California Institute of Technology News Release

2007 August 22

PASADENA, Calif.- Panoramic images of the sky obtained at Palomar Observatory are a major part of "Sky in Google Earth," a new product released today by Google Inc. Sky in Google Earth contains images of the entire celestial sphere, showing hundreds of millions of stars, galaxies, and other cosmic wonders. Also today, scientists at the California Institute of Technology are releasing a related application showing in real time the locations of cosmic explosions and flares in this new vista of the universe.

The basic layer of the Sky in Google Earth images is derived from the digital versions of the sky surveys conducted by astronomers in the 1980s and 1990s at Caltech's Palomar Observatory in the northern hemisphere and at the Anglo-Australian Observatory in the southern hemisphere. The original sky survey photographs were digitized at the Space Telescope Science Institute in Baltimore, Maryland, providing the roadmap for the Hubble Space Telescope's pointings into the sky, and feeding numerous other scientific studies over the years.

The northern sky images were obtained using the Palomar Observatory's 48-inch Samuel Oschin telescope, where many pioneering and historical sky surveys have been conducted since the 1950s. The telescope continues to provide a steady stream of scientific data and results.

"We are excited that the general public can now easily view this remarkable scientific data set," says S. George Djorgovski, Caltech professor of astronomy, who was the principal investigator of the Digital Palomar Observatory Sky Survey. "It will feed the sense of wonder and exploration of the universe by students and curious people everywhere."

Most of the stars, nebulae, and galaxies seen in the Sky in Google Earth images will not change much for millions or billions of years. However, the universe also contains much more dynamic, rapidly changing phenomena, such as exploding and colliding stars, which cannot be easily represented in static images. Caltech scientists have provided an enhancement to Google Earth to help convey such events to the general public.

Google's technology enables a creation of layers, popularly known as "mashups," where lists of particularly interesting locations can be attached to the maps. One such application is released today by a team of scientists at Caltech's Center for Advanced Computing Research as a part of the center's VOEventNet project. The goal of this project is to enable automated dissemination and follow-up of various transient phenomena in the night sky within minutes of their detection.

The Caltech application layer provides real-time updates of locations of two types of transient events in the sky: cosmic gamma-ray bursts and so-called gravitational microlensing events. The gamma-ray bursts are spectacular explosions believed to be caused by the deaths of massive stars as they collapse to produce black holes. The microlensing events are caused by the passage of a star in front of another, background star; its gravitational field acts as a lens, temporarily making the background star appear much brighter, and sometimes even revealing the presence of planets around it.

"This gives the general public a front-row seat to watch some of the most dynamic astronomical investigations unfold, at the same time as the scientists discover these cosmic events," says Roy Williams, who is the leader of the VOEventNet team. "It also illustrates the potential of information technology in conveying the excitement of modern astronomical research to general audiences."

The Caltech scientists plan to expand their service to include other types of astronomical events and transient phenomena in the sky. "We would like to better engage the amateur astronomy community in the discovery process," says Andrew Drake, a team member who participated in the development. "They can follow up the interesting events, and may even generate genuine discoveries themselves."

Other members of the Caltech team are Matthew Graham and Ashish Mahabal. The work at Caltech was supported in part by the National Science Foundation and private donors.

The Caltech mashup can be obtained at http://voeventnet.caltech.edu/google/VOEventNet.kmz. It will be also linked at http://earth.google.com/gallery.

The newest version of Sky in Google Earth can be downloaded from http://earth.google.com

The VOEventNet project website: http://voeventnet.caltech.edu.

The Digital Palomar Observatory Sky Survey website: http://www.astro.caltech.edu/~george/dposs.

Palomar Observatory website: http://www.astro.caltech.edu/palomar.

The Samuel Oschin Telescope: http://www.astro.caltech.edu/palomar/sot.html.

This story was originally titled "Palomar Observatory's Sky Survey is the Cosmic Canvas in the New Google Sky".

Copyright © 2007, Brian Webb. All rights reserved.