The European Southern Observatory created the zoomable image by using computers to combine thousands of individual images, resulting in a 9-billion-pixel image that would, if printed at the resolution of a typical book, measure 30 feet long and 23 feet tall, the Los Angeles Times reported Thursday.
The images used to create composite were gathered using the ESO's 161-inch Visible and Infrared Survey Telescope for Astronomy at the Paranal Observatory in Chile.
The telescope was used to explore the central core of the Milky Way because that portion of the galaxy is visible only from the Southern Hemisphere, astronomers said.
Of the 173 million individual objects in the photo composite, 84 million could be positively identified as stars. The rest were either more distant objects, such as other galaxies, or objects that could not be accurately identified, they said.