Data Sonification: Caldwell 73

  • Released Wednesday, December 23, 2020

Located 40,000 light-years from Earth in the constellation Columba, this globular cluster is called Caldwell 73 or NGC 1851. A globular cluster is a spherical group of stars that are gravitationally bound to each other, with most of the stars concentrated at the cluster’s center.

As the radar scans around in this sonification, the radius of the stars is mapped to pitch, so stars farther from the center are higher pitched. The entire image is converted to the sound of a choir, while the orange and red stars are represented by a marimba, and the blue stars are represented by a glockenspiel.

Credit: SYSTEM Sounds (M. Russo, A. Santaguida)

For more information about the Hubble Space Telescope and its images, visit

Master Version

Horizontal version. This is for use on any YouTube or non-YouTube platform where you want to display the video horizontally.


Please give credit for this item to:
NASA's Goddard Space Flight Center

Release date

This page was originally published on Wednesday, December 23, 2020.
This page was last updated on Wednesday, May 3, 2023 at 1:44 PM EDT.


This visualization is related to the following missions: