

Messina notes that the NVO was inspired by the Digital Sky Project (http://www.npaci.edu/envision/v15.3/digitalsky.html), an NSF-funded project led by Caltech computer scientist Tom Prince that is working to make data from four different astronomy databases available through one seamless web portal.

The NVO will take some of its basic techniques from an earlier multi- disciplinary, multi-institutional NSF-funded project led by Szalay. That project, started two years ago, worked to develop different and improved methods for accessing and analyzing large volumes of scientific data.

A key challenge for the NVO will be developing ways to simultaneously analyze data from several of the dozens of astronomical databases available today. "Each of those databases is organized differently, which makes it quite difficult to perform analyses of data from several collections simultaneously," Messina explains. "Those kinds of investigations promise to yield important scientific discoveries, though, so the NVO will work to streamline our ability to do such analyses."

Computationally, NVO will do this work through a set of approaches and techniques developed in the 1990s known as "grid" computing. Grid computing lets scientists in multiple institutions easily and rapidly share data and other problem-solving resources.

Szalay compares the effects of this technique for users to the electronic power grids set up for large regions of the United States. Power grids gather and use resources from a variety of sources, but without the user ever being aware such gathering processes are occurring.

"We'll rely on the same kinds of techniques to transfer data and [run computer programs] in a transparent way," Szalay says. "You won't necessarily know where your computer program is running or be aware that data's being accessed in one database or another -- just that the work is getting done."

Ethan Schreier, an astronomer at the Space Telescope Science Institute who is a member of the NVO project Executive Committee, says astronomy has been at the forefront of archiving and sharing data electronically for at least two decades.

"Astronomers first started adopting standards for data exchange in the late 1970s, were aggressive in developing standard data analysis systems that other astronomers could share, and then built data archives for use by the broad scientific community," says Schreier, who is an adjunct professor at Hopkins. These archives, Schreier notes, have so much data in them that they can be used to produce new discoveries many years after the data was originally gathered.

Messina emphasizes that the focus for the NVO won't be to impose a particular set of database standards but to encourage their continued creation, with the expectation that competition among the standards will encourage further development of standards that large segments of the astronomical community agree on. He notes that they already have an encouraging indicator of the NVO's potential for expanding consensus: all the major archives of astronomy data in the United States are already signed up to participate in the NVO, and links are being created to similar initiatives in Europe and Asia.

"This project will reach across the astronomical community," Szalay says. "The number of people interested has been growing exponentially, and I think this is likely to change astronomy as we know it."

Organizers are planning to keep the NVO "virtual" -- not located in any one facility -- and accessible enough for non-specialists like science teachers or students to use.

"A major goal for the NVO is to provide a window on the universe for students, teachers, backyard astronomers and the interested public," says Bob Hanisch, NVO project manager at the Space Telescope Science Institute. "The NVO will enable the public to explore directly the wealth of information from society's investment in our national research facilities."