alistic representation of the celestial vault. There is, however, a small trade-off (which some users argue is not so small). Because Google Sky uses a latitude and longitude projection, the stars in the original images were significantly distorted between seven and eight degrees of both celestial poles. Hence, these regions were replaced with a lower-resolution view of the sky derived from the Tycho II star catalog. The stars in those polar regions are obviously not as sharp as the other parts of Google Sky’s sky (they exhibit a decided radial stretch from the pole outward), but they are properly scaled and their colors are based on real color data.
Like Google Earth, Google Sky utilizes Keyhole Markup Language (KML), which is an XML-based language for displaying geographic data and visualizations for Web-based 3D browsers. In this case, KML files display not mountains and cities, but celestial objects as well as annotated data files. Users can add their own content by converting it into a KML file and posting it at either Google Sky or on the Web so that others can add it, if they choose. One such example is an orrery that shows the positions of the planets in the solar system with respect to each other on a particular night.
in context with their surroundings in the immensity of space. For example, when you zoom in on the region of sky known as Hubble Ultra Deep Field, you’ll discover it is just one-tenth the diameter of the full Moon, small enough to cover with a pencil tip held at arm’s length. But when you follow the clickable links, you’ll discover this tiny bit of celestial real estate contains more than 10,000 galaxies.
Lior Ron, a product manager for Google Sky, says the program encourages users to see Earth in perspective with the vastness of the universe. “We hope that Google Sky will bring about a fundamental change in the way we perceive our place in the universe, just as Google Earth changed how we look at our planet,” he says. “A number of [theorists] have talked to us about how looking at things like the IRAS [infrared astronomical satellite] infrared map in the Web version of Google Sky really brought a physical reality to their mental model of the sky that they hadn’t had previously,” says Ron.
One of the most fascinating aspects of WWT and Google Sky is how they allow you to view celestial objects
The advent of these virtual telescope programs is being celebrated by astronomers, but as Djorgovski notes, measuring their impact on education is tricky. Carol Christian, an astronomer at the Space Telescope Science Institute, home of the Hubble Space Telescope, agrees. “It’s something that’s going to take years,” she says. “This isn’t something you can do in a couple of months. Right now it’s a field of dreams. We built it. Will they come?”
Christian believes the key to Google Sky’s success will be innovative educators. “I’m coming across this problem that the kids are way ahead of teachers,” she says. “We need to get teachers. . . to understand that the student of the future and the worker of the future needs to be facile with finding information, analyzing it, applying critical thinking, making decisions, and finding the data they need to answer a question.”
To date, both the WWT and Google Sky claim millions of active users. If these numbers are any indication, both applications will soon be an essential part of the science classroom and museum, as well as a powerful tool that will enable researchers to access, publish, and update data in context with the very universe they study. The virtual telescope is a field of dreams with unlimited possibilities, all of which will be explored and augmented by users in ways we can only speculate about now. In the not-too-distant future, computer scientists may look back on the rise of applications such as the WWT and Google Sky as forerunners of the much ballyhooed Web 3.0 era, which would be fitting since it promises to be light-years ahead of today’s Internet.
a view of the andromeda Galaxy, a spiral galaxy located more than two million light-years away, as it appears in Google sky.
based in Derwood, mD, Jeff Kanipe is the author of The Cosmic Connection: How Astronomical Events Impact Life on Earth.
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